import numpy as np import math import time class PIDController: def __init__(self, estimator): self.t = time.time() self.estimator = estimator self.controlling = False self.P_angle = 0.4 # PID parameters determined by Ziegler-Nichols. measured K_crit = 1.4, T_crit = 1.5 self.I_angle = 0.35 self.D_angle = 0.1 self.P_pos = 0.50 self.I_pos = 0.3 self.D_pos = 0.1 self.mode = None def move_to_pos(self, target_pos, robot, near_target_counter=5): near_target = 0 while near_target < near_target_counter: while not self.estimator.event_queue.empty(): event = self.estimator.event_queue.get() print("event: ", event) if event[0] == 'click': pass elif event[0] == 'key': key = event[1] if key == 84: # arrow up self.controlling = True self.t = time.time() elif key == 82: # arrow down self.controlling = False robot.send_cmd() elif key == 48: # 0 target_pos = np.array([0.0, 0.0, 0.0]) elif key == 43: # + self.control_scaling += 0.1 self.control_scaling = min(self.control_scaling, 1.0) print("control scaling = ", self.control_scaling) elif key == 45: # - self.control_scaling -= 0.1 self.control_scaling = max(self.control_scaling, 0.1) print("control scaling = ", self.control_scaling) elif key == 113: print("quit!") self.controlling = False robot.send_cmd() return elif key == 27: # escape print("quit!") self.controlling = False robot.send_cmd() return x_pred = self.get_measurement(robot.id) if x_pred is not None: error_pos = np.linalg.norm(x_pred[0:2] - target_pos[0:2]) angles_unwrapped = np.unwrap([x_pred[2], target_pos[2]]) # unwrap angle to avoid jump in data error_ang = np.abs(angles_unwrapped[0] - angles_unwrapped[1]) # print("error pos = ", error_pos) # print("error_pos = {}, error_ang = {}".format(error_pos, error_ang)) # if error_pos > 0.075 or error_ang > 0.35: if error_pos > 0.05 or error_ang > 0.1: # solve mpc open loop problem res = self.ols.solve(x_pred, target_pos) # us1 = res[0] # us2 = res[1] us1 = res[0] * self.control_scaling us2 = res[1] * self.control_scaling # print("u = {}", (us1, us2)) # print("---------------- mpc solution took {} seconds".format(tmpc_end - tmpc_start)) dt_mpc = time.time() - self.t if dt_mpc < self.dt: # wait until next control can be applied # print("sleeping for {} seconds...".format(self.dt - dt_mpc)) time.sleep(self.dt - dt_mpc) else: us1 = [0] * self.mstep us2 = [0] * self.mstep near_target += 1 # send controls to the robot for i in range(0, self.mstep): # option to use multistep mpc if len(range) > 1 u1 = us1[i] u2 = us2[i] robot.send_cmd(u1, u2) if i < self.mstep: time.sleep(self.dt) self.t = time.time() # save time the most recent control was applied else: print("robot not detected yet!") def interactive_control(self, robots): controlled_robot_number = 0 robot = robots[controlled_robot_number] ts = [] angles = [] target_pos = np.array([0.0, 0.0, 0.0]) e_angle_old = 0.0 e_pos_old = 0.0 i = 0.0 i_angle = 0.0 i_pos = 0.0 t0 = time.time() running = True while running: # handle events from opencv window while not self.estimator.event_queue.empty(): event = self.estimator.event_queue.get() print("event: ", event) if event[0] == 'click': target_pos = event[1] i_angle = 0 i_pos = 0 e_pos_old = 0 e_angle_old = 0 self.mode = 'combined' elif event[0] == 'key': key = event[1] if key == 32: # arrow up self.controlling = not self.controlling if not self.controlling: print("disable control") robot.send_cmd() # stop robot self.mode = None # reset control mode else: print("enable control") i = 0 self.t = time.time() elif key == 48: # 0 target_pos = np.array([0.0, 0.0, 0.0]) # TODO: use center of board for target pos elif key == 97: # a self.mode = 'angle' e_angle_old = 0 i = 0 self.t = time.time() elif key == 99: # c self.mode = 'combined' e_angle_old = 0 e_pos_old = 0 i_angle = 0 i_pos = 0 self.t = time.time() elif key == 112: # p self.mode = 'position' e_pos_old = 0 i = 0 self.t = time.time() elif key == 43: # + self.P_pos += 0.1 print("P = ", self.P_angle) elif key == 45: # - self.P_pos -= 0.1 print("P = ", self.P_angle) elif key == 9: # TAB # switch controlled robot robot.send_cmd() # stop current robot controlled_robot_number = (controlled_robot_number + 1) % len(robots) robot = robots[controlled_robot_number] print(f"controlled robot: {robot.id}") elif key == 113 or key == 27: # q or ESCAPE print("quit!") self.controlling = False robot.send_cmd() return if self.controlling: # measure state x_pred = self.get_measurement(robot.id) dt = self.t - time.time() #print(f"x_pred = {x_pred}\ntarget = {target_pos}\nerror = {np.linalg.norm(target_pos - x_pred)}\n") if self.mode == 'angle': # compute angle such that robot faces to target point target_angle = target_pos[2] ts.append(time.time() - t0) angles.append(x_pred[2]) angles_unwrapped = np.unwrap([x_pred[2], target_angle]) # unwrap angle to avoid jump in data e_angle = angles_unwrapped[0] - angles_unwrapped[1] # angle difference p = self.P_angle * e_angle # i += self.I * dt * e # right Riemann sum i += self.I_angle * dt * (e_angle + e_angle_old)/2.0 # trapezoidal rule d = self.D_angle * (e_angle - e_angle_old)/dt u1 = p - i - d u2 = - u1 e_angle_old = e_angle elif self.mode == 'combined': # compute angle such that robot faces to target point v = target_pos[0:2] - x_pred[0:2] target_angle = math.atan2(v[1], v[0]) angles_unwrapped = np.unwrap([x_pred[2], target_angle]) # unwrap angle to avoid jump in data e_angle = angles_unwrapped[0] - angles_unwrapped[1] # angle difference e_pos = np.linalg.norm(v) if e_pos < 0.05: self.mode = 'angle' e_angle_old = 0 e_pos_old = 0 i_angle = 0 i_pos = 0 u1 = 0 u2 = 0 else: forward = abs(e_angle) < np.pi/2.0 if not forward: if e_angle > np.pi/2.0: e_angle -= np.pi else: e_angle += np.pi p_angle = self.P_angle * e_angle i_angle += self.I_angle * dt * (e_angle + e_angle_old) / 2.0 # trapezoidal rule d_angle = self.D_angle * (e_angle - e_angle_old) / dt p_pos = self.P_pos * e_pos i_pos += self.I_pos * dt * (e_pos + e_pos_old) / 2.0 # trapezoidal rule d_pos = self.D_pos * (e_pos - e_pos_old) / dt if forward: print("forward") u1 = p_angle + p_pos - i_angle - i_pos - d_angle - d_pos u2 = - p_angle + p_pos + i_angle - i_pos + d_angle - d_pos else: print("backward") u1 = p_angle - p_pos - i_angle + i_pos - d_angle + d_pos u2 = - p_angle - p_pos + i_angle + i_pos + d_angle + d_pos e_pos_old = e_pos e_angle_old = e_angle else: u1 = 0.0 u2 = 0.0 #print(f"u = ({u1}, {u2})") robot.send_cmd(u1, u2) self.t = time.time() # save time when the most recent control was applied time.sleep(0.1) def get_measurement(self, robot_id): return self.estimator.get_robot_state_estimate(robot_id)