Design And Implementation Of Active Constant Force Device For Industrial Robots

With the arrival of industry 4.0,industrial robots begin to be widely used in all walks of life,which can not only improve the labor productivity but also reduce production costs.Furthermore,they play the important role in reducing the labor intensity of workers,improving the working environment and protecting the safety of workers.The constant force control of industrial robots is the key technique in the polishing industry.The roughness of parts can be reduced and the quality of parts can be improved by using accurate force control.However,in traditional constant force control,both the force and position of robots are necessary to be controlled,which results in the complexity,slow response and low accuracy of industrial robots.In order to solve the above problems,the force control of industrial robot operation can be solved by the independent force control device by separating the force and position of industrial robots.Hence,the position control of the robots is not taken into account in the force control.In this way,the complexity of robots control can be reduced and the accuracy of industrial robots force control can be improved.In this paper,the active constant force device of industrial robots is designed and implemented from the aspects of mechanical structure,mathematical model,hardware and software.Firstly,the working requirements of the constant force device are analyzed and the function of the constant force device is clearly defined.The mechanical structure and the gas structure of the constant force device are designed according to its principle.The scheme of the mechanical structure is proposed to reduce the coupling between different parts and ensure efficient operation of the constant force device.Secondly,the whole structure of the constant force device is analyzed.It is clear that the core of the constant force device model is the piezoelectric proportional valve.The whole system model of the constant force device is obtained by analyzing the working process of the valve and the sensor.The fuzzy PID control is carried out to control the model and the parameters of the control system can be obtained.Thirdly,the hardware and software of the constant force device are designed.The hardware equipment is selected and arranged.The IO of the controller is distributed.The way of the host and lower computer is used by software.Data is exchanged according to the TCP/IP communication protocol.The lower computer is used to control the motion of the constant force device.The host computer is responsible for data monitoring and data updating,so as to achieve the purpose of human-computer interaction.Finally,the UR robot is used to establish the experimental platform of the active constant force device to test the output force of the constant force device in different states.The actual data is monitored in the host computer.The experimental results show that the designed active constant force device can keep the output force constant in various states.It improves the precision control of the industrial robot,reduces the complexity of force of robots,maintains good performance of constant force control in the practical application and has better application value.