U.S. patent application number 13/780278 was filed with the patent office on 2014-08-28 for systems and vehicles for determining an operational status of at least one trailer brake.
This patent application is currently assigned to Toyota Motor Engineering & Manufacturing North America, Inc.. The applicant listed for this patent is Toyota Motor Engineering & North America, Inc.. Invention is credited to Nicholas Scott Sitarski.
Application Number | 20140244102 13/780278 |
Document ID | / |
Family ID | 51358662 |
Filed Date | 2014-08-28 |
United States Patent
Application |
20140244102 |
Kind Code |
A1 |
Sitarski; Nicholas Scott |
August 28, 2014 |
SYSTEMS AND VEHICLES FOR DETERMINING AN OPERATIONAL STATUS OF AT
LEAST ONE TRAILER BRAKE
Abstract
Systems and vehicles for determining an operational status of at
least one trailer brake are provided. A system for determining an
operational status of at least one trailer brake includes machine
readable instructions stored in one or more memory modules that,
when executed by one or more processors, cause the system to
command a trailer brake current output circuit to intermittently
supply a diagnostic current to the at least one trailer brake
during a trailer brake activation period, receive a sensed current
signal from a trailer brake current sensing circuit in response to
the command to supply the diagnostic current, and determine the
operational status of the at least one trailer brake based on the
sensed current signal.
Inventors: |
Sitarski; Nicholas Scott;
(Ypsilanti, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
North America, Inc.; Toyota Motor Engineering & |
|
|
US |
|
|
Assignee: |
Toyota Motor Engineering &
Manufacturing North America, Inc.
Erlanger
KY
|
Family ID: |
51358662 |
Appl. No.: |
13/780278 |
Filed: |
February 28, 2013 |
Current U.S.
Class: |
701/32.8 |
Current CPC
Class: |
B60T 2270/406 20130101;
B60T 8/1708 20130101; B60T 13/741 20130101; B60T 8/885
20130101 |
Class at
Publication: |
701/32.8 |
International
Class: |
B60T 17/22 20060101
B60T017/22 |
Claims
1. A system for determining an operational status of at least one
trailer brake comprising: one or more processors; one or more
memory modules communicatively coupled to the one or more
processors; a trailer brake current output circuit electrically
coupled to the at least one trailer brake and communicatively
coupled to the one or more processors; a trailer brake current
sensing circuit electrically coupled to the at least one trailer
brake and communicatively coupled to the one or more processors; a
trailer brake activation input circuit communicatively coupled to
the one or more processors; machine readable instructions stored in
the one or more memory modules that cause the system to perform at
least the following when executed by the one or more processors:
command the trailer brake current output circuit to intermittently
supply a diagnostic current to the at least one trailer brake
during a trailer brake activation period and during a
non-activation period, wherein a trailer brake activation signal is
received from the trailer brake activation input circuit during the
trailer brake activation period; receive a sensed current signal
from the trailer brake current sensing circuit in response to the
command to supply the diagnostic current; and determine the
operational status of the at least one trailer brake based on the
sensed current signal.
2. The system of claim 1, wherein the machine readable instructions
stored in the one or more memory modules that cause the system to
command the trailer brake current output circuit to intermittently
supply the diagnostic current to the at least one trailer brake
cause the system to: provide a pulse-width-modulated diagnostic
current command signal to the trailer brake current output circuit,
wherein the trailer brake current output circuit supplies the
diagnostic current to the at least one trailer brake based on the
pulse-width modulated diagnostic current command signal.
3. The system of claim 2, further comprising a diagnostic current
command conductor and an activation current command conductor,
wherein the diagnostic command is provided by the diagnostic
current command conductor and the activation current command is
provided by the activation current command conductor.
4. The system of claim 2, wherein the machine readable instructions
stored in the one or more memory modules further cause the system
to: provide a pulse-width-modulated brake activation current
command signal to the trailer brake current output circuit in
response to receiving the trailer brake activation signal from the
trailer brake activation input circuit, wherein the trailer brake
current output circuit supplies a brake activation current to the
at least one trailer brake based on the pulse-width modulated brake
activation current command signal, wherein the pulse-width
modulated brake activation current command signal has a first
voltage level and a first frequency, wherein the pulse-width
modulated diagnostic current command signal has a second voltage
level and a second frequency, and wherein the first voltage level
is greater than the second voltage level and the second frequency
is greater than the first frequency.
