Control system of AGV unmanned guided vehicle

The AGV unmanned guided vehicle control system is similar to the robot controller, which is used to monitor the AGV unmanned guided vehicle. The controller computer receives instructions from the ground station through the communication system and reports its status. Usually the controller can complete the following tasks: manual control, safety device activation, battery status, steering limit, brake release, walking lights, drive and steering motor control and charging contactors, etc. Some AGV unmanned guided vehicles have the ability to program, allowing the trolley to leave the guidance path, drive to a certain teaching location, and return to the guidance path after completing the task.

The control instructions of the AGV unmanned guided vehicle are generally issued by the ground controller, and the status of the AGV unmanned guided vehicle is also sent back to the ground controller through the communication system. There are two communication systems: continuous and decentralized.

The continuous communication system allows the AGV unmanned guided vehicle to use radio frequency methods or use the communication cable in the guide path to send and receive information at any time and at any position relative to the ground controller. Such as the use of radio and infrared laser communication methods. The distributed system only provides communication between a specific AGV and the ground controller at a predetermined location (communication point) such as an AGV docking station. Generally speaking, this kind of communication is realized by inductive or optical methods.

One obvious disadvantage of decentralized communication is that if the AGV unmanned guided vehicle fails between two communication points, the AGV will not be able to contact the ground control station. At present, most AGV systems use decentralized communication methods because of their lower prices.

The safety system of the AGV unmanned guided vehicle must not only protect the AGV, but also protect people or other ground equipment. The safety protection methods can be classified into two categories: contact and non-contact protection systems. For the free path (no fixed guiding path) type of AGV, the vehicle body position calculation is also performed, which is completed by the vehicle body position calculation subsystem. The orientation of the AGV unmanned guided vehicle, that is, the position and direction in the overall coordinate system, has a certain relationship with the movement of the left and right wheels of the vehicle body, and the orientation of the AGV unmanned guided vehicle can be calculated. The function of this subsystem is to calculate the vehicle body position [x(t), y(t) and θ(t)] in real time through integral operation based on sampling information. According to need, the calculated position information is transmitted to the on-board controller through serial communication, and then transmitted to the ground monitoring system through radio communication to realize the monitoring of the AGV unmanned transport vehicle. The ground monitoring system can also operate the vehicle body position calculation subsystem through this communication channel, such as initializing and resetting the vehicle body position to eliminate accumulated errors. The basic input data for completing the calculation of the vehicle body position is the distance of the wheel forward or backward, which is obtained by periodically sampling the rotation angle of the motor driving the wheel.