AVR Freaks

            req_angle=45;	
	    velocity_x=cos(req_angle*val);  velocity_y=sin(req_angle*val);
		
		velocity_1 = - velocity_x*(sin(theta*val))           +    velocity_y*(cos(theta*val)) + radius*omega;
	        velocity_2 = - velocity_x*(sin((theta + 120)*val))   +    velocity_y*(cos((theta + 120)*val)) + radius*omega;
		velocity_3 = - velocity_x*(sin((theta + 240)*val))   +    velocity_y*(cos((theta + 240)*val)) + radius*omega;

These are my equations for the three wheels of the omni robot. Required angle signifies the angle in which we move with respect to the x axis. Theta stores the orientation of the bot using an imu, which is zero on the x axis. They are correct.

I dont know what do I do with the term omega and on what should I apply my PID correction.

Here is a rough and general code Ive written for PID which ofcourse doesnt run at the moment.

int pid()
{	
        //kp, ki, kd store some constant values	
	int error = target_position - current_position;
	

	int integral = integral + error;
	int derivative = error - last_error;
	int pwm= (kp * error) + (ki*integral) + (kd*derivative);


	if(pwm>255)
		pwm=255;
	if(pwm<-255)
		pwm=-255;

	if(pwm>0)
		direction=clockwise;
	if(pwm<0)
		direction=anticlockwwise;
	else
 		brake;

	int last_error = error;
	
}