Controller design of electric wheelchairs Abstract According to the survey, China is currently about 60 million people with disabilities, of which about 8.77 million the number of physically disabled. Chinese elderly aged 60 and above the total population has reached 149 million, accounting for 21.4% of the world's elderly population, ranking first in the world. Makes both the elderly or a congenital or acquired physical disabilities, wheelchair and other assisted walking increasingly urgent demand for tools. The characteristic of the electric powered wheelchair is easy-handing, 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. The 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.