Arduino for Motorised Wheelchair

Hii  bobbyppaul

here are answers of your questions...

1. How effectively can we use Arduino for Motorised Wheelchair ?

Ans: Arduino can easily control 4 DC Motors (I dont think Wheel Chair need more than 4 motors) using PWM very efficiently.. It also have Enough ADC input to connect Joy Stick(Simplest way to control wheel chair)

2. I heard from someone that Arduino is not reliable and it will burn off easily is it true ?

Ans: Not true at all... Arduino is just programmable small computer... Due to human error by means of wrong wiring / Wrong code can burn other hardware (i.e. motor driver) and wrong power supply or applying more than specified voltage (i.e. 5V for Arduino) to input pin of Arduino can damage arduino.. but this is true for all microcontroller in the world..

3. Can anyone help me developing a circuit which is reliable and consistent ?

Ans: Surely community members here(including me ) always happy to help you.. Also As you are faculty (me too ), I think your institute/university definitely have Electronics/Electrical department, so you can get get help from students or faculty of these department who frequently using arduino.

4: I did some experimentation with Arduino and Relays we had jerks in wheelchair as it was just helping to switch on and off and Relay was burning off frequently.

Ans: As relay directly run motor with max torque, jerks are obvious, to solve it you need to use PWM with motor driver to get throttle (speed here) of motor, have a look at answer of next question for more clarity.

5: I am trying to use motor Driver L293D to control the motors.

Ans: L293d will not work as it can be used up to 1 or 1.5 Amp current maximum per channel... Your specification needs lot more current (normally working 10-15 Amps and stall current of motor will be more than 20amps) So I suggest use H-bridge using IRF540 and IRF9540 MOSFETs which can easily handle 25 Amps, Its very low cost solution and using PWM channel arduino u can control speed of motor too.. (not just on-off which is case of relay)

6: Can I use 'map' function to link Joystick input and motor output. Is it the best way to do it ? Or is their any other alternatives.

Ans: yes its a best way to do, as joy stick output dynamic range is 0-1023 but PWM for motor output dynamic is 0-255, map function will serve mapping of this ranges to get max throughput on motor. There are other alternatives also to get user input but I dont think your use case needs it to be explore..

Hope this helps...

Ravi

I have a doubt. My motor is only 3Amps and the suggested method is for 10-15 Amps. Could you please clarify.

Two Motion tech 24 Volt, 320 Watts, 3 Amps DC motors..

1. If your motors are rated by current 3Amp than Watt will be 24x3=72Watts

2. If your motors are rated by Power 320Watts than Max Current will be 320/24 = 13.33 amp

So there is some confusion with rating you have mentioned... But good thing for you is in any case 1 or 2 IRF540+IRF9540 H-Bridge will work as in both case current is too below mosfet ratings 25Amp...

Load(motor in your case) will draw current based on its winding resistance and supplied voltage... while driver current rating is maximum current up to which driver can drive the load..

All in All... Its good to drive 3Amp motor with 15Amp driver (motor will draw only 3amps).. but if you drive 15Amp motor with 3Amp driver than driver get overloaded and get fried up with smoke around

Thank you very much for the guidance....

Thank you very much ...

Is there any ready made driver which I can buy and go ahead with my work....or do I have to make it.....

Episode 48: See Ben Heck's Motorized Wheelchair Episode  is perfect for your requirement as beacon_dave mentioned...

In the same video Mosfet based H bridge is also mentioned that you can use...

Thank you very much Mr Ravi

Thank you very much Mr Ravi