Mujoco-小球建模与控制

原创

已于 2022-02-09 17:22:48 修改 · 1.8k 阅读

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CC 4.0 BY-SA版权

文章标签：

#Mujoco

于 2022-02-08 20:42:31 首次发布

视频教程：

https://www.bilibili.com/video/BV1e44y1H7Mn/

资源请到tiny.cc/mujoco下载

涉及内容

本次课程制作了一个简单的小球模型,然后对小球进行简单的模拟，并演示了一些参数的作用。

小球模型：

<mujoco>
  <worldbody>
        <light diffuse=".5 .5 .5" pos="0 0 3" dir="0 0 -1"/>
    <geom type="plane" size="10 1 0.1" rgba=".9 0 0 1"/>
    <body pos="0 0 1">
      <joint type="free"/>
      <geom type="sphere" size=".1" rgba="0 .9 0 1"/>
    </body>
  </worldbody>
</mujoco>

然后通过c代码来演示相机的一些设置，小球位置和速度的设置,给小球施drag force等，c代码如下：



#include<stdbool.h> //for bool
//#include<unistd.h> //for usleep
#include<math.h>

#include "mujoco.h"
#include "glfw3.h"
#include "stdio.h"
#include "stdlib.h"
#include "string.h"


char filename[] = "../myproject/projectile/ball.xml";

// MuJoCo data structures
mjModel* m = NULL;                  // MuJoCo model
mjData* d = NULL;                   // MuJoCo data
mjvCamera cam;                      // abstract camera
mjvOption opt;                      // visualization options
mjvScene scn;                       // abstract scene
mjrContext con;                     // custom GPU context

// mouse interaction
bool button_left = false;
bool button_middle = false;
bool button_right =  false;
double lastx = 0;
double lasty = 0;

// holders of one step history of time and position to calculate dertivatives
mjtNum position_history = 0;
mjtNum previous_time = 0;

// controller related variables
float_t ctrl_update_freq = 100;
mjtNum last_update = 0.0;
mjtNum ctrl;

// keyboard callback
void keyboard(GLFWwindow* window, int key, int scancode, int act, int mods)
{
   
   
    // backspace: reset simulation
    if( act==GLFW_PRESS && key==GLFW_KEY_BACKSPACE )
    {
   
   
        mj_resetData(m, d);
        mj_forward(m, d);
    }
}

// mouse button callback
void mouse_button(GLFWwindow* window, int button, int act, int mods)
{
   
   
    // update button state
    button_left =   (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_LEFT)==GLFW_PRESS);
    button_middle = (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_MIDDLE)==GLFW_PRESS);
    button_right =  (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_RIGHT)==GLFW_PRESS);

    // update mouse position
    glfwGetCursorPos(window, &lastx, &lasty);
}


// mouse move callback
void mouse_move(GLFWwindow* window, double xpos, double ypos)