5. The system of claim 4, wherein the machine readable instructions
stored in the one or more memory modules that cause the system to
determine the operational status of the at least one trailer brake
based on the sensed current signal cause the system to: determine
that the at least one trailer brake is unconnected from the system
when the sensed current signal is indicative of a sensed current
below a connection threshold.
6. The system of claim 4, wherein the machine readable instructions
stored in the one or more memory modules that cause the system to
determine the operational status of the at least one trailer brake
based on the sensed current signal cause the system to: determine
that a short circuit condition exists when the sensed current
signal is indicative of a sensed current above a short circuit
threshold.
7. The system of claim 1, wherein the machine readable instructions
stored in the one or more memory modules that cause the system to
command the trailer brake current output circuit to intermittently
supply the diagnostic current to the at least one trailer brake
cause the system to: command the trailer brake current output
circuit to intermittently supply the diagnostic current to the at
least one trailer brake at random times.
8. The system of claim 1, wherein the diagnostic current is below
an activation threshold.
9. A system for determining an operational status of at least one
trailer brake comprising: one or more processors; one or more
memory modules communicatively coupled to the one or more
processors; a trailer brake current output circuit electrically
coupled to the at least one trailer brake and communicatively
coupled to the one or more processors; a trailer brake current
sensing circuit electrically coupled to the at least one trailer
brake and communicatively coupled to the one or more processors; a
trailer brake activation input circuit communicatively coupled to
the one or more processors; machine readable instructions stored in
the one or more memory modules that cause the system to perform at
least the following when executed by the one or more processors:
command the trailer brake current output circuit to intermittently
supply a diagnostic current to the at least one trailer brake
during a trailer brake activation period, wherein a trailer brake
activation signal is received from the trailer brake activation
input circuit during the trailer brake activation period; receive a
sensed current signal from the trailer brake current sensing
circuit in response to the command to supply the diagnostic
current; and determine the operational status of the at least one
trailer brake based on the sensed current signal.
10. The system of claim 9, wherein the machine readable
instructions stored in the one or more memory modules that cause
the system to determine the operational status of the at least one
trailer brake based on the sensed current signal cause the system
to: determine that the at least one trailer brake is unconnected
from the system when the sensed current signal is indicative of a
sensed current below a connection threshold.
11. The system of claim 9, wherein the machine readable
instructions stored in the one or more memory modules that cause
the system to determine the operational status of the at least one
trailer brake based on the sensed current signal cause the system
to: determine that a short circuit condition exists when the sensed
current signal is indicative of a sensed current above a short
circuit threshold.
12. The system of claim 9, wherein the machine readable
instructions stored in the one or more memory modules that cause
the system to command the trailer brake current output circuit to
intermittently supply the diagnostic current to the at least one
trailer brake cause the system to: command the trailer brake
current output circuit to intermittently supply the diagnostic
current to the at least one trailer brake at random times.
13. The system of claim 9, wherein the machine readable
instructions stored in the one or more memory modules that cause
the system to command the trailer brake current output circuit to
intermittently supply the diagnostic current to the at least one
trailer brake cause the system to: provide a pulse-width-modulated
diagnostic current command signal to the trailer brake current
output circuit, wherein the trailer brake current output circuit
supplies the diagnostic current to the at least one trailer brake
based on the pulse-width modulated diagnostic current command
signal.
14. The system of claim 13, wherein the trailer brake current
output circuit includes at least one transistor.
15. The system of claim 13, wherein the machine readable
instructions stored in the one or more memory modules further cause
the system to: provide a pulse-width-modulated brake activation
current command signal to the trailer brake current output circuit
in response to receiving a trailer brake activation signal from the
trailer brake activation input circuit, wherein the trailer brake
current output circuit supplies a brake activation current to the
at least one trailer brake based on the pulse-width modulated brake
activation current command signal, wherein the pulse-width
modulated brake activation current command signal has a first
voltage level and a first frequency, wherein the pulse-width
modulated diagnostic current command signal has a second voltage
level and a second frequency, and wherein the first voltage level
is greater than the second voltage level and the second frequency
is greater than the first frequency.
16. The system of claim 9, wherein the diagnostic current is below
an activation threshold.
