U.S. patent application number 09/141277 was filed with the patent office on 2001-06-14 for integrated seat control with adaptive capabilities.
Invention is credited to NEWMAN, TODD, PERRIN, RANDY, SWAN, JEFFREY, WASHELESKI, JOHN.
Application Number | 20010003806 09/141277 |
Document ID | / |
Family ID | 27385628 |
Filed Date | 2001-06-14 |
United States Patent
Application |
20010003806 |
Kind Code |
A1 |
SWAN, JEFFREY ; et
al. |
June 14, 2001 |
INTEGRATED SEAT CONTROL WITH ADAPTIVE CAPABILITIES
Abstract
A motor control system employed in a mechanism including
displacers driven by motors, for example, a vehicle seat control
system, includes motor operation parameter detection or simulation
as inputs to adaptive algorithms to simplify the control system.
The adaptive algorithms compensate for the interference with
detection of generated or sensed pulses in previous pulse counting
implementations. The seat control permits additional functions to
be performed without numerous sensors, power controls and robust
demands required in previous systems for controlling motors.
Inventors: |
SWAN, JEFFREY; (HERSEY,
MI) ; PERRIN, RANDY; (CADILLAC, MI) ; NEWMAN,
TODD; (REED CITY, MI) ; WASHELESKI, JOHN;
(CADILLAC, MI) |
Correspondence
Address: |
RONALD M NABOZNY
BROOKS & KUSHMAN
1000 TOWN CENTER
22ND FL
SOUTHFIELD
MI
480751351
|
Family ID: |
27385628 |
Appl. No.: |
09/141277 |
Filed: |
August 27, 1998 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09141277 |
Aug 27, 1998 |
|
|
|
08936479 |
Sep 18, 1997 |
|
|
|
6049748 |
|
|
|
|
08936479 |
Sep 18, 1997 |
|
|
|
08918918 |
Aug 27, 1997 |
|
|
|
5982253 |
|
|
|
|
Current U.S.
Class: |
701/49 ;
296/63 |
Current CPC
Class: |
B60N 2/002 20130101;
B60N 2/0248 20130101; B60N 2/666 20150401; H03H 7/0115 20130101;
H01R 13/719 20130101; H03H 7/06 20130101; B60N 2/976 20180201; B60N
2/66 20130101 |
Class at
Publication: |
701/49 ;
296/63 |
International
Class: |
G05B 023/00 |
Claims
What is claimed is:
1. A position controller for at least one displacer driven by at
least one motor with a displaceable shaft, the controller
comprising: a control module for selectively delivering electrical
power to the motor and a monitor for the delivery of electrical
power to the motor; a sensor means for detecting displacement of
the motor shaft; and a position limiter controlling delivery of
power to the motor in response to said sensor and said monitor,
said limiter including compensation for relative displacement
between the shaft and the displacer, and a compensator for falsely
sensed or unsensed displacement of said shaft.
2. The invention as described in claim 1 wherein the motor has a
rotary shaft with a commutator and said sensor comprises an
interface circuit for generating pulses in response to rotation of
the commutator.
3. The invention as described in claim 2 wherein said position
limiter includes a compensator for determining the absence of a
pulse expected during rotation by monitoring motor current and
detecting said pulses from said interface circuit, and generating
an adaptive feedback pulse in response to the absence.
4. The invention as described in claim 2 wherein said position
limiter includes a predictor that determines an expected pulse
position as a function of rotating shaft speed, time and pulse
count.
5. The invention as described in claim 3 wherein said position
limiter adapts the controller to terminate power to the motor prior
to an end of travel position of said at least one displacer in
response to said compensator.
6. A seat controller for managing displacement of at least one
component of a seat mechanism by operation of a motor, the control
comprising: a motor monitor sensing rotation pulses of said motor;
a motor operation monitor sensing at least one motor operating
parameter for the motor actuation; and a compensator for adjusting
the displacement in response to said rotation pulses and said at
least one motor operating parameter.
7. The invention as described in claim 6 wherein said compensator
comprises a commutator current and/or voltage pulse counter and a
motor current detector.
8. A method for simplifying control of at least one motor and
determining the position of a displacer moved by said at least one
motor, the method comprising: generating a pulse or a pulse
simulation for each movement of said motor over a predetermined
increment of motor operation parameter; determining a location of
the displacer by adaptively accounting for each said pulse or pulse
simulation; and compensating for undetectable pulses and for motor
operation parameter variations by indicating position of the
displacer and adjusting the indicated position of said displacer in
response to said accounting.
9. The invention as described in claim 8 wherein said predetermined
increment of motor operation parameter comprises a sensor response
to at least one moving motor part, timing a duration from an
actuation command, detecting a motor current and detecting a motor
voltage.
10. The invention as described in claim 9 wherein said motor
includes a rotary shaft and a commutator and said moving a motor
part is detected by sensing commutator pulses.
11. The invention as described in claim 9 wherein said moving a
motor part is detected by sensing a shaft displacement.
12. An apparatus for controlling movement of a displacer
comprising: at least one motor; at least one coupling for moving
the displacer in response to operation of said motor; at least one
sensor providing signals in response to a parameter associated with
at least one of said motor, said coupler and the displacer; and a
controller with adaptive processing for monitoring and controlling
said parameter, said adaptive processor including a compensator
supplied with simulated limits of said parameter, a comparor for
comparing said simulated limits of said parameter with said sensed
parameter, and a control signal adjustor determining motor position
in response to said comparison.
13. The invention as described in claim 12 wherein said simulated
limits and said parameter are electrical noise parameters.
14. The invention as described in claim 12 wherein said simulated
limits and said parameter are electrical power to said motor
including energization errors at startup.
