File size: 5,656 Bytes
aad4e51 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 | """Draw the geometry, contact-to-point calculation and recorded loading sequence."""
from pathlib import Path
import json
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
from matplotlib.patches import FancyBboxPatch
import numpy as np
ROOT = Path(__file__).resolve().parents[1]
OUTPUT = ROOT / 'renders/tactile'
plt.rcParams.update({'font.size': 11, 'axes.spines.top': False, 'axes.spines.right': False})
config = json.loads((ROOT / 'sensors/paxini_m3025/config/m3025.json').read_text(encoding='utf-8'))
points = np.asarray(config['positions_m']) * 1000
normals = np.asarray(config['outward_normals_sensor'])
data = np.load(ROOT / 'validation/tactile/gripper_newton.npz')
time = data['time_s']
index = int(np.argmin(abs(time - 1.95)))
force = data['forces_sensor_n'][index, 0]
compression = data['normal_compression_n'][index, 0]
fig = plt.figure(figsize=(14, 8.5), dpi=160, facecolor='#f4f7fb')
grid = fig.add_gridspec(2, 3, left=.055, right=.955, top=.82, bottom=.12, wspace=.36, hspace=.56)
ax = fig.add_subplot(grid[0, 0], projection='3d')
ax.scatter(*points.T, c=normals[:, 2], cmap='Blues', s=26, vmin=-.2, vmax=1)
ax.quiver(*points[::5].T, *normals[::5].T, length=3, color='#2476a7', linewidth=.6)
ax.set(xlabel='x (mm)', ylabel='y (mm)', zlabel='z (mm)', title='Vendor geometry and 77 sensing positions')
ax.view_init(elev=27, azim=-66)
ax.set_box_aspect([25, 31, 10])
ax = fig.add_subplot(grid[0, 1])
ax.axis('off')
ax.text(0, .92, 'Rigid-body contact solver', fontsize=15, weight='bold')
ax.text(0, .72, 'MuJoCo / Isaac PhysX / Isaac Newton', fontsize=11)
ax.text(0, .58, 'Per contact:\nposition + outward normal\nnormal force + friction force', fontsize=12, linespacing=1.6, va='top')
ax.text(0, .04, 'Newton uses actual MuJoCo Warp\ncontact forces on the CUDA device.', fontsize=11, color='#496278')
ax = fig.add_subplot(grid[0, 2])
scatter = ax.scatter(points[:, 0], points[:, 1], c=compression, s=85, cmap='viridis', edgecolors='#556677', lw=.4)
ax.quiver(points[:, 0], points[:, 1], force[:, 0], force[:, 1], color='#d45d34',
angles='xy', scale_units='xy', scale=.02, width=.008)
ax.set(xlabel='Sensor x (mm)', ylabel='Sensor y (mm)', title='Left array: recorded Newton contact', aspect='equal')
fig.colorbar(scatter, ax=ax, label='Local compression (N)', fraction=.05, pad=.04)
ax = fig.add_subplot(grid[1, :2])
ax.axis('off')
ax.text(0, 1, 'Contact-to-point observation model', fontsize=15, weight='bold')
ax.text(0, .71, r'$w_i = \frac{\exp[-\|\mathbf{p}_i-\mathbf{p}_c\|^2/(2\sigma^2)]\,a_i^2}'
r'{\sum_j \exp[-\|\mathbf{p}_j-\mathbf{p}_c\|^2/(2\sigma^2)]\,a_j^2}$', fontsize=19)
ax.text(0, .43, r'$a_i=\max(\mathbf{n}_i\cdot\mathbf{n}_c,0),\qquad\mathbf{f}_i=\sum_c w_{ic}\mathbf{f}_c$', fontsize=17)
ax.text(0, .14, 'Spatial width = 2.5 mm; acceptance distance = 4 mm. Both are uncalibrated.\n'
'Only aligned points within four spatial widths receive force.\n'
'Accepted total force is conserved; distributed point moments are not conserved.', fontsize=10, linespacing=1.5)
ax = fig.add_subplot(grid[1, 2])
for side, color in enumerate(['#1676b9', '#dd682b']):
ax.plot(time, -data['contact_wrench_sensor'][:, side, 2], color=color, label=['Left', 'Right'][side], lw=1.2)
ax.axvspan(2.1, 2.7, color='#e0e7ee', label='Block translation')
ax.set(xlabel='Time (s)', ylabel='Compression -Fz (N)', title='Close, hold, translate and release')
ax.grid(alpha=.2)
ax.legend(fontsize=9, loc='upper right')
fig.suptitle('M3025 contact observation for the complete custom gripper', x=.055, ha='left', y=.96,
fontsize=22, weight='bold', color='#17394c')
fig.text(.055, .89, 'Simulation contact data are transformed into each sensor frame, then distributed over the vendor point coordinates.',
fontsize=12, color='#496278')
fig.text(.055, .035, 'Reference: OpenTac separates contact mechanics and sensor readout. This implementation uses a separate, uncalibrated model.\n'
'No continuous elastic layer, magnetic field, Hall electronics or measured hardware accuracy is simulated.', fontsize=10, color='#496278')
fig.savefig(OUTPUT / 'm3025_contact_method.png')
plt.close(fig)
fig, axes = plt.subplots(3, 4, figsize=(12, 10), dpi=160, sharex=True, sharey=True)
for row, engine in enumerate(['mujoco', 'physx', 'newton']):
d = np.load(ROOT / 'validation/tactile' / f'gripper_{engine}.npz')
for column, target in enumerate([.2, 1.95, 2.8, 4.1]):
sample = np.argmin(abs(d['time_s'] - target))
ax = axes[row, column]
sc = ax.scatter(points[:, 0], points[:, 1], c=d['normal_compression_n'][sample, 0], s=45,
cmap='viridis', vmin=0, vmax=.4, edgecolors='#556677', lw=.25)
ax.set_aspect('equal')
if row == 0:
ax.set_title(['Open', 'Hold contact', 'After translation', 'Released'][column])
if column == 0:
ax.set_ylabel(engine+'\nSensor y (mm)')
if row == 2:
ax.set_xlabel('Sensor x (mm)')
ax.text(.03, .97, f"{d['time_s'][sample]:.3f} s", transform=ax.transAxes, va='top', fontsize=9,
bbox={'facecolor':'white','alpha':.85,'edgecolor':'none','pad':1})
fig.subplots_adjust(right=.89, top=.9, bottom=.08, wspace=.28, hspace=.25)
cax = fig.add_axes([.92, .2, .013, .55])
fig.colorbar(sc, cax=cax, label='Local compression (N); values above 0.4 N use the top colour', extend='max')
fig.suptitle('Left M3025 array: unfiltered recorded force distributions\nSame 77 vendor positions and colour scale in all three environments', fontsize=15)
fig.savefig(OUTPUT / 'gripper_three_environment_sequence.png')
plt.close(fig)
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