17. A vehicle for determining an operational status of at least one
trailer brake of a trailer towed by the vehicle, the vehicle
comprising: one or more processors; one or more memory modules
communicatively coupled to the one or more processors; a trailer
brake current output circuit electrically coupled to the at least
one trailer brake and communicatively coupled to the one or more
processors; a trailer brake current sensing circuit electrically
coupled to the at least one trailer brake and communicatively
coupled to the one or more processors; a trailer brake activation
input circuit communicatively coupled to the one or more
processors; machine readable instructions stored in the one or more
memory modules that cause the vehicle to perform at least the
following when executed by the one or more processors: command the
trailer brake current output circuit to intermittently supply a
diagnostic current to the at least one trailer brake during a
trailer brake activation period and during a non-activation period,
wherein a trailer brake activation signal is received from the
trailer brake activation input circuit during the trailer brake
activation period; receive a sensed current signal from the trailer
brake current sensing circuit in response to the command to supply
the diagnostic current; and determine the operational status of the
at least one trailer brake based on the sensed current signal.
18. The vehicle of claim 17, wherein the machine readable
instructions stored in the one or more memory modules that cause
the vehicle to command the trailer brake current output circuit to
intermittently supply the diagnostic current to the at least one
trailer brake cause the vehicle to: provide a pulse-width-modulated
diagnostic current command signal to the trailer brake current
output circuit, wherein the trailer brake current output circuit
supplies the diagnostic current to the at least one trailer brake
based on the pulse-width modulated diagnostic current command
signal.
19. The vehicle of claim 17, wherein the machine readable
instructions stored in the one or more memory modules further cause
the vehicle to: provide a pulse-width-modulated brake activation
current command signal to the trailer brake current output circuit
in response to receiving the trailer brake activation signal from
the trailer brake activation input circuit, wherein the trailer
brake current output circuit supplies a brake activation current to
the at least one trailer brake based on the pulse-width modulated
brake activation current command signal, wherein the pulse-width
modulated brake activation current command signal has a first
voltage level and a first frequency, wherein the pulse-width
modulated diagnostic current command signal has a second voltage
level and a second frequency, and wherein the first voltage level
is greater than the second voltage level and the second frequency
is greater than the first frequency.
20. The vehicle of claim 17, wherein the machine readable
instructions stored in the one or more memory modules that cause
the vehicle to command the trailer brake current output circuit to
intermittently supply the diagnostic current to the at least one
trailer brake cause the vehicle to: command the trailer brake
current output circuit to intermittently supply the diagnostic
current to the at least one trailer brake at random times.
Description
TECHNICAL FIELD
[0001] The present specification generally relates to systems and
vehicles for trailer brake control and, more specifically, to
systems and vehicles for determining an operational status of at
least one trailer brake.
BACKGROUND
[0002] Trailers (e.g., recreational trailers, utility trailers,
boat trailers, semi-trailers, and the like) may be towed by
vehicles (e.g., automobiles and trucks). Some trailers are provided
with trailer brakes, such as electric trailer brakes. Electric
trailer brakes typically include brake shoes that frictionally
engage a drum when activated. In such systems, an electromagnet is
typically mounted on one end of a lever in order to actuate the
brake shoes. When an electric current is applied to the
electromagnet, the lever is pivoted as the electromagnet is drawn
against the rotating brake drum, thereby actuating the electric
trailer brakes. Electric braking systems include a trailer brake
controller coupled to the towing vehicle that controls the
application of the electric current to the trailer brakes, and
thereby controls trailer braking. It may be desirable to determine
an operational status of trailer brakes to determine whether the
trailer brakes are malfunctioning, whether the trailer brakes are
connected, etc.
[0003] Accordingly, a need exists for systems and vehicles for
determining an operational status of at least one trailer
brake.
SUMMARY
[0004] In one embodiment, a system for determining an operational
status of at least one trailer brake includes one or more
processors, one or more memory modules communicatively coupled to
the one or more processors, a trailer brake current output circuit
electrically coupled to the at least one trailer brake and
communicatively coupled to the one or more processors, a trailer
brake current sensing circuit electrically coupled to the at least
one trailer brake and communicatively coupled to the one or more
processors, a trailer brake activation input circuit
communicatively coupled to the one or more processors, and machine
readable instructions stored in the one or more memory modules.
When executed by the one or more processors, the machine readable
instructions cause the system to command the trailer brake current
output circuit to intermittently supply a diagnostic current to the
at least one trailer brake during a trailer brake activation period
and during a non-activation period. A trailer brake activation
signal is received from the trailer brake activation input circuit
during the trailer brake activation period. When executed by the
one or more processors, the machine readable instructions further
cause the system to receive a sensed current signal from the
trailer brake current sensing circuit in response to the command to
supply the diagnostic current and determine the operational status
of the at least one trailer brake based on the sensed current
signal.