15. The invention as described in claim 12 wherein said variable
limits and said parameter are electrical power to said motor
including de-energization errors.
16. The invention as described in claim 12 wherein the motor has
brushes and mechanical commutator for selectively energizing and
commutating the electrical currents to motor coil windings, and
wherein said parameter comprises commutating pulses.
17. The invention as described in claim 12 wherein the motor is a
brushless type motor and wherein said parameter comprises energy
applied to motor windings.
18. The invention as described in claim 17 wherein said parameter
sensor includes an electronic interface circuit for detecting
current in said windings.
19. The invention as described in claim 18 wherein said parameter
sensor includes a band pass filter to select a predetermined range
of commutation pulse frequencies.
20. The invention as described in claim 18 wherein said parameter
sensor includes a detector for motor current in unenergized
windings.
21. The invention as described in claim 18 wherein said control
signal adjustor includes a simulator for selectively energizing
motor windings in response to said parameter sensor.
22. The invention as described in claim 12 wherein said parameter
sensor is a displacement sensor.
23. The invention as described in claim 12 wherein said motor is a
linear motor.
24. The invention as described in claim 12 wherein said controller
and said parameter sensor are integrally coupled with the motor
housing.
25. The invention as described in claim 12 wherein said signals
comprise a first time derivative of said parameter.
26. The invention as described in claim 12 wherein said signals
comprise a second time derivative of said parameter.
27. The invention as described in claim 12 wherein said displacer
is a support for an automotive component.
28. The invention as described in claim 12 wherein said controller
includes a sensor for determining physical obstruction to movement
of the displacer.
29. The invention as described in claim 12 wherein said controller
includes automatic memory positioning.
30. The invention as described in claim 12 and further comprising a
communicator.
30. The invention as described in claim 12 and further comprising a
communicator.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of an application
Ser. No. 08/936,479 filed Sep. 18, 1997, entitled Massage
Controller Module (MCM), which is a continuation-in-part of an
application Ser. No. 08/918,918, entitled "In-Line Module For
Attenuating Electrical Noise", filed in the U.S. Patent and
Trademark Office on Aug. 27, 1997, and commonly owned.
TECHNICAL FIELD
[0002] This invention relates to vehicle seat control systems with
advanced control, diagnostics, and functional features in the seat
control system including motors and motor responsive sensors.
BACKGROUND ART
[0003] Increasing numbers of vehicles have an electrical motor
driven, mechanical or pneumatic, multiple support adjustment seats
with a controller system offering optional upscale features.
Vehicle is herein construed as including car, truck, rail train,
airplane, and the like. The features may include multiple
displacements of several seat portions and incorporation of a seat
lumbar support. In addition, a position sensor and a memory module
for closed loop feedback positioning of various supports in the
seat relative to the user seat position is selected by the user or
automatically set by controller module memory settings. For
example, this allows a person, identified as and with a controller
# one, to adjust various seat adjustment positions to an individual
preference, and then set memory # one for these settings. When the
recall position # one switch actuator is manipulated, for example,
a recall button is pressed, the seat will return to the multiple
adjusted preference settings set by driver # one.
[0004] Likewise, person # two may set memory # two and recall
position # two, if the system is designed for additional personal
settings. The basic seat lumbar adjustment control offers no lumbar
position sensor. The optional system upgrade version typically
includes a modular controller having the seat position memory
feature which necessarily includes a seat position sensor
system.
[0005] However, these previously known seating systems require
sensor systems for precise displacement and positioning of the seat
portions, and each movement may require its own set of input
switches, limit switches, sensors or the like, as well as power
supply for the sensors and the sensor responsive equipment. Such
components can add a substantial amount of hardware, complexity and
cost to the system and increase the size of the system and the time
and the cost of production.
[0006] Although some previously known motor control systems have
recognized that commutator pulses may be used to gauge motor
rotation speed, such systems have not been readily applicable to
seat assemblies. Motor brush or other dust may interfere with the
detection of pulses, and may create false pulses. In addition,
in-rush current at motor start-up and initial movement may
interfere with detection of pulses that should have occurred. As a
result, previously known pulse counting applications did not
accurately gauge positioning of the components moved by a motor, or
permit repeatability of positioning, for example in a seat
mechanism, involving starting and stopping over time. As a result,
separate sensor systems have been relied upon to control
positioning.
[0007] Stepper motor controllers have been utilized by the machine
industry for some time. An example would be indexing to position to
place a part or remove a part. In addition, there is usually a
feedback sensor as a redundant to verify the accuracy. However,
these systems are far too expensive for adaptation to automotive
implementation such as seating control features.
[0008] As a result, traditional seat control systems have grown in
size, weight, complexity and cost due to increasing consumer demand
for new features.
SUMMARY OF THE INVENTION
[0009] The present invention overcomes the above-mentioned
disadvantages by utilizing motor operation parameter detection or
its simulation with adaptive algorithms to simplify a control
system. The adaptive algorithms compensate for the interference
with detection of pulses in previous pulse counting implementations
and avoid error accumulation in the maintenance or adjustment of
the position of a displacer. Preferably, the control system, for
example, a modular system of seat control features, may be
functionally improved without adding a wide variety of hardware and
controls that was previously implemented for each new feature for
vehicle seating system applications. As described in this
application, the term motors is to be understood as generally
referring to motion generators creating forces that can act upon
displacers, regardless of whether the force generator is a rotary
shaft motor or a linear actuator.
[0010] The preferred configuration uses commutator pulses and
monitors the time between pulses for speed as well as position.
