balance.py File Reference

Balancing Ball Main File. More...

Variables
	balance.pinB6 = pyb.Pin.cpu.B6
	balance.pinB7 = pyb.Pin.cpu.B7
	balance.e1 = e(pinB6, pinB7, 4)
	balance.pinC6 = pyb.Pin.cpu.C6
	balance.pinC7 = pyb.Pin.cpu.C7
	balance.e2 = e(pinC6, pinC7, 8)
	balance.pinA15 = pyb.Pin.cpu.A15
	balance.pinB2 = pyb.Pin.board.PB2
	balance.pinB4 = pyb.Pin.cpu.B4
int	balance.ch1 = 1
	balance.pinB5 = pyb.Pin.cpu.B5
int	balance.ch2 = 2
bool	balance.motor1 = True
	balance.pinB0 = pyb.Pin.cpu.B0
int	balance.ch3 = 3
	balance.pinB1 = pyb.Pin.cpu.B1
int	balance.ch4 = 4
bool	balance.motor2 = False
int	balance.tim = 3
	balance.m1 = m(motor1, pinA15, pinB2, pinB4, ch1, pinB5, ch2, tim)
	balance.m2 = m(motor2, pinA15, pinB2, pinB0, ch3, pinB1, ch4, tim)
	balance.xp = Pin.cpu.A0
	balance.xm = Pin.cpu.A6
	balance.yp = Pin.cpu.A7
	balance.ym = Pin.cpu.A1
float	balance.w = 0.1
float	balance.l = 0.176
float	balance.xc = l/2
float	balance.yc = w/2
	balance.ts = t(xp, xm, yp, ym, w, l, xc, yc)
int	balance.K1 = -100
int	balance.K2 = -50
int	balance.K3 = -500
int	balance.K4 = -20
int	balance.x_0 = 0
int	balance.y_0 = 0
int	balance.V_DC = 12
float	balance.R = 2.21
float	balance.K_T = 13.8
int	balance.duty_conv = 100*R/(V_DC*K_T)
	balance.start_time = utime.ticks_ms()
	balance.inpt = input('Manually level the platform. Press "0" when platform is ready: ')
	balance.val = int(inpt)
	balance.theta_y_0 = e1.set_position(0)
	balance.theta_x_0 = e2.set_position(0)
	balance.curr_time = utime.ticks_ms()
	balance.delta_t = utime.ticks_diff(curr_time, start_time)
	balance.P = ts.coord()
int	balance.theta_y_1 = 2*3.14*e1.get_position()/4000
tuple	balance.thetadot_y = (theta_y_1 - theta_y_0)/ delta_t
	balance.x_1 = P[0]
tuple	balance.xdot = (x_1 - x_0)/delta_t
int	balance.T_x = -K1*xdot - K2*thetadot_y - K3*x_1 - K4*theta_y_1
	balance.Duty_x = int(-1*duty_conv*T_x)
int	balance.theta_x_1 = 2*3.14*e2.get_position()/4000
tuple	balance.thetadot_x = (theta_x_1 - theta_x_0)/ delta_t
	balance.y_1 = P[1]
tuple	balance.ydot = (y_1 - y_0)/delta_t
int	balance.T_y = -K1*ydot - K2*thetadot_x - K3*y_1 - K4*theta_x_1
	balance.Duty_y = int(duty_conv*T_y)

Detailed Description

Balancing Ball Main File.

This code is Kyle's attempt at balancing the ball. It involves manually zeroing the platform then inputting 0 to begin the balancing process. There is a failsafe where the motors will disable when there is no input to the touchscreen, so the platform balancing will start once the ball is placed onto the platform.

This code requires the encoder, motor, and touchscreen drivers made previously for successsful operation, as they provide inputs (ball position data from the touchscreen and the theta data from the encoders) to our control system. The output of the control system is torque supplied to the motor shafts (T_x and T_y) which are converted to motor duty cycle values using a constant gain conversion derived from the motor data sheet. The result is two motor objects that each control an axis of tilt for the platform which react to the location of the ball.

Author

Kyle Chuang

Enoch Nicholson

Date

March 15, 2021