[0005] In another embodiment, a system for determining an
operational status of at least one trailer brake includes one or
more processors, one or more memory modules communicatively coupled
to the one or more processors, a trailer brake current output
circuit electrically coupled to the at least one trailer brake and
communicatively coupled to the one or more processors, a trailer
brake current sensing circuit electrically coupled to the at least
one trailer brake and communicatively coupled to the one or more
processors, a trailer brake activation input circuit
communicatively coupled to the one or more processors, and machine
readable instructions stored in the one or more memory modules.
When executed by the one or more processors, the machine readable
instructions cause the system to command the trailer brake current
output circuit to intermittently supply a diagnostic current to the
at least one trailer brake during a trailer brake activation
period. A trailer brake activation signal is received from the
trailer brake activation input circuit during the trailer brake
activation period. When executed by the one or more processors, the
machine readable instructions further cause the system to receive a
sensed current signal from the trailer brake current sensing
circuit in response to the command to supply the diagnostic current
and determine the operational status of the at least one trailer
brake based on the sensed current signal.
[0006] In yet another embodiment, a vehicle for determining an
operational status of at least one trailer brake includes one or
more processors, one or more memory modules communicatively coupled
to the one or more processors, a trailer brake current output
circuit electrically coupled to the at least one trailer brake and
communicatively coupled to the one or more processors, a trailer
brake current sensing circuit electrically coupled to the at least
one trailer brake and communicatively coupled to the one or more
processors, a trailer brake activation input circuit
communicatively coupled to the one or more processors, and machine
readable instructions stored in the one or more memory modules.
When executed by the one or more processors, the machine readable
instructions cause the vehicle to command the trailer brake current
output circuit to intermittently supply a diagnostic current to the
at least one trailer brake during a trailer brake activation period
and during a non-activation period. A trailer brake activation
signal is received from the trailer brake activation input circuit
during the trailer brake activation period. When executed by the
one or more processors, the machine readable instructions further
cause the vehicle to receive a sensed current signal from the
trailer brake current sensing circuit in response to the command to
supply the diagnostic current and determine the operational status
of the at least one trailer brake based on the sensed current
signal.
[0007] These and additional features provided by the embodiments of
the present disclosure will be more fully understood in view of the
following detailed description, in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The embodiments set forth in the drawings are illustrative
and exemplary in nature and not intended to limit the disclosure.
The following detailed description of the illustrative embodiments
can be understood when read in conjunction with the following
drawings, where like structure is indicated with like reference
numerals and in which:
[0009] FIG. 1 schematically depicts a vehicle including a system
for determining an operational status of at least one trailer brake
of a trailer connected to the vehicle, according to one or more
embodiments shown and described herein; and
[0010] FIG. 2 schematically depicts a flowchart for determining an
operational status of at least one trailer brake, according to one
or more embodiments shown and described herein.
DETAILED DESCRIPTION
[0011] The embodiments disclosed herein include systems and
vehicles for determining an operational status of at least one
trailer brake. Referring generally to FIGS. 1 and 2, a system for
determining an operational status of a trailer brake may include a
processor, a memory module, a trailer brake current output circuit,
a trailer brake current sensing circuit, a trailer brake activation
input circuit, and machine readable instructions stored in the
memory module. The machine readable instructions may cause the
system to command the trailer brake current output circuit to
intermittently supply a diagnostic current to the trailer brake
during a trailer brake activation period, receive a sensed current
signal from the trailer brake current sensing circuit in response
to the command to supply the diagnostic current, and determine the
operational status of the trailer brake based on the sensed current
signal. By supplying the diagnostic current during a trailer brake
activation period, additional operational status information
pertaining to the at least one trailer brake may be able to be
determined during the trailer brake activation period, which may be
utilized for a number of purposes. The various systems and vehicles
for determining an operational status of at least one trailer brake
will be described in more detail herein with specific reference to
the corresponding drawings.
[0012] Referring now to FIG. 1, an embodiment of an exemplary
vehicle 100 including an exemplary system 110 for determining an
operational status of at least one trailer brake 152 of a trailer
150 connected to the vehicle 100 is schematically depicted. The
vehicle 100 may be an automobile or any other passenger or
non-passenger vehicle such as, for example, a tractor or a tractor
truck. The trailer 150 may be any unpowered vehicle including one
or more wheels capable of being pulled by the vehicle 100 such as,
for example, a recreational trailer, a utility trailer, a boat
trailer, a semi-trailer, and the like. As depicted in FIG. 1, the
trailer 150 includes two trailer brakes 152, one coupled to each
wheel of the front axle. However, it should be understood that in
other embodiments, the trailer 150 may include more than or less
than two trailer brakes 152, such as in embodiments in which the
trailer 150 includes multiple axles with one or more trailer brakes
152 associated with each axle.