Each time the motor brushes move past a commutator segment, the
position can be determined and stored by the control based on the
gear drive ratio of motor movement to linear movement. As a result,
the displaced item's position is more accurately determined than
with previous position sensors. The use of commutator pulses can be
difficult because detection may be interfered with by missing
commutator pulses, during startup, during shut down or due to noise
conditions. As a result, a control according to the present
invention includes compensation, for example, an algorithm within
the microcontroller that identifies these conditions and makes the
proper adjustments to the position record in the microcontroller
memory, therefore maintaining high accuracy for the brush motor
type systems. Moreover, the system reduces wire gauge requirements,
for example, for power delivery to the motor and reduces
requirements for signal communications.
[0011] The compensation may also be accomplished using a brush
motor with an external sensor, such as a Hall effect or encoder
that will provide pulses, as the motor assembly moves. However,
although the external sensor provides the same type of information
as the commutator pulses, such a sensor requires additional
components.
[0012] Another embodiment for such compensation would be a stepper
motor control, which is a brushless motor control. These brushless
motors come in two forms, sensor feedback and sensorless. The
brushless motor is different as it requires a control to provide a
signal to one or more of multiple windings, which then instructs
the motor to make a movement; i.e., the control will move the motor
in increments based on controlling the energization of each of the
windings. However, one disadvantage is some method needs to
validate that the movement did occur since a control pulse or
direction sent to the motor does not guaranty that the motor has
turned. In the brush type motors, sensing the commutator pulse is a
response that indicates the motor has moved. By using one of the
windings not energized in the brushless motor, a pseudo commutator
pulse will be generated by the magnetic field, which then will tell
the control that the motor has turned.
[0013] An additional reduction of components and their
corresponding space and weight may be achieved by utilizing a brush
or brushless concept as outlined above, as well as integrating the
electronics and motor in conjunction with a gear box. Preferably,
the gear box eliminates the many motors previously required, and
substitutes associated mechanical, electrical, electronic or
pneumatic couplings selectively engageable with a single motor that
can be used to position each of the individual features. By
substituting the gear box for each individual motor, the system
current draw is reduced, the number of motors is reduced to one,
and wiring complexity and component packaging are reduced.
[0014] Complementary in-line modules incorporating monitoring and
control algorithms cooperate with signal and power control as in
previous application Ser. No. 08/936,479, entitled MASSAGE
CONTROLLER MODULE (MCM) and incorporated herein by reference. As a
result, desirable features such as massage control can be easily
incorporated and provide numerous advantages to an existing seat
control system by encouraging blood circulation, stretching and
relaxing muscles, varying strain on skeletal members, varying
strain on cartilage between articulating skeletal members and also
producing a relaxed feeling without substantial changes to the
system or its controls.
[0015] An in-line module interfaces and integrates with existing
and future automotive seat control hardware and software, as
pertinent, to provide complementary functions. A controller module
may be relatively small compared to discrete component control
systems and size which requires only minimal or no wiring change to
the existing seat control circuitry, yet appears to be virtually
nonexistent to and allows full priority to all functionality of the
existing seat controls and actuators.
[0016] The existing seat controller module can be supplemented or
replaced with an alternative control module offering current
control features plus increased functionality upgrades. It should
be understood that for seat control systems having memory set and
recall features, the existing electronic seat controller module
either can be complemented by addition of the module to the system,
or alternatively, can be replaced by another version of the
controller which incorporates all functionality into one single
unit. In seat control systems having no memory set and recall
features, a simple seat control system having no electronic seat
controller module will be referred to as a seat control, and as
such the module will preferably be a complementary addition to the
system.
[0017] In addition, the motor controller system of the present
invention may be employed in substantially different displacement
mechanisms powered by a motor, regardless of whether the
implementation is automotive related. Nevertheless, another example
of automotive applications related to occupant support is that
operator responsive actuators may be displaced according to the
present invention to improve ergonomics without complications the
hardware and production requirements, and the associated costs,
traditionally associated with such improvements in vehicles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be more clearly understood by
reference to the following detailed description of a preferred
embodiment when read in conjunction with the accompanying drawing
in which like reference characters refer to like parts throughout
the views and in which:
[0019] FIG. 1 is a diagrammatic, partly schematic view of a vehicle
seat control system with position memory and implementing a motor
position responsive control module with adaptive pulse compensation
according to the present invention;
[0020] FIG. 2a is a schematic view of portions of the system shown
in FIG. 1;
[0021] FIG. 2b is a schematic view of other portions of the system
shown in FIG. 1;
[0022] FIG. 2c is a schematic view similar to FIG. 2b but showing a
modified embodiment of a power supply (L) without a power limiter
to the load for a control according to the present invention;
[0023] FIG. 2d is a schematic view similar to FIGS. 2b and 2c but
showing a modification to the output logic decoders and drivers in
a manner that expands I/O port capacity for an improved control
according to the present invention;
[0024] FIG. 3 is a top view of the preferred module housing;
[0025] FIG. 4 is a front edge view of the preferred module
housing;
[0026] FIG. 5 is a side edge view of the preferred module
housing;
[0027] FIG. 6 is a flow chart diagram of a program algorithm
employing a pulse count compensation control in accordance the
present invention;
[0028] FIG. 7 is a diagrammatic view of a further modified seat
control system simplified according to the present invention;
[0029] FIG. 8 is a side elevation view of the control shown in FIG.
7;
[0030] FIG. 9 is a block diagram similar to a portion of FIG. 6 but
showing a modified control algorithm portion incorporated in the
present invention; and
[0031] FIG. 10 is a block diagram similar to FIG. 9 but showing an
alternative control algorithm incorporated in the present
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0032] Referring first to FIG. 1, a seat control apparatus 10
includes improvements in the method and structure for providing
advanced seat control functions with automatic feedback control
systems. These methods and structures for automatic control are
applicable to other diverse smart control systems unrelated to
automotive seating, but are well adapted to seat controls including
seat heating, multiple seat cushion positioning, multiple-axis seat
positioning, and the like described in detail in this application.
