#!/usr/bin/env python # -*- coding: utf-8 -*- """Center of mass manipulability tracking Track the velocity manipulability ellipsoid of the center of mass of a particular robot while keeping its balance. See Also: - `com_manipulability_tracking.py`: in this example, the base is fixed. - `com_dynamic_manipulability_tracking_with_balance.py`: in this example, the dynamic manipulability ellipsoid is tracked instead of the velocity one. References: [1] "Robotics: Modelling, Planning and Control" (section 3.9), Siciliano et al., 2010 [2] "Geometry-aware Tracking of Manipulability Ellipsoids", Jaquier et al., R:SS, 2018 """ import time # from itertools import count import numpy as np from scipy.linalg import block_diag import matplotlib.pyplot as plt import argparse from pyrobolearn.simulators import Bullet from pyrobolearn.worlds import BasicWorld from pyrobolearn.robots import Nao, Centauro # create parser parser = argparse.ArgumentParser() parser.add_argument('-r', '--robot', help='the robot to track the velocity manipulability ellipsoid', type=str, choices=['nao', 'centauro'], default='nao') parser.add_argument('-n', '--init_manipulability', help='which desired velocity manipulability we want to track', type=int, default=4) parser.add_argument('-i', '--init_config', help='the initial configuration for the robot', type=int, choices=range(1, 5), default=1) args = parser.parse_args() # program variable robot_name = args.robot dt = 0.01 # Sampling time num_des_manip = args.init_manipulability # Number of desired manipulability (Useful for tests) init_qs = args.init_config # Number of initial configuration for the robots (Useful for tests) # Create simulator and world sim = Bullet() world = BasicWorld(sim) # load robot if robot_name == 'nao': robot = Nao(sim, fixed_base=False) elif robot_name == 'centauro': robot = Centauro(sim, fixed_base=False) else: raise NotImplementedError("The given robot has not been implemented") # Loop for setting stable initial conditions for i in range(50): world.step(sleep_dt=0.1) # Define velocity manipulability for CoM, proportional gain, and initial configurations if robot.name == 'nao': Km = 100 * np.eye(6) # Proportional gain for Nao for manip. tracking # desired Velocity Manipulability for CoM (Nao) des_manips = np.array([[[1.539e-03, 6.653e-04, 0.833e-04], [6.653e-04, 2.080e-03, -5.843e-05], [0.833e-04, -5.843e-05, 8.601e-04]], [[2.580e-03, 1.653e-03, 4.833e-04], [1.653e-03, 1.539e-03, -5.843e-05], [4.833e-04, -5.843e-05, 9.601e-04]], [[1.580e-03, .653e-03, 4.833e-04], [.653e-03, 1.539e-03, -5.843e-05], [4.833e-04, -5.843e-05, 9.601e-04]], [[1e-04, 0.0, 0.0], [0.0, 5e-04, 0.0], [0.0, 0.0, 1e-04]]]) des_vel_manip = des_manips[num_des_manip - 1, :, :] # Get ids for feet (used for kinematics function) left_foot_id = robot.get_link_ids('l_ankle') right_foot_id = robot.get_link_ids('r_ankle') # Gain matrices Kcom = np.diag((50, 40, 0)) # Proportional gain for CoM position control Klf = np.diag((20, 20, 20)) # Proportional