[0013] The system 110 for determining the operational status of at
least one trailer brake 152 includes a communication path 111, one
or more processors 112, one or more memory modules 114, a trailer
brake activation input circuit 116, a trailer brake current output
circuit 118, a trailer brake current sensing circuit 120, an
optional display 122, and an optional speaker 124. The various
components of the system 110 and the interaction thereof will be
described in detail below.
[0014] The communication path 111 may be formed from any medium
that is capable of transmitting a signal such as, for example,
conductive wires, conductive traces, optical waveguides, or the
like. Moreover, the communication path 111 may be formed from a
combination of mediums capable of transmitting signals. In one
embodiment, the communication path 111 comprises a combination of
conductive traces, conductive wires, connectors, and buses that
cooperate to permit the transmission of electrical data signals to
components such as processors, memories, sensors, input devices,
output devices, and communication devices. Accordingly, the
communication path 111 may comprise a vehicle bus, such as for
example a LIN bus, a CAN bus, a VAN bus, and the like.
Additionally, it is noted that the term "signal" means a waveform
(e.g., electrical, optical, magnetic, mechanical or
electromagnetic), such as DC, AC, sinusoidal-wave, triangular-wave,
square-wave, vibration, and the like, capable of traveling through
a medium. The communication path 111 communicatively couples the
various components of the system 110. As used herein, the term
"communicatively coupled" means that coupled components are capable
of exchanging data signals with one another such as, for example,
electrical signals via conductive medium, electromagnetic signals
via air, optical signals via optical waveguides, and the like.
[0015] Each of the one or more processors 112 of the system 110 may
be any device capable of executing machine readable instructions.
Accordingly, each of the one or more processors 112 may be a
controller, an integrated circuit, a microchip, a computer, or any
other computing device. The one or more processors 112 are
communicatively coupled to the other components of the system 110
by the communication path 111. Accordingly, the communication path
111 may communicatively couple any number of processors with one
another, and allow the components coupled to the communication path
111 to operate in a distributed computing environment.
Specifically, each of the components may operate as a node that may
send and/or receive data.
[0016] Each of the one or more memory modules 114 of the system 110
is coupled to the communication path 111 and communicatively
coupled to the one or more processors 112. The one or more memory
modules 114 may comprise RAM, ROM, flash memories, hard drives, or
any device capable of storing machine readable instructions such
that the machine readable instructions can be accessed and executed
by the one or more processors 112. The machine readable
instructions may comprise logic or algorithm(s) written in any
programming language of any generation (e.g., 1GL, 2GL, 3GL, 4GL,
or 5GL) such as, for example, machine language that may be directly
executed by the processor, or assembly language, object-oriented
programming (OOP), scripting languages, microcode, etc., that may
be compiled or assembled into machine readable instructions and
stored on the one or more memory modules 114. Alternatively, the
machine readable instructions may be written in a hardware
description language (HDL), such as logic implemented via either a
field-programmable gate array (FPGA) configuration or an
application-specific integrated circuit (ASIC), or their
equivalents. Accordingly, the methods described herein may be
implemented in any conventional computer programming language, as
pre-programmed hardware elements, or as a combination of hardware
and software components.
[0017] Still referring to FIG. 1, the trailer brake activation
input circuit 116 is coupled to the communication path 111 and
communicatively coupled to the one or more processors 112. The
trailer brake activation input circuit 116 provides a trailer brake
activation signal to the one or more processors 112 that may be
processed in order to determine when the at least one trailer brake
152 is to be activated. In some embodiments, the trailer brake
activation input circuit 116 may include one or more sensors and/or
devices for generating a signal which may be utilized by the system
110 in determining whether to activate the at least one trailer
brake 152. For example, in some embodiments, the trailer brake
activation input circuit 116 may include one or more
accelerometers, a vehicle brake pressure sensing circuit, a manual
trailer brake activation input (e.g., a pushbutton, slider switch,
and the like), a vehicle brake light circuit, or combinations
thereof.
