U.S. patent application number 14/457440 was filed with the patent office on 2016-02-18 for automated guided cart system control.
The applicant listed for this patent is GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to Paul H. Vavrick.
Application Number | 20160048130 14/457440 |
Document ID | / |
Family ID | 55235094 |
Filed Date | 2016-02-18 |
United States Patent
Application |
20160048130 |
Kind Code |
A1 |
Vavrick; Paul H. |
February 18, 2016 |
AUTOMATED GUIDED CART SYSTEM CONTROL
Abstract
A method of operating an automated guided cart may include
directing, using a controller, the cart on a production operation
path; automatically detecting a state-of-charge in an on-board
battery pack; signaling to a remote station the state-of-charge;
and when the state-of-charge is below a predetermined charge limit,
the remote station automatically signaling the cart to
automatically veer from the production operation path to a low
battery charge path and stop at a battery station.
Inventors: |
Vavrick; Paul H.; (Rochester
Hills, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM GLOBAL TECHNOLOGY OPERATIONS LLC |
DETROIT |
MI |
US |
|
|
Family ID: |
55235094 |
Appl. No.: |
14/457440 |
Filed: |
August 12, 2014 |
Current U.S.
Class: |
180/168 |
Current CPC
Class: |
B60L 58/12 20190201;
Y02T 90/14 20130101; G05D 1/0217 20130101; G05B 2219/24136
20130101; G05B 19/41895 20130101; G05B 2219/50393 20130101; Y02T
10/7072 20130101; Y02T 90/12 20130101; G05D 2201/0216 20130101;
Y02T 10/70 20130101; B60L 53/80 20190201; G05D 1/0225 20130101 |
International
Class: |
G05D 1/02 20060101
G05D001/02; B60L 11/18 20060101 B60L011/18; G05B 19/418 20060101
G05B019/418 |
Claims
1. A method of operating an automated guided cart, the method
comprising the steps of: (a) directing, using a controller, the
cart on a production operation path; (b) automatically detecting a
state-of-charge in an on-board battery pack; (c) signaling to a
remote station the state-of-charge; and (d) when the
state-of-charge is below a predetermined charge limit, the remote
station automatically signaling the cart to automatically veer from
the production operation path to a low battery charge path and stop
at a battery station.
2. The method of claim 1 further comprising: (e) when the cart
arrives at the battery station, activating a battery change
indicator.
3. The method of claim 2 further comprising: (e) swapping the
on-board battery pack for a spare battery pack at the battery
station, and (f) activating the cart to return to the production
operation path.
4. The method of claim 1 further comprising: (e) swapping the
on-board battery pack for a spare battery pack at the battery
station, and (f) activating the cart to return to the production
operation path.
5. The method of claim 1 wherein step (a) is further defined by the
controller being located on-board of the cart.
6. The method of claim 1 wherein step (b) is further defined by the
state-of-charge of the battery pack being determined on-board the
cart.
7. The method of claim 1 wherein step (c) is further defined by a
transceiver on the cart communicating with a stationary transceiver
in communication with the remote station.
8. The method of claim 7 wherein step (c) is further defined by the
communication between the transceivers being via infrared
transmissions.
9. The method of claim 7 wherein step (c) is further defined by the
communication between the transceivers being via radio wave
transmissions.
10. A method of operating an automated guided cart, the method
comprising the steps of: (a) directing, using a controller, the
cart on a production operation path; (b) automatically detecting a
state-of-charge in an on-board battery pack; (c) wirelessly
signaling to a remote station the state-of-charge; (d) when the
state-of-charge is below a predetermined charge limit, the remote
station automatically signaling the cart to automatically veer from
the production operation path to a low battery charge path and stop
at a battery station; (e) swapping the on-board battery pack for a
spare battery pack at the battery station; and (f) activating the
cart to return to the production operation path.
11. The method of claim 10 wherein step (c) is further defined by
the communication between the transceivers being via infrared
transmissions.
12. The method of claim 10 further comprising: (e) when the cart
arrives at the battery station, activating a battery change
indicator.
13. (canceled)
14. (canceled)
15. (canceled)
16. (canceled)
Description
BACKGROUND OF INVENTION
[0001] The present invention relates generally to automated guided
cart systems, and more particularly to control of such systems.
[0002] Automated guided carts may be employed in factories to move
items from one location to another. These carts operate
autonomously without a human operator driving the cart. Such carts
may use batteries to power an electric motor to propel the cart.
However, in such operating conditions, there may be times when the
batteries of a particular cart are discharged during use, thus
stranding the cart. This may result in lost production at the
factory. Some attempts at solutions to this concern, for example
buying more expensive equipment/batteries or employing automatic
charging pads, may be more expensive than desired.
SUMMARY OF INVENTION
[0003] An embodiment contemplates a method of operating an
automated guided cart that includes: directing, using a controller,
the cart on a production operation path; automatically detecting a
state-of-charge in an on-board battery pack; signaling to a remote
station the state-of-charge; and when the state-of-charge is below
a predetermined charge limit, the remote station automatically
signaling the cart to automatically veer from the production
operation path to a low battery charge path and stop at a battery
station.
