The Control System Design Of Hind Leg Of Stair Climbing Wheelchair

As the quality of life improved gradually,it’s a top priority to provide a convenient transport for the elderly and limb disabled.Electric wheelchair is one of the ideal choices.However,with the rise of steps in our surrounding environment,ordinary wheelchair limits the scope of their life and activity space inevitably because it doesn’t have the ability to climb stairs or climb over obstacles.To solve this problem,this project’s main task is to develop a control system of stair climbing wheelchair which can climb up and down the stairs and climb over obstacles automatically.It’s certain that this project makes up for the inadequacy of ordinary wheelchair effectively.As an important part of stair climbing wheelchair,hind leg is also the main research object of this project.First of all,we analyzed the motion state of hind leg in the process of climbing.In the meanwhile,we confirmed the relationship between each parameter and then designed a control system program for the back leg.Secondly,we introduced the design of hardware and the development of software in this hind leg control system.The core master controller is two single chip microcomputers which called STC12C5A60S2,and the auxiliary hardware equipment including sensor detection module and stepper motor drive module is the relay board in the development.Software development mainly includes digital filtering module and fuzzy control algorithm module.In this article,we emphasized on the synchronization of lifting movement of two screw nuts in hind leg basing on the fuzzy control algorithm.At the same time,we conducted the emulation proof through the Simulink in Matlab.Finally,we set up a working interface of back leg based on VC and realized the multicomputer communication through upper machine and lower machine.The interface transmits working instructions to the two pieces of single chip microcomputer.When they accepted the instructions,one single chip microcomputer began to enter into the posture adjust program module,the other entered into the lead screw nut lifting program module of auxiliary adjusting posture.Then they would send the collected angle of the crank and hind leg to the upper computer,and it would show on the working interface of hind leg.