However, the invention is not so limited. Fast acting real time
microprocessor algorithms with memory storage means and appropriate
interface circuitry choices contribute to improved control system
response detection means for various modes of fault conditions
including obstacle or obstructed movement detection, electrical
shorts, electrical open circuits, and abnormal inputs.
[0033] The preferred embodiment illustrated demonstrates
significant applicability and cost effectiveness for various types
of motion control systems, regardless of whether they are related
to automotive seating systems. Advantages and benefits are due in
part to the sensing of motor actuation electrical current signals
and commutation pulses with interface circuitry, the microprocessor
algorithms used, and the counters alone and in combination with
each other as to determine both device position, motion and
loading. Electronic circuit means and methods for reading and using
motor commutation pulses, motor current signals, clock pulses,
microcontroller counting registers, and digital processing
algorithm routines of the microcontroller dynamically determine and
adaptively respond to device movement characteristics. Accordingly,
while not limited to automotive seat systems, substantial
econometric value can be realized from the invention as shown.
[0034] Referring to FIGS. 1 and 2, a motor vehicle seat control
system 10 is thereshown employing a control mechanism 12 (FIG. 1)
for driving a seat mechanism 16. In either event, the seat
mechanism 16 includes motors 18 for driving portions of the seat
with respect to other portions of the seat or with respect to the
support for the seat. In the preferred embodiment, a first version
20 (FIG. 1) of the vehicle seat system 10 includes a memory set and
recall system for repositioning all movable features of the seat to
a predetermined position selected by an occupant. The features of a
non-memory version employs simpler controls, as indicated at blocks
22, for adjusting seat positions such as seat height, back
inclination, forward and reverse positioning, and tilting of the
seat base. Moreover, it will be understood that the present
invention can also be implemented with a wide variety of seat
systems regardless of the particular vendor or the models provided
by the vendor to provide improved operations such as a massage
function without interfering with seat control, seat mechanism, or
electrical connections of the seat controls. In addition,
additional controls may be provided by the controller for one or
more drive motors 53 coupled to drive displacement apparatus 55,
for example, brake or throttle pedal positioners, or steering wheel
positioners, external to the seat mechanism 16. Moreover,
substantially any motor driven system can be improved by
incorporating the control method and apparatus of the present
invention.
[0035] In the preferred embodiment, a seat displacement mechanism
16 includes a displacer, for example, a lumbar support 32 as
disclosed in U.S. application Ser. No. 08/936,479 incorporated
herein by reference, driven by a first motor 24, that controls a
movement mechanism 26 for displacement of the lumbar support 32
upwardly and downwardly through the seat back. A second motor 28
controls a lumbar support extender 30 and it governs the degree to
which the lumbar support extends outwardly from the seat back
toward a spinal curvature of an occupant. Both mechanisms 26 and 30
affect the position of the lumbar support 32 of the seat mechanism
16.
[0036] Referring to FIGS. 3-5, the massage control module 34 is
relatively small so as to be able to be mounted under the drivers'
or front passengers' seat and can integrate and interface with
existing hardware and wiring harnesses, as applicable, to provide
lumbar massage and other functions. In some cases, it may be
practical to modify or redesign the wiring harness to facilitate
integration of the massage control module into the system.
[0037] In the case of a non-memory type seat control system 22
which offers no existing optional lumbar support position sensor
40, the lumbar support position can alternatively be analytically
derived in various ways such as an absolute encoder on the motor
where added expense can be accommodated. A resolver on the motor or
a simple incremental encoder on the lumbar support drive motor may
be used in less expensive embodiments. With resolvers and encoders,
appropriate algorithms such as these taught in the present
application and motor stall current detection can be used to
determine lumbar position, preferably within a tolerance of one
motor revolution where tens, hundreds or orders more of revolutions
are required between end of travel (EOT) limits.
[0038] Various module control modes such as manual, automatic,
sleep (power save), and teach are preferred for incorporation with
many systems. Manual mode allows full manual control to override
and possibly discontinue automatic functionality. Automatic mode
allows automatic powered control of the system outputs. Sleep mode,
also known as power save mode, is favored for battery powered
applications wherein battery charge is to be conserved. Sleep mode
is typically entered automatically after an I/O activity timer
times out indicating no controller I/O activity has occurred for
some amount of time. When in sleep mode, the control module goes
into a very low quiescent current drain operation, awaiting some
input signal to reset the timer effecting a "wake up" thereby
causing it to return to full power operational mode. Teach mode is
an option whereby a portion of the functionality of the system
control is taught or programmed by a user.
[0039] Utilizing DC motor current commutation pulses sensed by the
described interface means provides a simpler and lower cost means
to detect motor rotation and therefore seat cushion position than
by previously disclosed means of an analog output external absolute
position encoder sensors. By this means of motor pulse counting
with appropriate microcontroller counter circuits, the present
invention enables additional functions to be performed cost
effectively and with reduced lead time for implementation or
production vehicles. Moreover, it becomes possible to add memory
positioning and massage functions to seat control systems without
the previous necessity of having available or adding seat cushion
position feedback sensors. Position counters can be reset with the
increase in motor current and/or with the increase in time between
commutation pulses that indicates that the motor is approaching an
end of travel stalling condition. Input (EOT) reset description.
The control can adaptively learn the number of counts from one
stall limit to the opposite stall limit such that it can
predictively turn off shortly before both stall limits. Such a
current control reduces peak load torques, improving fatigue life,
reducing the potential for unwanted noises otherwise produced by
application of full power into a physical stop, and substantially
reduces wire gauge necessary to operate the motor.
