finding difficult to move the quadruped robot

[AchyuthGS]

Intro

Hi!

I am a graduate student, I use MuJoCo for my research on quadruped robot.

My setup

import mujoco as mj
from mujoco.glfw import glfw
import numpy as np
import os
from curve import bezier_curve
from scipy.spatial.transform import Rotation as R

xml_path = 'quadrap1.xml'
simend = 100 #simulation time
print_camera_config = 0

For callback functions

button_left = False
button_middle = False
button_right = False
lastx = 0
lasty = 0

def quat2euler(quat_mujoco):
#mujocoy quat is constant,x,y,z,
#scipy quaut is x,y,z,constant
quat_scipy = np.array([quat_mujoco[3],quat_mujoco[0],quat_mujoco[1],quat_mujoco[2]])

r = R.from_quat(quat_scipy)
euler = r.as_euler('xyz', degrees=True)

return euler

def init_controller(model,data):
#initialize the controller here. This function is called once, in the beginning
pass

def controller(model, data):
#put the controller here. This function is called inside the simulation.
#pass
data.ctrl[0] = 0
data.ctrl[1] = 0.3
data.ctrl[2] = -0.5
data.ctrl[3] = 0
data.ctrl[4] = 0.3
data.ctrl[5] = -0.5
data.ctrl[6] = 0
data.ctrl[7] = 0.3
data.ctrl[8] = -0.5
data.ctrl[9] = 0
data.ctrl[10] = 0.3
data.ctrl[11] = -0.5

def keyboard(window, key, scancode, act, mods):
if act == glfw.PRESS and key == glfw.KEY_BACKSPACE:
mj.mj_resetData(model, data)
mj.mj_forward(model, data)

def mouse_button(window, button, act, mods):
# update button state
global button_left
global button_middle
global button_right

button_left = (glfw.get_mouse_button(
    window, glfw.MOUSE_BUTTON_LEFT) == glfw.PRESS)
button_middle = (glfw.get_mouse_button(
    window, glfw.MOUSE_BUTTON_MIDDLE) == glfw.PRESS)
button_right = (glfw.get_mouse_button(
    window, glfw.MOUSE_BUTTON_RIGHT) == glfw.PRESS)

# update mouse position
glfw.get_cursor_pos(window)

def mouse_move(window, xpos, ypos):
# compute mouse displacement, save
global lastx
global lasty
global button_left
global button_middle
global button_right

dx = xpos - lastx
dy = ypos - lasty
lastx = xpos
lasty = ypos

# no buttons down: nothing to do
if (not button_left) and (not button_middle) and (not button_right):
    return

# get current window size
width, height = glfw.get_window_size(window)

# get shift key state
PRESS_LEFT_SHIFT = glfw.get_key(
    window, glfw.KEY_LEFT_SHIFT) == glfw.PRESS
PRESS_RIGHT_SHIFT = glfw.get_key(
    window, glfw.KEY_RIGHT_SHIFT) == glfw.PRESS
mod_shift = (PRESS_LEFT_SHIFT or PRESS_RIGHT_SHIFT)

# determine action based on mouse button
if button_right:
    if mod_shift:
        action = mj.mjtMouse.mjMOUSE_MOVE_H
    else:
        action = mj.mjtMouse.mjMOUSE_MOVE_V
elif button_left:
    if mod_shift:
        action = mj.mjtMouse.mjMOUSE_ROTATE_H
    else:
        action = mj.mjtMouse.mjMOUSE_ROTATE_V
else:
    action = mj.mjtMouse.mjMOUSE_ZOOM

mj.mjv_moveCamera(model, action, dx/height,
                  dy/height, scene, cam)

def scroll(window, xoffset, yoffset):
action = mj.mjtMouse.mjMOUSE_ZOOM
mj.mjv_moveCamera(model, action, 0.0, -0.05 *
yoffset, scene, cam)

#get the full path
dirname = os.path.dirname(file)
abspath = os.path.join(dirname + "/" + xml_path)
xml_path = abspath

MuJoCo data structures

model = mj.MjModel.from_xml_path(xml_path) # MuJoCo model
data = mj.MjData(model) # MuJoCo data
cam = mj.MjvCamera() # Abstract camera
opt = mj.MjvOption() # visualization options

Init GLFW, create window, make OpenGL context current, request v-sync

glfw.init()
window = glfw.create_window(1200, 900, "Demo", None, None)
glfw.make_context_current(window)
glfw.swap_interval(1)

initialize visualization data structures

mj.mjv_defaultCamera(cam)
mj.mjv_defaultOption(opt)
scene = mj.MjvScene(model, maxgeom=10000)
context = mj.MjrContext(model, mj.mjtFontScale.mjFONTSCALE_150.value)

install GLFW mouse and keyboard callbacks

glfw.set_key_callback(window, keyboard)
glfw.set_cursor_pos_callback(window, mouse_move)
glfw.set_mouse_button_callback(window, mouse_button)
glfw.set_scroll_callback(window, scroll)

Example on how to set camera configuration

cam.azimuth = 3.5976562500001448 ; cam.elevation = -26.478125000000013 ; cam.distance = 3.4990578128076946
cam.lookat =np.array([ 0.0 , 0.0 , 0.0 ])
#initialize the controller
init_controller(model,data)

data.ctrl[0] = 0
data.ctrl[1] = 0
data.ctrl[2] = 0
data.ctrl[3] = 0
data.ctrl[4] = 0
data.ctrl[5] = 0
data.ctrl[6] = 0
data.ctrl[7] = 0
data.ctrl[8] = 0
data.ctrl[9] = 0
data.ctrl[10] = 0
data.ctrl[11] = 0

#set the controller
mj.set_mjcb_control(controller)

while not glfw.window_should_close(window):
time_prev = data.time

while (data.time - time_prev < 1.0/60.0):
    mj.mj_step(model, data)


#print(data.qpos[0])
#print(data.qpos[1])
#print(data.qpos[2])

quat = np.array([data.qpos[3], data.qpos[0], data.qpos[1], data.qpos[2]])
euler = quat2euler(quat)
print('pitch = ',euler[1]);


if (data.time>=simend):
    break;

# get framebuffer viewport
viewport_width, viewport_height = glfw.get_framebuffer_size(
    window)
viewport = mj.MjrRect(0, 0, viewport_width, viewport_height)

#print camera configuration (help to initialize the view)
if (print_camera_config==1):
    print('cam.azimuth =',cam.azimuth,';','cam.elevation =',cam.elevation,';','cam.distance = ',cam.distance)
    print('cam.lookat =np.array([',cam.lookat[0],',',cam.lookat[1],',',cam.lookat[2],'])')

# Update scene and render
mj.mjv_updateScene(model, data, opt, None, cam,
                   mj.mjtCatBit.mjCAT_ALL.value, scene)
mj.mjr_render(viewport, scene, context)

# swap OpenGL buffers (blocking call due to v-sync)
glfw.swap_buffers(window)

# process pending GUI events, call GLFW callbacks
glfw.poll_events()

glfw.terminate()

My question

i am able to control the joints of the bot but unable to move that. i am unable to figure it out how the controller should be setup

Minimal model and/or code that explain my question

No response

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.