[0018] The trailer brake current output circuit 118 is coupled to
the communication path 111 and communicatively coupled to the one
or more processors 112. The trailer brake current output circuit
118 is electrically coupled to the at least one trailer brake 152
by a conductive medium, such as a conductive wire. The trailer
brake current output circuit 118 is controlled by the one or more
processors 112 and supplies current to the at least one trailer
brake 152 via the conductive medium when commanded by the one or
more processors 112. In some embodiments, the trailer brake current
output circuit 118 may supply current from the power system of the
vehicle 100. The trailer brake current output circuit 118 generally
includes one or more electrical components, such as resistors,
capacitors, transistors, inductors, and the like. In some
embodiments, the trailer brake current output circuit 118 may
include at least one power transistor, such as a MOSFET
transistor.
[0019] Still referring to FIG. 1, the exemplary trailer brake
current sensing circuit 120 is coupled to the communication path
111 and communicatively coupled to the one or more processors 112.
The trailer brake current sensing circuit 120 is electrically
coupled to the at least one trailer brake 152 and the trailer brake
current output circuit 118 by a conductive medium, such as a
conductive wire. The trailer brake current sensing circuit 120
senses the current supplied by the trailer brake current output
circuit to the at least one trailer brake 152 and provides the
sensed current to the one or more processors 112. The trailer brake
current sensing circuit 120 generally includes one or more
electrical components, such as resistors, capacitors, transistors,
amplifiers, and the like. For example, in one embodiment, the
trailer brake current sensing circuit 120 may provide an indication
of a voltage drop across a resistor to the one or more processors
112, which may determine the current supplied to the at least one
trailer brake 152 based on the voltage drop.
[0020] Referring still to FIG. 1, the exemplary system 110
comprises a display 122 for providing visual output such as, for
example, information or notifications pertaining to the operational
status of the at least one trailer brake 152. The display 122 is
coupled to the communication path 111 and communicatively coupled
to the one or more processors 112. The display 122 may include any
medium capable of transmitting an optical output such as, for
example, light emitting diodes, a liquid crystal display, a plasma
display, or the like. In some embodiments, the display 122 may
include a combination meter positioned on a dashboard of the
vehicle 100. It is noted that the display 122 can include at least
one of the one or more processors 112 and/or at least one of the
one or memory modules 114. Additionally, it should be understood
that in some embodiments, the system 110 does not include the
display 122, such as in embodiments in which the system 110 does
not provide visual output of information or notifications
pertaining to the operational status of the at least one trailer
brake 152.
[0021] The system 110 depicted in FIG. 1 comprises a speaker 124
for transforming data signals from the system 110 into mechanical
vibrations, such as in order to provide an audible indication of
the operational status of the at least one trailer brake 152. The
speaker 124 is coupled to the communication path 111 and
communicatively coupled to the one or more processors 112. However,
it should be understood that in other embodiments the system 110
may not include the speaker 124, such as in embodiments in which
the system 110 does not provide an audible indication of the
operational status of the at least one trailer brake 152.
[0022] FIG. 2 schematically depicts an exemplary flowchart 200 for
determining an operational status of at least one trailer brake
152. Referring now to FIGS. 1 and 2, in block 202, the machine
readable instructions stored in the one or more memory modules 114,
when executed by the one or more processors 112, cause the system
110 to command the trailer brake current output circuit 118 to
intermittently supply a diagnostic current to the at least one
trailer brake 152. In some embodiments, the system 110 commands the
trailer brake current output circuit 118 to intermittently supply a
diagnostic current to the at least one trailer brake 152 during a
trailer brake activation period. A trailer brake activation period
is a period during which a trailer brake activation signal is
received from the trailer brake activation input circuit 116. In
some embodiments, the system 110 commands the trailer brake current
output circuit 118 to intermittently supply a diagnostic current to
the at least one trailer brake 152 during a trailer brake
activation period and during a non-activation period. A
non-activation period is a period during which a trailer brake
activation signal is not received from the trailer brake activation
input circuit 116. By supplying the diagnostic current during a
trailer brake activation period, additional operational status
information pertaining to the at least one trailer brake 152 may be
able to be determined. Furthermore, by supplying the diagnostic
current during a trailer brake activation period and during a
non-activation period, operational status information pertaining to
the at least one trailer brake 152 may be able to be determined
both during times when the at least one trailer brake 152 is
activated and during times when the at least one trailer brake 152
is not activated. The additional operational status information may
facilitate notification of the operational status of the at least
one trailer brake 152 to be provided to a driver of the vehicle 100
and/or corrective action to be taken when a malfunction is detected
regardless of whether the at least one trailer brake 152 is
activated. In some embodiments, the system 110 commands the trailer
brake current output circuit 118 to intermittently supply a
diagnostic current to the at least one trailer brake 152 at random
times. In such embodiments, the one or more processors 112 may
determine the random times to supply the diagnostic current based
on a random number generator. In other embodiments, the system 110
commands the trailer brake current output circuit 118 to
intermittently supply the diagnostic current to the at least one
trailer brake 152 at regular intervals.