[0040] Moreover, the end of travel (EOT) limit detection can also
be employed to reset calculated position or to zero-in counters so
that less accurate sensor algorithms or simulations initially
relied upon to represent position, do not accumulate and introduce
location error throughout the life of the system. An example of a
control system determining position with a less precise
determination of displacement than in the preferred embodiment is
shown in FIG. 9. The position is simulated by estimating the motor
movement as a function of time and the previously known or
estimated rate of displacement. Another example is shown in FIG. 10
where position detection is simulated by counting pulses and
calculating or estimating the missing pulses once speed and pulse
counting has stabilized.
[0041] Addition of the seat position set, recall, massage, and
massage teaching functions can be easily implemented via the
existing up and down switches, because the controller can respond
to inputs by such means as application of simultaneous switch
activation (for example up and down switches at the same time,
timed activation (the length of time for which a switch actuation
is maintained), and/or activation sequence (for example one quick
up then one quick down or one quick down then one quick up). As
with previous applications, an in line electrical filter module
will be a preferred option with the drive motors.
[0042] An alternative embodiment uses a distributed control scheme
based on a master/slave concept fully described here later. In this
embodiment, SMART MOTOR endcaps integrate the control system having
integrated microcontrollers within the motor housing to perform
certain local functions, reducing the need for higher pin count
master microcontrollers and extra external circuitry in the
adaptive seat module. However, the invention as described here can
also be implemented as either a set of discrete components,
circuits or submodules, or implemented as a single custom
integrated circuit or set of custom integrated circuits, or
implemented as some combination of custom integrated circuits and
commercial components.
[0043] Inputs are represented in FIG. 2a by block A that
incorporates input protection and filtering. Analog motor current
can be sensed to correlate with motor loading conditions.
Incremental motor movement can be sensed by the conversion of the
characteristic alternating component of motor current commutation
pulses into digital form for position encoder counting, the count
which represents actuator position. FIG. 2a schematic block F
incorporates inputs for motor commutator pulses. FIGS. 2b, c, d
schematic block J incorporates the active filters for sensing motor
current commutation pulses. The component values are adjusted by
software adaptation in the controller or hardware component
selection to work with each motor based upon its anticipated
current range and commutation pulse amplitude. For example, all
sensing shunts such as the resistors shown in FIGS. 2b, c, d block
J could be replaced with a wirewound resistor, wirewound coil,
simple inductor or solid state device. In addition, software
filters can be employed in the controller 12.
[0044] Controller output is shown in FIGS. 2b, 2c, and 2d. Motor
driver decode logic is shown in FIGS. 2b, c, d block H. Of course,
other ways to expand the I/O port pins of the microprocessor are
also available and may be included in the present invention, and
multiple or integrated processors may be employed as desired.
[0045] Motor drivers are shown in FIGS. 2b, c, d block K. Motor
speed output drive (Block K, FIGS. 2b,c) can be controlled via
typical drive methods such as pulse width modulation (PWM), analog
output, and phase control. Relay control of motor drive is shown in
FIGS. 2b, c block I. Redundant means for isolating the motor drives
is achieved by the relay 47 coupling the power supply circuit in
block L of FIGS. 2c, d to the relay drivers I.
[0046] As shown in FIG. 2a at block C, the controller and memory
interaction is disclosed. Closed loop motion feedback control of
speed and/or direction are economically performed using motor
incremental position feedback signals derived from motor current
commutation pulses. At block J in FIGS. 2b, c, d, the motor load
current signal is AC coupled, amplified, band pass filtered, and
compared to a reference DC signal, thus producing a digitized
encoder signal used as one of the inputs to microcontroller counter
routines to digitally count up and down to represent output device
mechanical position. Resetting of the counter can be accomplished
in response to switch input, end of travel stall current detection,
excessive time of actuation in either direction, and/or by sensing
reversal of direction via an analog position sensor.
[0047] An alternative to the circuit J for actuator position input
is by use of an incremental or absolute analog encoder, for
example, by a film resistor on a crank gear coupling a motor shaft
to a displacer, coupled, for example, to a lumbar support 32.
Another alternative for displacer position input is by use of an
incremental or absolute digital encoder, for example by conductor
patterns on an insulating substrate over a crank gear in a
displacement mechanism as substitute for commutator pulses.
[0048] In the controller 12, motor speed is determined by time, for
example, the number of clock pulses between motor commutator
pulses. Preferably, motor acceleration is determined by the change
in the number of clock pulses between at least two successive
commutator pulse increments. Motor jerk is preferably determined by
the change in the acceleration between at least two successive
commutator pulse increments. Higher order derivatives of position
are possible, but typically not utilized because of increasing
sensitivity to noise with higher orders of algebraic
differentiation.
[0049] Block B providing a power supply to microprocessor and block
G providing a power supply to relays allowing connection of the
motors (system) in FIG. 2a comprise the system power supply
elements. Alternative constructions are also within the scope of
the present invention.
[0050] Block J in FIGS. 2b, 2c and 2d comprises the circuits which
sense the motor commutator pulses, provide filtering and deliver
the pulses to the microcontroller 44. The motor load current signal
is AC coupled, amplified, band pass filtered, and compared to a
reference DC signal, thus producing a digitized encoder signal used
by microcontroller counter routines to count up and down to
represent output device mechanical position.
[0051] FIG. 2a block A shows protection means for the controls,
such as the switches, employed to actuate the displacers in the
seat mechanism 16. The inputs include the heated seat temperature
sensor input, and switches such as memory 2 recall switch, memory 1
recall switch, memory set switch, recline back switch, recline
forward switch, horizontal forward switch, horizontal back switch,
front vertical up switch, front vertical down switch, rear vertical
switch, rear vertical down switch, lumbar up switch, lumbar down
switch, lumbar in switch, heated seat high switch, heated seat low
switch, head rest up switch, head rest down switch, heated seat
indicator, seat sensor input, ignition 1 signal input, and park
signal.