gain for foot position control Krf = np.diag((20, 20, 20)) # Proportional gain for foot position control # Setting initial configuration of the robot if init_qs == 1: q0 = [1.55, 0.135, -1.05, -0.36, 1.55, -0.135, 1.05, 0.36] q0id = ['LShoulderPitch', 'LShoulderRoll', 'LElbowYaw', 'LElbowRoll', 'RShoulderPitch', 'RShoulderRoll', 'RElbowYaw', 'RElbowRoll'] elif init_qs == 2: q0 = [1.55, 0.135, -1.05, -0.36, 1.55, -0.135, 1.05, 0.36, 0.1, -0.1, 0.12, 0.12, -0.12, -0.12] q0id = ['LShoulderPitch', 'LShoulderRoll', 'LElbowYaw', 'LElbowRoll', 'RShoulderPitch', 'RShoulderRoll', 'RElbowYaw', 'RElbowRoll', 'LHipRoll', 'RHipRoll', 'LKneePitch', 'RKneePitch', 'LAnklePitch', 'RAnklePitch'] elif init_qs == 3: q0 = [2.0, 0.4, -1.3, -1.2, 2.0, -0.4, 1.3, 1.2, 0.05, -0.05, 0.2, 0.2, -0.2, -0.2] q0id = ['LShoulderPitch', 'LShoulderRoll', 'LElbowYaw', 'LElbowRoll', 'RShoulderPitch', 'RShoulderRoll', 'RElbowYaw', 'RElbowRoll', 'LHipRoll', 'RHipRoll', 'LKneePitch', 'RKneePitch', 'LAnklePitch', 'RAnklePitch'] else: q0 = 0 q0id = 0 elif robot.name == 'centauro': Km = 50 * np.eye(6) # Proportional gain for Centauro # desired Velocity Manipulability for CoM (Centauro) des_manips = np.array([[[0.0207, 0.008, 0.0], [0.008, 0.01, -0.005], [0.0, -0.005, 0.006]], [[5.173e-03, -2.733e-03, 1.920e-03], [-2.733e-03, 2.038e-02, 7.185e-04], [1.920e-03, 7.185e-04, 2.107e-03]], [[2.2e-02, 0.0, -0.01], [0.0, 2.1e-02, 0.0], [-0.01, 0.0, 5.e-03]], [[5e-04, 0.0, 0.0], [0.0, .1, 0.0], [0.0, 0.0, 5e-04]]]) des_vel_manip = des_manips[num_des_manip - 1, :, :] print("desired velocity manipulability: {}".format(des_vel_manip)) # Get ids for "feet" (used for kinematics function) left_foot1_id = robot.get_link_ids('wheel_1') right_foot1_id = robot.get_link_ids('wheel_2') left_foot2_id = robot.get_link_ids('wheel_3') right_foot2_id = robot.get_link_ids('wheel_4') # Gain matrices Kcom = np.diag((250.0, 250.0, 0.0)) # Proportional gain for CoM position control Kl1f = np.diag((180, 180, 180)) # Proportional gain for foot position control Kr1f = np.diag((180, 180, 180)) # Proportional gain for foot position control Kl2f = np.diag((180, 180, 180)) # Proportional gain for foot position control Kr2f = np.diag((180, 180, 180)) # Proportional gain for foot position control # Setting initial configuration of the robot if init_qs == 1: q0 = [-.7, -.65, .61, -.5, .71, .64, -.68, .7] q0id = ['j_arm1_1', 'j_arm1_2', 'j_arm1_3', 'j_arm1_4', 'j_arm2_1', 'j_arm2_2', 'j_arm2_3', 'j_arm2_4'] elif init_qs == 2: q0 = [-.7, -.65, .61, -.5, .71, .64, -.68, .7, -0.42, -0.96, -0.59, 0.42, 0.96, 0.59, 0.42, 0.96, 0.59, -0.42, -0.96, -0.59] q0id = ['j_arm1_1', 'j_arm1_2', 'j_arm1_3', 'j_arm1_4', 'j_arm2_1', 'j_arm2_2', 'j_arm2_3', 'j_arm2_4', 'hip_pitch_1', 'knee_pitch_1', 'ankle_pitch_1', 'hip_pitch_2', 'knee_pitch_2', 'ankle_pitch_2', 'hip_pitch_3', 'knee_pitch_3', 'ankle_pitch_3', 'hip_pitch_4', 'knee_pitch_4', 'ankle_pitch_4'] elif init_qs == 3: q0 = [-.3, -1.3, .61, -.5, .3, 1.3, -.68, .7, -0.42, -0.96, -0.59, 