[0023] Still referring to block 202 of FIG. 2 in the context of
FIG. 1, the machine readable instructions stored in the one or more
memory modules 114, when executed by the one or more processors
112, cause the system 110 to command the trailer brake current
output circuit 118 to intermittently supply a diagnostic current to
the at least one trailer brake 152 by providing a
pulse-width-modulated diagnostic current command signal to the
trailer brake current output circuit 118. In such embodiments, the
trailer brake current output circuit 118 supplies the diagnostic
current to the at least one trailer brake 152 in proportion to the
pulse-width modulated diagnostic current command signal. However,
it should be understood that in other embodiments, the diagnostic
current command signal may have a waveform other than a
pulse-width-modulated waveform.
[0024] In some embodiments in which the diagnostic current is
commanded to be supplied by providing a pulse-width-modulated
diagnostic current command signal to the trailer brake current
output circuit 118, the voltage and/or frequency of the
pulse-width-modulated diagnostic current command signal may be
different form the voltage and/or frequency of a pulse-width
modulated brake activation current command signal that is supplied
to the trailer brake current output circuit 118 in response to
receiving the trailer brake activation signal from the trailer
brake activation input circuit. For example, in some embodiments,
the pulse-width modulated brake activation current command signal
has a first voltage level and a first frequency and the pulse-width
modulated diagnostic current command signal has a second voltage
level and a second frequency. The first voltage level may be
greater than the second voltage level, such that the
pulse-width-modulated activation current command signal has a
higher voltage than the pulse-width-modulated diagnostic current
command signal. By way of non-limiting example, the first voltage
level of the pulse-width-modulated activation current command
signal may be about 5 volts and the second voltage level of the
pulse-width-modulated diagnostic current command signal may be
about 1 volt. In some embodiments, the second frequency may be
greater than the first frequency, such that the
pulse-width-modulated diagnostic current command signal has a
higher frequency than the pulse-width-modulated activation current
command signal. In some embodiments, both the frequency and the
voltage of the pulse-width-modulated activation current command
signal and the pulse-width-modulated diagnostic current command
signal may be differ, while in other embodiments only one of the
voltage and frequency may differ.
[0025] In some embodiments, the diagnostic command is provided by a
diagnostic current command conductor and the activation current
command is provided by an activation current command conductor. In
some embodiments, the diagnostic current command conductor and the
activation current command conductor may be separate conductors on
a printed circuit board. In some embodiments, the diagnostic
current command conductor and the activation current command
conductor may be separate conductive wires. In some embodiments,
the diagnostic current command conductor and the activation current
command conductor may be separate output pins of the one or more
processors 112. For example, in some embodiments, the diagnostic
current command may be provide by a first output pin of the one or
more processors 112 and the activation current command may be
provided by a second output pin of the one or more processors 112.
In such embodiments, a diode may connect the first output pin of
the one or more processors 112 to the second output pin of the one
or more processors 112. In embodiments in which the diagnostic
current command and the activation current command are provided by
separate output pins of the one or more processors 112, the
diagnostic current command signal may be provided to the trailer
brake current output circuit 118 during the trailer brake
activation period and the non-activation period (i.e., regardless
of whether the activation current command is provided to the
trailer brake current output circuit 118). By providing a separate
diagnostic current command via a separate output pin of the
processor so that the diagnostic current may be supplied both
during the trailer brake activation period and the non-activation
period in order to obtain additional operational status information
pertaining to the at least one trailer brake 152, the system 110
may be more complicated and/or expensive than if a single output
pin were used to provide both the diagnostic current command during
the non-activation period and the activation current during the
trailer brake activation period.
[0026] The diagnostic current commanded to be supplied in block 202
is generally below an activation threshold, such that if the
diagnostic current is supplied to the at least one trailer brake
152, the at least one trailer brake 152 would not be activated. For
example, in some embodiments in which the at least one trailer
brake 152 includes a brake shoe that is activated by an
electromagnet coupled to a brake shoe that causes the brake shoe to
be drawn against and frictionally engage a brake drum when
sufficient current is supplied to the electromagnet to cause the
brake shoe to engage the drum, the diagnostic current may be below
the activation threshold required to draw the electromagnet to the
drum.
