AUTOMATED GUIDED CART SYSTEM CONTROL
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.
The present invention relates generally to automated guided cart systems, and more particularly to control of such systems.
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 INVENTIONAn 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.
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.
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.
Referring to
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.
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.
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.
The operation of the automated guide cart system 8 will now be described with reference to
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.
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.
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)
Type: Application
Filed: Aug 12, 2014
Publication Date: Feb 18, 2016
Inventor: Paul H. Vavrick (Rochester Hills, MI)
Application Number: 14/457,440