1. Introduction

The manipulator is an automatic device that imitates human hand movements and realizes automatic grasping, carrying, and operating according to given procedures, trajectories, and requirements. It replaces human work especially in the harsh environment of high temperature, high pressure, dusty, flammable, explosive, radioactive, etc., as well as bulky, monotonous, and frequent operation, so it has been widely used.

Industrial manipulator is a high-tech automated production equipment developed in recent decades. Industrial manipulators are an important branch of industrial robots. The characteristic of this product is that it can be programmed to complete all kinds of expected tasks, combining the advantages of man and machine in construction and performance, especially reflecting the human intelligence and adaptability.

2. Technical requirements

The handling manipulator consists of PLC, human-machine interface, servo system, etc.

As the carrier of the core program, PLC is responsible for the control of the transmission of the pulse signal and the processing of various feedback signals to control the operation and coordination of the implementing agencies.

The man-machine interface uses a touch screen, which is convenient for the operator to set parameters and monitor the running status of the entire equipment, and is responsible for man-machine dialogue and communication.

The servo system is composed of the drive, servo motor, and code wheel feedback signals. As the main motion mechanism, the main task is to complete the restraint of the positioning accuracy, execute the pulse signal instructions from the PLC, and at the same time, ensure the stability and rapid response of the motion. The performance directly reflects the overall performance and quality of the handling robot.

Because of the precise positioning of the work piece and the stacking of the work piece, in the robot control, in addition to the vertical arm control, it also involves servo control of the horizontal arm and the waist rotation of the robot. During the transportation process, the servo positioning operation is required to be smooth and smooth. The running speed of the servo will determine whether the working efficiency of the manipulator can meet the customer's application requirements. The servo motor must not overshoot, oscillate, and set for too long during high-speed positioning.

3. System construction

The system is composed of five sets of servo drives and servo motors (the robot transmission system uses belt transmission, and the rigidity is relatively small). It is responsible for the loading and unloading of the machine tool. The 1, 2, 3, and 4 axes control the movements in the x and y directions. 5- axis control of the movement of the z-axis horizontal pallet, the control method adopts the new generation M2 bus system with the mountain iK series driver, the default M2 communication method of the iK series servo driver is Yaskawa mode, and the scene diagram is as follows:

The host computer is connected to the servo drive control terminal, and the control mode is pulse + direction in position mode. The driver and related computing boards are fixed in the electric cabinet, and the servo driver receives the pulse command of the host computer to drive the motor to complete the corresponding action.

4. Application and debugging of Zhishan servo in the handling robot

1. Servo drive and motor configuration

2. Related parameter settings

The transmission system of the manipulator adopts belt transmission, and the rigidity is relatively soft. When the gain is high, the system may easily cause oscillation. The handling process requires the servo to be stable and fast, and no overshoot and jitter can occur. Therefore, in the process of debugging, to ensure that the system does not cause system oscillation, try to increase the speed loop proportional gain. The speed loop integral gain and position loop proportional gain should be reduced to prevent overshoot when the transverse axis stops.

Zhishan Intelligent Control iK series bus-type servos ensure the fast and stable operation of the handling manipulator with its stable and fast ability.

5. Mechatrolink

It is an open field network, first developed by Yaskawa Electric and later maintained by Mechatrolink Association. Mechatrolink can realize a controller to interact with multiple slave devices at the same time. Reliable high-speed communication and data synchronization kinetic energy can improve the response speed of the system and promote the development and implementation of advanced functions. It uses a simple cable connection to simplify the system and facilitate system expansion.

(1) Realize high speed and high precision control

M2 can connect up to 30 stations, the minimum distance between stations 50cm, the maximum transmission distance of 50m (repeaters may be extended to 100m), the transmission rate of 10Mbps, a minimum transmission cycle of 250 [mu] S;

The control mode can be switched freely in the online state;

It can realize the functions of synchronization and interpolation between axes, and easily cope with the mechanical movements with complex control requirements.

(2) Reduce costs

Through the network, only the communication cable can complete the connection between the controller and the I / O device or servo drive;

Significantly reduce wiring inspection work and reduce the man-hours required to build the system.

(3) Improve maintainability

Set and manage the parameters of each slave station through the master station computer;

The slave machine can be replaced while online.