0.42, 0.96, 0.59, 0.42, 0.96, 0.59, -0.42, -0.96, -0.59] q0id = ['j_arm1_1', 'j_arm1_2', 'j_arm1_3', 'j_arm1_4', 'j_arm2_1', 'j_arm2_2', 'j_arm2_3', 'j_arm2_4', 'hip_pitch_1', 'knee_pitch_1', 'ankle_pitch_1', 'hip_pitch_2', 'knee_pitch_2', 'ankle_pitch_2', 'hip_pitch_3', 'knee_pitch_3', 'ankle_pitch_3', 'hip_pitch_4', 'knee_pitch_4', 'ankle_pitch_4'] else: q0 = 0 q0id = 0 else: left_foot_id, right_foot_id = 0, 0 # Loop need to set the robot initial posture if not (isinstance(q0, int) and q0 == 0 and isinstance(q0id, int) and q0id == 0): for n in range(15): robot.set_joint_positions(np.asarray(q0), robot.get_joint_ids(np.asarray(q0id))) world.step() # Augmented gain matrix for balancing controller if robot.name == 'centauro': Kbal = block_diag(Kl1f, Kr1f, Kl2f, Kr2f, Kcom) else: Kbal = block_diag(Klf, Krf, Kcom) print("Kbal: {}".format(Kbal)) # Initial conditions time.sleep(2.0) num_dofs = robot.num_dofs - 6 CoMr = robot.get_center_of_mass_position() # Desired CoM print("CoMr: {}".format(CoMr)) if robot.name == 'centauro': xref_l1f = robot.get_link_world_frame_positions(left_foot1_id) # Desired position for left foot xref_r1f = robot.get_link_world_frame_positions(right_foot1_id) # Desired position for right foot xref_l2f = robot.get_link_world_frame_positions(left_foot2_id) # Desired position for left foot xref_r2f = robot.get_link_world_frame_positions(right_foot2_id) # Desired position for right foot else: xref_lf = robot.get_link_world_frame_positions(left_foot_id) # Desired position for left foot # Qref_lf = robot.get_link_world_frame_orientations(leftFootId) xref_rf = robot.get_link_world_frame_positions(right_foot_id) # Desired position for right foot # Qref_rf = robot.get_link_world_frame_orientations(rightFootId) # Display initial and desired manipulability ellipsoid robot = world.load_robot(robot) world.step() q0 = robot.get_joint_positions() print("q0: {}".format(q0)) Jcom0 = robot.get_center_of_mass_jacobian(q0) if not robot.has_fixed_base(): vel_manip = robot.compute_velocity_manipulability_ellipsoid(Jcom0[:, 6:]) else: vel_manip = robot.compute_velocity_manipulability_ellipsoid(Jcom0) print("Mv0: {}".format(vel_manip[0:3, 0:3])) base_pos = robot.get_base_position() robot.draw_velocity_manipulability_ellipsoid(link_id=-1, JJT=10 * des_vel_manip, color=(0.1, 0.75, 0.1, 0.6)) ellipsoid_id = robot.draw_velocity_manipulability_ellipsoid(link_id=-1, JJT=10 * vel_manip[0:3, 0:3], color=(0.75, 0.1, 0.1, 0.6)) # Logging variables # Format: [q minEigvalue(Jbal) minEigvalue(Jman) balanceError CurrentManip(1x9) SPDdistance] log_array = np.zeros((400, num_dofs + 2 + Kbal.shape[0] + vel_manip[0:3, 0:3].size + 1)) # Run simulator # for i in count(): for i in range(400): # Update current robot state qt = robot.get_joint_positions() CoMt = robot.get_center_of_mass_position() # Current CoM robot.draw_com_position(0.03) if robot.name == 'centauro': xt_l1f = robot.get_link_world_frame_positions(left_foot1_id) # Current position for left foot xt_r1f = robot.get_link_world_frame_positions(right_foot1_id) # Current position for right foot xt_l2f = robot.get_link_world_frame_positions(left_foot2_id) # Current position for left foot xt_r2f = robot.get_link_world_frame_positions(right_foot2_id) # Current position for right foot else: xt_lf = robot.get_link_world_frame_positions(left_foot_id) # Current left foot pos # Qt_lf = robot.get_link_world_frame_orientations(leftFootId) xt_rf = robot.get_link_world_frame_positions(right_foot_id) # Current right foot pos # Simple balance control with IK kinematics for CoM and feet # Get Jacobians: Jcom, Jlf, and Jrf Jcom = robot.get_center_of_mass_jacobian(qt) if robot.name == 'centauro': Jl1f = robot.get_jacobian(left_foot1_id, qt) Jr1f = robot.get_jacobian(right_foot1_id, qt) Jl2f = robot.get_jacobian(left_foot2_id, qt) Jr2f = robot.get_jacobian(right_foot2_id, qt) else: Jlf = robot.get_jacobian(left_foot_id, qt) Jrf = robot.get_jacobian(right_foot_id, qt) # Compose Jacobian and nullspace for balancing task if robot.name == 'centauro': Jbal = np.vstack((Jl1f[0:3, ], Jr1f[0:3, ], Jl2f[0:3, ], Jr2f[0:3, ], Jcom[0:3, ])) else: Jbal = np.vstack((Jlf[0:3, ], Jrf[0:3, ], Jcom[0:3, ])) Ubal, Sbal, VhBal = np.linalg.svd(Jbal) if np.min(Sbal) < 4.5E-2: pJbal = robot.get_damped_least_squares_inverse(Jbal, 4.5E-2) else: pJbal = robot.get_damped_least_squares_inverse(Jbal, 1E-8) Nbal = np.eye(Jbal.shape[1]) - np.dot(pJbal, Jbal) # Compute balancing task errors dx_com = CoMr - CoMt # CoM error if robot.name == 'centauro': dx_l1f = xref_l1f - xt_l1f # Left foot position error dx_r1f = xref_r1f - xt_r1f # Right foot position error dx_l2f = xref_l2f - xt_l2f # Left foot position error dx_r2f = xref_r2f - xt_r2f # Right foot position error dx_bal = np.vstack((dx_l1f.reshape(3, 1), dx_r1f.reshape(3, 1), dx_l2f.reshape(3, 1), dx_r2f.reshape(3, 1), dx_com.reshape(3, 1))) # Augmented error vector else: dx_lf = xref_lf - xt_lf # Left foot position error dx_rf = xref_rf - xt_rf # Right foot position error dx_bal = np.vstack((dx_lf.reshape(3, 1), dx_rf.reshape(3, 1), dx_com.reshape(3, 1))) # Augmented error vector # dx_bal = np.vstack((np.zeros((6, 1)), dx_com.reshape(3, 1))) # Augmented error vector # Proportional controller for position dxref_bal = np.dot(Kbal, dx_bal) # Compute desired joint velocities for balancing dq_bal = np.dot(pJbal, dxref_bal) dq_bal = dq_bal.reshape((Jbal.shape[1],)) # Tracking of CoM velocity manipulability in nullspace if not robot.has_fixed_base(): vel_manip = robot.compute_velocity_manipulability_ellipsoid(Jcom[:, 6:]) else: vel_manip = robot.compute_velocity_manipulability_ellipsoid(Jcom) # Plot current manipulability ellipsoid if i % 40 == 0: ellipsoid_id = robot.update_manipulability_ellipsoid(link_id=-1, ellipsoid_id=ellipsoid_id, ellipsoid=10 * vel_manip[:3, :3], color=(0.75, 0.1, 0.1, 0.6)) # Obtaining joint velocity command if not robot.has_fixed_base(): dq_man, minSman, SPDdist = robot.calculate_inverse_differential_kinematics_velocity_manipulability(Jcom[:, 