[0052] FIG. 2a blocks D and E show control communications interface
(I/O) for the microprocessor. Module system monitoring and
diagnostics communication capability is a useful feature which can
significantly simplify system maintenance by providing history of
operational information and/or fault codes. Utilization of
microcontroller control algorithms and routines incorporating
watchdog capability, to trap and recover from software addressing
problems, is incorporated to the microcontroller algorithms for
reliable operation. The watchdog routine also works in cooperation
with fault and system monitoring and diagnostics routines which can
store and communicate abnormal operation states, fault conditions,
or operational conditions which are or might potentially be or
cause an operation error or damage.
[0053] Operation fault detection monitoring can be employed for use
and equipment protection. Fault detection includes such types of
faults as short circuit, open circuit, abnormal conditions,
hard/soft obstacle detection, stall protection, over voltage, under
voltage over temperature, under temperature, over speed, and under
speed. Information from types of fault condition detection
monitoring can be included in diagnostics communication capability
for reasons such as functional operation verification.
[0054] Communication to and/or from the module can be achieved by
such energy transmission modes as electrical conduction, E-field,
M-field, EM-field, sonic, ultrasonic, vibration, pneumatic,
hydraulic, thermal, and the like. Depending on the type of
communication used, remote control and communication can be via a
wireless method such as radio transmission, infrared transmission,
and sonic transmission. The system is adaptable with various
communication modes including standard as well as custom hardware
and software protocols such as serial bus, parallel bus,
multiplexing (MUX), demultiplexing (DEMUX), wave division MUX,
infrared data exchange, for example, per IRDA, pulse width
modulation (PWM), pulse position modulation (PPM), amplitude
modulation (AM), frequency modulation (FM), frequency shift
modulation (FSM), and the like. For example, in USA automotive
systems, a favored communication standard is SAE J1850 as shown at
49 in FIGS. 1 and 2. Suffice it to say that single direction or
bidirectional communication enables remote control of parameters,
functions, timing, inputs, outputs, algorithm and routine
programming, and even interactive encryption. By these means it is
possible to add a control module remotely, near the controlled
output, near the power supply or even in a convenient hidden
location and thereby communicate control signals.
[0055] The microcontroller includes inputs, outputs and software
algorithms within programmed memory for calculating the
compensation provided as a result of response to actual or the
simulation of a response to actual conditions that adjusts the
control output for position of the relevant displacer. The
microcontroller includes software for accepting user entered inputs
via switches. Preferably, the software has known software filters
to selectively filter out noise and switch contact bounce so that
the control algorithm will only act upon valid input stimulus.
[0056] The software in microprocessor 44 controls external output
circuitry that drives an electrical load, typically an electric
motor. The output drive circuitry in K and I may be
electromechanical in nature, a relay, or solid state. In the case
of a motor load where an external current shunt is in use, the
external drive circuitry can provide commutation pulse information
and load current information to the microcontroller for the
software to act upon. The commutation pulses of the motor can be
filtered external to the microcontroller using known passive or
active filter techniques as shown in FIGS. 2b, c, d at block J.
Alternatively, the microcontroller software could include a digital
filter to accomplish the same degree of filtering and replace the
external circuitry.
[0057] In addition, compensation for commutation pulse
discrepancies can be provided by a digital filter. For example,
such a filter could include a missing pulse detection algorithm.
When commutator pulses are counted, the pulse count can yield
physical position information for various mechanisms that are being
driven by a motor. Because position is directly related to pulse
count, compensation for pulse anomalies, for example, by missing
pulse detection, would allow for continued correct operation of the
attached load when one or more commutator pulses are missing. The
software can filter the incoming signal and determine that a
periodic pulse pattern is present. If the expected pattern is not
present, for example by predicting characteristics of an expected
pulse, and comparing the pulse prediction with an pulse
characteristic, a pseudo pulse can be generated by the missing
pulse detection algorithm to take the place of the missing pulse
for purposes of position compensation.
[0058] Another example of a compensation algorithm 55 for missing
initial or start-up pulses is shown in FIG. 6. The software in the
controller may calculate masked pulses ((A/D*X)/256+b) and adjust
counters as appropriate. This compensates for pulses masked by
inrush current at startup and electrical braking at shutdown. A/D
is system voltage, X and b are constants in ROM defined for the
system by characterizing each motor. Thus, upon any actuation of
the manual switch for a motor, the controller applies electrical
power to the motor until commutator pulses are detected. Once
commutator pulses are detected, the calculation simulates the motor
position that otherwise is calculated in response to motor current,
time period of current application and motor speed, thus, further
reducing the need for sensor components and robust wiring or
communication requirements.
[0059] As the level of missed or extra pulses may reach a
threshold, the operator of the system can be informed of the
problem with the motor as with vehicle on board diagnostics, so
that maintenance may be performed, while still allowing the system
to operate normally. The software can determine that a commutator
pulse is degenerating, that is to say, not similar to other
commutator pulses, or going to fail soon. In this case, the
operator of the system could be informed by a signal to an
indicator that preventive maintenance should be performed before
failure occurs. Alternatively, the missing pulse detection software
could act upon pulses generated from other sensors, for example,
hall effect sensors, variable reluctance sensors, and others that
could be installed if desired.
[0060] In a system where load current is being monitored, an
optional feature permits the control software to determine when an
electrical fault, for example, a short circuit of the load occurs,
to prevent battery drainage or current flow that damages the
system. A rapid increase in load current beyond a given threshold
is an indication that the output drive circuitry is shorted.
