Although there are many electric wheelchairs on the market, their basic structure is largely similar: a motor, a motor driver, and a controller. Since a power wheelchair moves on the ground, it does not require the high speed of a normal motor, but it does require a relatively large torque. To reduce the speed and increase the torque of the output shaft, the front end of the motor generally needs to be equipped with a reducer. The general motor is a DC motor with a Hall line number and code plate signal. The Hall signal is used for the commutation of the motor, and the code disc signal feeds back the speed of the motor. Wheelchair users are four-wheel drive solutions. Reliable operation, real-time reading of motor speed and torque, and planning the electric wheelchair to move at a certain speed toward a target point all require a stable and reliable electrical control system.
The following is a list of contents.
There is an operating platform
The motor rotates according to the commands requested by the user
Real-time feedback on the status of the motor
Display of electric wheelchair parameters, such as speed, acceleration, battery capacity, etc.
Safety protection function
There is an operating platform
The electric wheelchair needs to move according to the user's instructions, so the design of the electronic control system needs to consider an interface for inputting instructions to the user. The user's instructions include instructions to set the working mode of the motor, the moving speed of the vehicle, the moving direction of the vehicle, etc.
The motor rotates according to the commands requested by the user
After the user of the electric wheelchair sets the motor speed and other instructions, the controller needs to assign the speed and torque values of each motor through the kinematic equations and dynamics equations according to the instructions input by the user. This part is the key to the entire control system, and it involves how to establish communication between the main controller and each motor drive, as well as the algorithm for the main controller to coordinate the control of each motor.
Real-time feedback on the status of the motor
The main controller of the electric wheelchair controls the movement of the motors through the motor drivers. The main controller also needs to read the status information from the motor feedback in real-time, including the speed and torque of the motor. The main controller reads the feedback speed of each motor and solves the velocity of the vehicle through the inverse kinematic equation. At the same time, the main controller reads the feedback torque values of the motors and records the torque output value of each motor.
Display of electric wheelchair parameters, such as speed, acceleration, battery capacity, etc.
The electric wheelchair moves on a plane. In addition to controlling the movement of the vehicle according to the kinematic and kinetic equations, the electric control system needs to display the speed, acceleration, and battery power of the vehicle in real-time, which can be used for experimental data. At the same time, the display of power can provide users with timely battery charging.
Safety protection function
The electric wheelchair will often encounter some obstacles during the driving process. If not avoided, collisions can damage its structure or connections. The mobile robot needs to detect the distance between the vehicle and the obstacle based on some of its range sensors so that it can avoid the obstacle and perform the next task. At the same time, during the wheel movement, when the wheels are stuck and locked, the current of the electric wheelchair motor will be very high. At this time, the motor needs to be stopped urgently to protect the motor and the battery.
The above is about the basic functions of electric wheelchairs. If you are interested in electric wheelchairs, you can contact us. Our website is www.topmediwheelchair.com.