[0004] An embodiment contemplates an automated guide cart system
including: an automated guided cart including an on-board battery
pack, an on-board controller that directs the cart on a production
operation path and automatically detects a state-of-charge in the
on-board battery pack, and an on-board transceiver to transmit a
signal relating to a state-of-charge of the on-board battery pack;
a stationary remote station having a stationary transceiver to
communicate with the on-board transceiver, and a controller to
direct the cart, via a signal from the stationary transceiver, to
continue on the production operation path or to steer onto a low
battery charge path when the state-of-charge of the battery is
below a predetermined threshold.
[0005] An advantage of an embodiment is that automated guide carts,
during normal operation, may be automatically routed offline for
battery replacement when low battery charge is detected. This may
help reduce or eliminate downtime of such carts due to discharged
batteries. Also, the cart is moved to a location that allows for
quick battery replacement.
BRIEF DESCRIPTION OF DRAWINGS
[0006] FIG. 1 is a schematic of an automated guided cart system and
control in a factory.
[0007] FIG. 2 is a schematic figure of a remote station employed
with an automated guided cart system.
DETAILED DESCRIPTION
[0008] Referring to FIG. 1, an automated guide cart system 8
includes an automated guided cart 10 that is shown on a factory
floor 12. The cart 10 may include a battery pack 14 that powers an
electric motor 16, which drives wheels 18, and an automated
steering assembly 20 that steers another set of wheels 22. The cart
10 may also include a controller 24 that is in communication with
the steering assembly 20, battery pack 14 and motor 16. The
controller 24 may be in communication with a battery charge
detector 25, which can detect the state-of-charge of the battery
pack 14. The detector 25 may any one of a number of devices that
can detect the state-of-charge of a battery, as are known to those
skilled in the art. The cart 10 may also include an on-board
transceiver 26 for communication between the controller 24 and a
remote station 28 mounted at a location on the floor 12.
[0009] The remote station 28 may include a power supply 30, which
may be the electrical power supply in the factory, and a controller
32, which is in communication with a transceiver 34 that
communicates with the on-board transceiver 26. The transceivers 26,
34 may communicate with each other, by transmitting data by, for
example, infrared or radio transmission, as the two transceivers
26, 34 pass close to one another along a guide path 36 that the
cart 10 follows.
[0010] The guide path 36 may be, for example, a magnetic tape that
is secured to the floor 12. The guide path 36 is the path along
which the cart 10 travels while conducting production operations to
deliver parts (or other activities) around the factory floor 12. At
a location on the floor 12, the guide path 36 may fork into
continuing on a production operation path 38, where the cart 10
continues on the path to deliver parts, assemblies, etc. associated
with regular duties in the plant, or a low battery charge path 40,
which directs the cart 10 to a battery station 42.
[0011] The battery station 42 may include one or more spare battery
packs 44, and may include a battery charger 46. If this location
includes the battery charger 46, it may be used to charge the spare
battery packs 44 and/or the battery pack 14 on the vehicle, as the
particular situation may warrant. The battery station 42 may also
include some type of battery change indicator 48 that can be used
to notify a factory worker that the cart 10 is at the station 42
and needs a battery change or recharge.
[0012] FIG. 2 illustrates an example of how the remote station 28
may be configured. The power supply 30 may include a neutral line
52 and a one hundred twenty volt supply line 54, with a circuit
breaker 56, the supply line supplying power to a power supply
converter 58. The power supply converter 58 may convert the power
to, for example, twenty four volts, with a power line 60 and a
common line 62. The controller 32 may have various inputs--for
example, there may be a power input 64 and an input 66 from the
transceiver 34. The controller 32 may also have outputs 68. One
output 70 may be a normal condition output that outputs a high
signal when the battery condition is sufficiently charged. Another
output 72 may be a battery low condition output that outputs a high
signal when a low battery charge is reported.
[0013] The operation of the automated guide cart system 8 will now
be described with reference to FIGS. 1 and 2. As the cart 10
travels around the factory floor 12 along the guide path 36, moving
parts or performing other automated operations, the on-board
controller 24 monitors the state-of-charge of the on-board battery
pack 14. As the cart 10 passes the transceiver 34 of the remote
station 28, if the battery pack charge is low, the on-board
transceiver 26 will signal the low charge state, via the stationary
transceiver 34, to the remote station 28. The output of the
controller 32 will signal, via transceiver 34, for the controller
24 to either continue to steer the cart 10 along the production
operation path 38, if the battery charge is adequate, or steer the
cart 10 onto the low battery charge path 40, if the charge of the
on-board battery pack 14 is low. This, in effect, acts similar to
an automated railroad switch to switch along which path the cart 10
will travel, without needed any human intervention. On the low
battery charge path 40, the cart 10 will then pull alongside the
battery station 42 for replacement of the battery pack 14 with a
charged spare battery pack 44. The battery charge indicator 48, if
there is one, may be activated in order to alert a factory worker
that a battery change is needed. Or, the battery station 42 may be
located on the factory floor 12 close to a work station so that a
worker close by will naturally notice when a cart 10 pulls into the
station due to a low battery charge. The battery pack 14 may then
be swapped out for the spare battery pack 44, and the cart 10
activated to return to the production operation path 38 to continue
with its operations on the factory floor 12.
[0014] How low the battery pack charge is before the cart 10 is
directed to the battery station depends upon the particular
situation in which the cart is used and the battery packs being
used. Thus, a predetermined charge limit threshold for low battery
charge can be empirically determined.
[0015] While certain embodiments of the present invention have been
described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention as defined by the
following claims.
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