test for knee joint limits under position control

examples/pybullet/examples/humanoid_knee_position_control.py

@@ -0,0 +1,37 @@
+import pybullet as p
+import time
+
+cid = p.connect(p.SHARED_MEMORY)
+if (cid<0):
+	cid = p.connect(p.GUI)
+
+p.resetSimulation()
+
+useRealTime = 0
+
+p.setRealTimeSimulation(useRealTime)
+
+p.setGravity(0,0,0)
+
+p.loadURDF("plane.urdf")
+
+obUids = p.loadMJCF("mjcf/humanoid_fixed.xml")
+human = obUids[0]
+
+
+
+for i in range (p.getNumJoints(human)):
+	p.setJointMotorControl2(human,i,p.POSITION_CONTROL,targetPosition=0,force=50)
+
+kneeAngleTargetId = p.addUserDebugParameter("kneeAngle",-4,4,-1)
+maxForceId = p.addUserDebugParameter("maxForce",0,100,10)
+
+kneeJointIndex=11
+
+while (1):
+	time.sleep(0.01)
+	kneeAngleTarget = p.readUserDebugParameter(kneeAngleTargetId)
+	maxForce = p.readUserDebugParameter(maxForceId)
+	p.setJointMotorControl2(human,kneeJointIndex,p.POSITION_CONTROL,targetPosition=kneeAngleTarget,force=maxForce)
+	if (useRealTime==0):
+		p.stepSimulation()