One-Dimensional Constant Force Device And Control System Face To Robot Grinding

With the advancement of strategic about "made in China 2025",the application of Industrial Robots have a rapidly development in all works of life, bring a new driving force for the manufacturing.Polishing parts of products is a difficulty in the application of Industrial Robots. On the basis of the position trajectory control, we need to make a effective control in contact stresses generated during actual polishing process with Industrial Robots, to meet the need of polishing. Based on the principles and methods of passive submissive, this paper proposes a control method about one-dimensional constant force device, used in rotbot’s polishing.Firstly, for the problem about compliant control of contract stress generated during actual polishing process with Polished Robots, we have analysed two types of related control method and apparatus.Secondly, the design scheme, which use Voice Coil Motor as a power output of the one-dimensional constant force device had mentioned and we had ananlysed principle of the device. Besides, we have created motor closed loop force feedback control system in Force Sensor, to make sure polished contact force is maintained at a relatively constant within the range, according to adjusting the motor current dynamically.Thirdly, we design the softward and hardward of he one-dimensional constant force device. In respect of hardware, we design mechanical structure、the hardware framework of control system、overall circuit arrangement and choose the STM32 to be MCU of the control circuit. According to the characteristics of STM32, we design communication circuit with sensor data collection circuit with PCF8591 and attitude detection circuit. In respect of software, we have come up with the idea about using μcos-Ⅲ embedded real-time operating system in Software Hierarchy. Meanwhile,we design and analyse Discrete PID controller in the control system. At the same time,we have eliminating the defects about the three-axis gyroscope cumulate errors and the slow response speed in gravity acceleration sensor by improving gestures acquired from gravity acceleration sensor and three-axis gyroscope attitude sensor in constant force device,with complementary filtering algorithm.At last, we design experiments to test the one-dimensional constant force device. In order to calibrate the device, we collect datas under different loading corresponding to the output voltage through experiments, which acquire the relation between forces and voltage by least squares fitting. Then, we test the dynamic response characteristics of the device. we input a square wave signal and observe the output of constant force device. The experiments’s result acquire average response time of 53.6ms according to the device’s force following output、the average maximum overshoot is 11.15% of the amplitude of accommodation. As data showed, the dynamic performance is good. Finally, we made a polished experiment with the device, which measure the absolute value of the deviation remains within the 2N and peak of it is 5N. All of the experiments result in a relatively smooth and uniform on the parts of polished surface, which prove the device can make a good effect on polish.