Hello,

I have a car whose front wheel are connected to chassis in this manner :

<joint name="wheel_front_left_steer_spin" type="universal">
  <parent>chassis</parent>
  <child>wheel_front_left</child>
  <axis>
    <xyz>0 -1 0</xyz>
    <limit>
      <lower>-0.5235987755982988</lower>
      <upper>0.5235987755982988</upper>
    </limit>
  </axis>
  <axis2>
    <xyz>0 0 1</xyz>
  </axis2>
</joint>

In order to steer my car, I want to set the position around axis2 to 30 degrees. So I tried this (inside my plugin):

 this->joint_ = model_->GetJoint("car::wheel_front_left_steer_spin");

 this->steer_pid_ = common::PID(0.1, 0, 0);

 this->model_->GetJointController()->SetPositionPID(joint_->GetScopedName(), steer_pid_);

 double position = -3.14159265 / 6;
 this->model_->GetJointController()->SetVelocityTarget(joint_->GetScopedName(), position);

But it sends my car bouncing and jumping uncontrollably. So how do I set the angle of my wheels? I haven't found clear examples and couldn't figure it out from the doc.

Thanks in advance,

---

EDIT: So I split my joint into two revolute joints, but can only get one moving at a time. How can I link the two so I keep the 2 degrees of freedom?

<joint name="wheel_front_right_steer" type="revolute">
    <parent>chassis</parent>
    <child>wheel_front_right_steer_link</child>
    <axis>
        <xyz>0 -1 0</xyz>
        <limit>
            <lower>-0.5235987755982988</lower>
            <upper>0.5235987755982988</upper>
        </limit>
    </axis>
</joint>

<link name="wheel_front_right_steer_link">
     <!-- Not sure what to put here -->
</link>

<joint name="wheel_front_right_spin" type="revolute">
    <parent>wheel_front_right_steer_link</parent>
    <child>wheel_front_right</child>
    <axis>
        <xyz>0 0 1</xyz>
    </axis>
</joint>