關節力矩控制和物理引擎屬性
關節力矩控制
vrep中在達到目標速度之前，輸出力矩等於設定的最大力矩
簡單寫法
python 簡潔寫法
def setJointTorque(joint_handle,torque):
self.obj_set_force(joint_handle, torque)
self.obj_set_velocity(joint_handle, self.joints_max_velocity * np.clip(torque, -1, +1))
物理引擎屬性
全局修改和對特定物體的修改
全局的參數不建議修改
要注意的幾個參數
1.Friction 明確說了能產生碰撞的物體之間纔有摩擦力
2.Restution 恢復係數
3.Linear damping: 線性阻尼:線性運動阻尼值，增加線性阻力，增加穩定性。
4.Angular damping 角度阻尼
5.Sticky contact (only Bullet V2.78): when this item is checked, then contact points will be very strong, but might lead to instabilities. It is recommended to keep this disabled. This feature is not needed for Bullet versions after V2.78
粘性
6.Auto-shrink convex mesh和Custom collision margin factor不用管，默認就好
ODE
重要的只有線性阻尼和角度阻尼
Vortex
功能多了一些
1.Adhesive force: generates glue at the contact. 能讓兩個物體產生粘性
Newton
1.Linear drag: a linear drag value, which can improve stability.
2.Angular drag: an angular drag value, which can improve stability
joint 參數
Normal CFM: a constraint force mixing parameter used when away from limits.
Stop CFM: a constraint force mixing parameter at the limits.
超出限位時的阻力
最重要的是Vortex
Joint axis friction關節軸摩擦:允許定義沿着或圍繞約束軸的內摩擦。
和拉力成比例Proportional: if true, friction is proportional to the tension in the constraint.
摩擦係數Coefficient: for proportional friction force, the friction is proportional to the tension * coefficient.