A Design Of EPW Controller With Principal And Subordinated Structure

With the social development, the problem of population ageing in our nation is becoming more and more serious. while the citizen's standards of living is improving, the needs of the wheelchair or any other instrument for assistant ambulation from people who are elder and the handicapped whether innately or not are more and more exigent. The electric powered wheelchair is a kind of vehicle which is powered by storage cell and drove by motor. The characteristic of the electric powered wheelchair is easy-handling, stable-steering, non-pollution and low noise. It is an ideal instrument riding instead of walking for the elder and the handicapped which are inconvenience in walking. Until now, the kernel technology of the high-powered electric powered wheelchair and its controller is still in control of foreign countries. But the price of their merchandise is too high for the native customer. So developing a kind of electric powered wheelchair which has the characteristic of high-powered and low cost is an urgent task for the native technological researcher to handle with.This test synthesized the domestic and the overseas development and the research of the electric powered wheelchair, selected the middle drive type in the two-wheel drive type of the wheelchair as the control object of the task. The thesis analyzed the working principles of the DC timing system, investigated the DC motor's numeric control technology and the control strategy. Then the test presented a design scheme of an electric powered controller of the principal and subordinate type structure based on the DSP and MCU. It dwelled on the realization method of the hardware and the software. Combining with the wheelchair's practice running request, it designed a dual-motor coordinated control scheme which based on voltage negative feedback, current positive feedback compensation and unbalanced load compensation. According to the safety request of the electric powered wheelchair, the test designed several schemes corresponding to several possible faults, such as Joystick fault detect, motor fault detect, brake fault detect, MOSFET fault detect, and so on, and presented the practice method. The scheme designed in the thesis separated the power module and the operating and display module of the EPW controller to let it be more stable and safety for the operators and more convenient for the engineers. And the controller also designed a friendly LCD display interface, which is convenient for people to use.The result of the wheelchair's driving experiment proved that the design of the test is feasible and reliable. It caught the original intention of the design.