Typically external circuitry will disconnect power from the shorted
load or connection. Preferably, the software can determine that a
short circuit condition exists, and the controller reacts so that
the output driver can be disabled and the operator notified of the
fault condition. The software could also retry the output at a
given rate, say once per second, to determine if the fault
condition still exists. If the fault condition is corrected, the
system will resume normal operation. Similar to short circuit
operation, the software could determine stalled operation. If a
motor load is energized and no commutation pulses are received (or
other feedback), the software can determine that the mechanism is
stalled. The software can again retry the function at a given rate,
and the operator could be notified of a fault condition.
[0061] The microcontroller may incorporate communications software.
Having communications with the adaptive seat module (ASM) as shown
at 49, in FIG. 1, to an external controller will enable user
inputs, such as switches, to be brought into the module through a
standard communication input and the removal of for example, switch
inputs A, their respective switches and the individual wires from
the various inputs. Communication capability will also enable the
ASM to exchange diagnostic information with other controllers. High
level communications, such as SAE J1850 or CAN, could be used to
communicate from the ASM to another vehicle controller. Low level
communications, standard serial protocol (SCI and others) could be
used to transfer information and control signals to other
microcontrollers located at the individual load. For example, a
motor could have a small microcontroller incorporated into its
circuitry along with passive or active filters and power drivers in
integrated motor caps as discussed previously. The ASM central
microcontroller 44 (master) would take instructions from the high
level communications bus and then in turn, transmit specific
instructions to individual loads such as the motors. The small
microcontroller (slave) integrated with the motor would then
interpret the instruction and act on it by providing drive signals
to a load such as a motor.
[0062] The ASM differs from a simpler massage control module (MCM)
in several important ways. In fact, the MCM is a subsystem of the
ASM. Basically, the MCM, shown at FIG. 1 with the blocks 22
removed, contains the same microcontroller and power supply
circuitry, but has only Switch inputs and power outputs specific to
lumbar positioning and massage. While the same generic blocks exist
in FIGS. 2a-d, the implemented circuit count is smaller because of
the need for fewer motors (only two operated in one version of the
module that operates up, down, in and out for support 32, in MCM,
as shown in the schematic portion of Box 16, versus seven in the
preferred version of seat controller for ASM). Specifically, MCM is
implemented by use only of circuits in FIG. 2a (portions of block
A, D, E & F, all of blocks B, C & G) and FIG. 2b (portions
of block H, I, J, K). Referring to the FIG. 1 representation, the
adaptive seat system block diagram includes items deleted from ASM
to result in MCM. The deleted features include switch inputs such
as recline back, recline forward, horizontal back, horizontal
forward, front vertical up, front vertical down, rear vertical up,
rear vertical down, heated seat high, heated seat indicator, head
rest up and head rest down. In addition, an MCM module does not
require power outputs such as front vertical motor up, front
vertical motor down, recliner motor forward, recliner motor back,
horizontal motor back, horizontal motor forward, heated seat +,
heated seat -, head rest motor up, rear vertical motor up, and rear
vertical motor down. However, the selection of features to be
controlled by one module may be varied as desired to meet the goals
assigned to the system.
[0063] Alternative to determining lumbar support position by direct
measurement of some physically sensed variable is the option of
empirically measuring the relative amounts of time, under ambient
conditions of temperature, voltage, and lumbar load, to drive the
lumbar support from either end of travel (EOT) limit to the present
home position and from each end of travel (EOT) physical limit to
the opposite as determined by lumbar drive motor stall current
detection or end of travel limit Switches. Preferably, the control
module 12 uses some signal such as current, time, temperature,
voltage, motor pulses, movements or other inputs and an algorithm
or look-up tables for determination of position and generation of
automated commands for returning a support to home position at the
finish of the displacement function.
[0064] Preferably, both the memory type module and the non-memory
type may use the same module housing 42, printed circuit board,
microcontroller 44, and algorithms in the software programs.
Different components may populate the printed circuit for the
memory type versus the non-memory type massage control module as
previously identified without departing from the present invention.
The memory type massage control module uses its microcontroller
inputs and outputs, having tri-state capability, to poll both
massage control module and external interface circuitry. Polling
discerns the type of external interface Switching and electronics
in a seat control or seat control module from different vendors and
for different models and thus to determine which particular control
algorithms are appropriate, for example as described below, and
determines the biasing, to be applied to certain microcontroller
outputs for correct operation. The module provides watchdog
capability to trap and recover from any software or addressing
problem which may prevent normal operation.
[0065] In the case of the control module which interfaces with a
non-memory type seat control with portions 22, the physical
packaging and the printed circuit board may be identical, although
the components populating the printed circuit board differ.
[0066] The control module 12 appears virtually nonexistent to the
independent and priority functionality of an existing seat control
system 42 that may be incorporated in a system 16. Thus, the
massage control module is transparent to the higher priority of all
functions of the existing seat control system 42. To accomplish
this, a massage control module may intercept the true lumbar
support position signal from a sensor or the motor pulse detector
and provide a simulated virtual lumbar support position signal to
the existing seat controller 42. By providing a virtual lumbar
support sensor signal steadily representing a lumbar position to
the seat controller, the massage control module can then move the
lumbar support 32 without the seat controller of existing system 42
being aware of the true and changing lumbar support position. This
prevents the seat controller from generating an error condition
caused by movement of the lumbar support 32 in a system of known
type modified by installation of a control system according to the
present invention.
[0067] The MCM may also intercept other signals, such as both the
UP and DOWN switch inputs from a lumbar switchpad which is either a
special control panel or switch, or alternatively, a combination
actuation of existing switch controls, receiving the motor drive
outputs from the seat controller system 42, passing along simulated
signals and driving loads consistent with functional requirements
of both the seat controller of the system 42 and the massage
control module. This gives dependent and lower priority control of
the lumbar support 32 to the massage control module so that it can
perform the massage function, although virtual priority and virtual
independent control always remains with the seat controller of the
seat system 42. This method of functional control modification is
based upon the in-line modular massage control module intercepting
real signals and/or power and transparently substituting simulated
signals and/or power between the seat controller of the system 42
and external devices such as sensors, motors 18, and switches on
switch pad 46. The case of the non-memory system 22 is simpler by
virtue of not having to interface sensor signals to the seat
control 16.
