Design Of Embedded Control System Of Hanging-basket-type High-low Temperature Shock Test Chamber

With the rapid development of science and technology, new requirements and standards are continuously being put forward for the reliability of the product in various industries. Therefore, with the improvement of testing standards, environmental test equipment, the important tool of product reliability testing, its performance requirements are also higher and higher. Especially the performance of equipment control system, a number of technical indexes are closely related. But the control system of domestic environmental testing equipment depends on general industrial control system, which makes the development of the equipment of the environmental testing technology at home is a big barrier.This topic comes to internal project. The basket type thermal shock box as test object is the research object in this paper, which is one of the environmental test equipment. For using the embedded technology, research and development of an environmental test equipment’s controller which can reach the international level. At the same time to improve the price ratio of control and establish a control system with the characteristics of the factory. In this paper, the main content of the design is as follows:Through the analysis of working principle of basket type thermal shock box and its existing technical index, pointing out the technology index which is associated with the control system and proposed improvement plan. The relevant technical indicators include temperature deviation, temperature fluctuation, temperature fluctuation, etc.Hardware design of the embedded controller, and the control module.Firstly, the hardware frame is designed, according to the control requirement, the hardware configuration is put forward and the main chip is selected. The controller is the man-machine interface and the main algorithm processing platform, and its main processing area need to have the ultra-high data processing ability. Measurement and control module is the sensor device data acquisition terminal and various 10 control hardware platform and so there is a need for multiple sensor inputs and IO resources.The optimization design of refrigeration system. By analyzing the shortcomings of the old cascade refrigeration system, the disadvantages of the thermal expansion valve as the energy saving structure are pointed out, which Including slow response, low degree of automation, low efficiency of condensation evaporator, etc. Then The advantages of digital control and high accuracy of electronic expansion valve are presented, which can be used in improving the degree of automation and maximizing the efficiency of the refrigeration system.The realization of the main software of the embedded touch controller and measurement and control module. According to actual needs, Linux is used as the controller’s embedded system, and the realization of the man-machine interface and the soft PLC is studied, the adaptive PID algorithm is analyzed. uC/OS-II is used as the measurement and control module’s embedded system, and the anti-pulse means digital filter algorithm and the electronic expansion valve control method are the main software of this system.Technical indicators verification.According to the environmental testing standards, the appropriate tool for the optimization of the equipment for verification of indicators.