[0027] Still referring to FIGS. 1 and 2, in block 204, the machine
readable instructions stored in the one or more memory modules 114,
when executed by the one or more processors 112, cause the system
110 to receive a sensed current signal from the trailer brake
current sensing circuit 120 in response to the command to supply
the diagnostic current provided in block 202. In some embodiments,
the one or more processors 112 may determine a magnitude of the
sensed current after a predetermined delay has elapsed from the
when the trailer brake current output circuit 118 is commanded to
supply the diagnostic current. In some embodiments, the trailer
brake current sensing circuit 120 may provide an indication of a
voltage drop across a resistor to the one or more processors 112,
which may determine the current supplied to the at least one
trailer brake 152 based on the voltage drop. However, it should be
understood that the trailer brake current sensing circuit 120 may
sense the current in a number of other ways, such as in embodiments
in which the trailer brake current sensing circuit 120 includes one
or more standalone integrated circuits.
[0028] Still referring to FIGS. 1 and 2, in block 206, the machine
readable instructions stored in the one or more memory modules 114,
when executed by the one or more processors 112, cause the system
110 to determine the operational status of the at least one trailer
brake 152 based on the current signal sensed in block 204. By way
of non-limiting example, in some embodiments, the system 110 may
determine that the at least one trailer brake 152 is unconnected
from the system 110 when the sensed current signal is indicative of
a sensed current below a connection threshold. Similarly, in some
embodiments, the system 110 may determine that the at least one
trailer brake 152 is connected to the system 110 based on the
sensed current. As another non-limiting example, in some
embodiments, the system 110 may determine that a short circuit
condition exists when the sensed current signal is indicative of a
sensed current above a short circuit threshold. It should be
understood that the system 110 may determine a variety of other
operational statuses of the at least one trailer brake 152 other
than a short circuit condition or an unconnected status.
[0029] Some embodiments may utilize the operational status of the
at least one trailer brake 152 determined in block 206 to perform
additional tasks. For example, a visual indication of the
operational status may be provided to a driver of the vehicle 100
via the display 122. In some embodiments, the display 122 may
illuminate a connection status indicator based on the determination
that the at least one trailer brake 152 is either connected or
unconnected from the system 110. In some embodiments, the display
122 may illuminate a malfunction indicator (indicating a
malfunction of the at least one trailer brake 152) based on the
determined operational status, such as when a short circuit
condition is detected at block 206. It should be understood that
many other types of information may be provided by the display 122
based on the operational status.
[0030] As another non-limiting example of the system 110 using the
determined operational status for additional tasks, an audible
indication of the operational status of the at least one trailer
brake 152 may be provided by the speaker 124. In some embodiments,
the speaker 124 may provide an audible indication indicative of the
connection status indicator based on the determination that the at
least one trailer brake 152 is either connected or unconnected from
the system 110, such as beeping or emitting a tone when the at
least one trailer brake 152 is connected and/or unconnected from
the system 110. In some embodiments, the speaker 124 may provide an
audible indication indicative of a malfunction of the at least one
trailer brake 152 based on the determined operational status, such
as when a warning sound is emitted when a short circuit condition
is detected at block 206. It should be understood that many other
types of information may be provided by the speaker 124 based on
the operational status.
[0031] It should now be understood that embodiments described
herein provide systems and vehicles for determining an operational
status of at least one trailer brake. By supplying the diagnostic
current during a trailer brake activation period, additional
operational status information pertaining to the at least one
trailer brake may be able to be determined. Furthermore, by
supplying the diagnostic current during a trailer brake activation
period and during a non-activation period, operational status
information pertaining to the at least one trailer brake may be
able to be determined both during times when the at least one
trailer brake is activated and during times when the at least one
trailer brake is not activated, which may thereby facilitate
notification of the operational status of the at least one trailer
brake to be provided to a driver of the vehicle and/or corrective
action to be taken when a malfunction is detected.
[0032] It is noted that the terms "substantially" and "about" may
be utilized herein to represent the inherent degree of uncertainty
that may be attributed to any quantitative comparison, value,
measurement, or other representation. These terms are also utilized
herein to represent the degree by which a quantitative
representation may vary from a stated reference without resulting
in a change in the basic function of the subject matter at
issue.
[0033] While particular embodiments have been illustrated and
described herein, it should be understood that various other
changes and modifications may be made without departing from the
spirit and scope of the claimed subject matter. Moreover, although
various aspects of the claimed subject matter have been described
herein, such aspects need not be utilized in combination. It is
therefore intended that the appended claims cover all such changes
and modifications that are within the scope of the claimed subject
matter.
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