[0068] The position of the lumbar support 32 may also be
intercepted directly and exclusively from a lumbar support position
sensor by the massage control module as an analog signal via a
SENSOR IN input terminal. This analog signal is replicated or
functionally modified as described below at the massage control
module to provide a signal at a SENSOR OUT output terminal that is
a simulated virtual representation of the lumbar support position
to the seat controller. This simulated virtual SENSOR OUT signal
value is generated and maintained within specific required accuracy
and precision by digital pulsing of a pushpull circuit, preferably
using software algorithms and decision making processes within the
microcontroller 44 of the massage control module. Using appropriate
algorithms and closed loop feedback control, the microcontroller 44
is able to monitor and anticipate drift and changes in the
simulated output signal from the MCM 34. Thus, the microcomputer
output signal changes to produce the desired simulated signal
output voltage to the controller of the existing system 42.
[0069] When the motor is driven CW (CCW), the lumbar support travel
is upward (downward) and the lumbar support position sensor output
voltage is also going upward (downward). The motor 24 is
immediately turned off when end of travel is detected, and at this
point only movement in the opposite direction is allowed. Once
movement in the opposite direction is detected, the end of travel
software flag is released and movement in either direction is
allowed. This automatic stopping and reversing of the drive motor
direction at ends of lumbar support travel during lumbar massage
can be annoying to some, so an alternate hardware choice may be
made with appropriate required changes in software algorithms such
as the termination of current before end of travel as discussed
earlier. Such alternate hardware can take the form of a crank gear
with a crankshaft and pushrod mechanism to convert continuous motor
operation into a reciprocating back-and-forth motion.
[0070] The reversal of direction during motor drive in either the
CW or the CCW direction, hence the reversal of the lumbar support
position sensor voltage from upward to downward or from downward to
upward, flags the software within the microcontroller 44 that an
end of travel limit has been reached.
[0071] The massage control module may be either in series, in
parallel, or combinations thereof to intercept and simulate signals
between the existing seat controller and external devices such as:
BATTERY, COMMON, control Switches, position sensor, and motor. A
portion 50 of terminals may be part of the coupling terminals,
although it is preferably eliminated to simplify the housing when
replaced with vehicle wiring harness adaptions.
[0072] With feedback monitoring and appropriate software
algorithms, such as drift control protection, to control the
switched pulsing of transistors Q10 and Q6, the MCM may maintain
control of the output voltage over a range from COMMON to Vcc. The
feedback voltage as read by the microcontroller 44 at input RA1 is
compared with the desired output voltage, the difference affecting
the number of fixed duration pulses necessary at either transistor
Q10 to raise the output voltage or at transistor Q6 to lower the
output voltage. The output voltage is read by the microcontroller
44 which then turns on either transistor Q10 or Q6 in a pulsing
manner to respectively raise or lower the output voltage to the
desired level. When the voltage at the output varies from the
desired output voltage, the microcontroller 44 uses software
algorithms to determine the length of time for the voltage change
and how many pulses occurred to correct the voltage change. In
anticipation of similar drift characteristics, the microcontroller
44 will then pulse either transistor Q10 or transistor Q6 to
maintain the desired output voltage. This algorithm is adaptive and
can be used for static and dynamic output voltages desired to
obtain preferred rates for seat movement.
[0073] As shown in FIGS. 7 and 8, a modified control system
includes an electronic control module 110 used to drive a motor
112. The motor shaft 114 is coupled to a plurality of selectively
engageable mechanical transmissions 116, 118, and 120. Selection of
each transmission being operated by the shaft 114 preferably
includes a solenoid 122 in each of the transmissions 116, 118, and
120. As best shown in FIG. 8, the engagement mechanism operates in
response to the solenoid 122 so that a disengaged solenoid drops a
mating worm drive gear 124 into a rib feature 126 in the
transmission housing 128 to prevent movement when the solenoid 122
is not actuated. Each of the transmissions may be a power take-off
for substantially different displacement mechanisms. Such a system
substantially reduces the number of motors that must be employed in
the seat control system and further simplifies a seat control
assembly with displacers when constructed according to the present
invention. Nevertheless, the electronic control module 110
incorporates the motor operations parameters such as the commutator
pulse counters and the compensation features that enable the
position of the seat element supports that are displaced to be
accurately positioned as desired.
[0074] As a result, the present invention improves the accuracy and
precision of displacer control by relying upon motor movement.
Since detection of movement is physically simplified where external
sensors can be avoided, the preferred embodiment for a rotary motor
employs a commutator pulse detector and a compensator for
monitoring operating parameters that may be used to simulate pulses
when movement detection is obscured. In a linear motor example, the
pulses accounted for control may be the driving pulses delivered to
the motor. Pulses may also be monitored by responses from detecting
non-energized windings. Regardless of the mannor of detection, a
position limiter controls power delivery to the motor for accurate
positioning of a displacer in response to microprocessing
evaluation and interaction of multiple operating parameters in a
compensator. As a result, previously unreliable detection systems
may be used in a substantially less complex and less costly
displacement mechanism having multiple functions and multiple
memory configurations of the displacers.
[0075] Having thus described embodiments of the present invention,
many modifications will become apparent to those of ordinary skill
in the art to which it pertains without departing from the scope
and spirit of the present invention as defined in the appended
claims.
* * * * *