6:], des_vel_manip, Km) # dq_man = np.vstack((np.zeros((6, 1)), dq_man.reshape(num_dofs, 1))) else: dq_man, minSman, SPDdist = robot.calculate_inverse_differential_kinematics_velocity_manipulability(Jcom, des_vel_manip, Km) # Logging # Format: [q minEigvalue(Jbal) minEigvalue(Jman) balanceError CurrentManip(1x9) SPDdistance] log_array[i,] = np.hstack((qt.reshape(1, num_dofs), np.min(Sbal).reshape(1, 1), minSman.reshape(1, 1), dx_bal.T, vel_manip[0:3, 0:3].reshape(1, vel_manip[0:3, 0:3].size), SPDdist.reshape(1, 1))) # Set joint position if not robot.has_fixed_base(): dq_man = np.concatenate((np.zeros((6,)), dq_man)) dq = dq_bal + np.dot(Nbal, dq_man) dq = dq[6:, ] else: dq = dq_bal + np.dot(Nbal, dq_man) q = qt + (dq * dt) robot.set_joint_positions(q) world.step(sleep_dt=dt) # Saving log data # np.savetxt(robot.name + 'log_Man' + str(num_des_manip) + 'Pos' + str(init_qs) + '.csv', log_array, delimiter=',') # Plotting logged data fig1 = plt.figure(1, figsize=(14, 10)) # wspace: width reserved for blank space between subplots, hspace: height reserved for white space between subplots fig1.subplots_adjust(left=0.09, bottom=0.05, right=0.99, wspace=0.2) plt.suptitle('Robot joints') plt.rcParams.update({'font.size': 8}) for i in range(num_dofs): if robot.name == 'nao': plt.subplot(6, 7, i+1) # NAO elif robot.name == 'centauro': plt.subplot(7, 7, i + 1) # Centauro plt.ylabel(robot.get_joint_names(robot.get_joint_ids(i))) plt.plot(log_array[:, i]) plt.ylim((-1.5, 1.5)) # fig1.savefig(robot.name + '_joints_Man' + str(num_des_manip) + 'Pos' + str(init_qs) + '.png', # bbox_inches='tight', dpi=200) fig2 = plt.figure(2, figsize=(14, 10)) fig2.subplots_adjust(left=0.09, bottom=0.05, right=0.99, wspace=0.2) plt.rcParams.update({'font.size': 12}) plt.suptitle('MinEigenvalues, balance and manipulatility errors.') plt.rcParams.update({'font.size': 8}) if robot.name == 'nao': plt.subplot(4, 3, 1) # NAO plt.ylim((0, 0.05)) # NAO elif robot.name == 'centauro': plt.subplot(6, 3, 1) # Centauro plt.ylim((0, 0.02)) # Centauro plt.ylabel('minEigvalue(Jbal)') plt.plot(log_array[:, num_dofs]) if robot.name == 'nao': plt.subplot(4, 3, 2) # NAO plt.ylim((0., 0.0001)) # NAO elif robot.name == 'centauro': plt.subplot(6, 3, 2) # Centauro plt.ylim((0., 0.001)) # Centauro plt.ylabel('minEigvalue(Jman)') plt.plot(log_array[:, num_dofs + 1]) if robot.name == 'nao': plt.subplot(4, 3, 3) # NAO plt.ylim((0., 4.0)) # NAO elif robot.name == 'centauro': plt.subplot(6, 3, 3) # Centauro plt.ylim((0., 5.0)) # Centauro plt.ylabel('SPDdist') plt.plot(log_array[:, -1]) for i in range(dx_bal.shape[0]): if robot.name == 'nao': plt.subplot(4, 3, i+4) # NAO elif robot.name == 'centauro': plt.subplot(6, 3, i + 4) # Centauro plt.ylabel('dx_bal'+str(i+1)) plt.plot(log_array[:, num_dofs + 2 + i]) plt.ylim((-.05, .05)) # fig2.savefig(robot.name + '_eigValsAndErrors_Man' + str(num_des_manip) + 'Pos' + str(init_qs) + '.png', # bbox_inches='tight') # plt.tight_layout() plt.show()