simSetThreadSwitchTiming(2)

simDelegateChildScriptExecution()
lm=simGetObjectHandle('left_motor')
rm=simGetObjectHandle('right_motor')
while (simGetSimulationState()~=sim_simulation_advancing_abouttostop) do
   simSetJointTargetVelocity(lm,-0.9)
    simSetJointTargetVelocity(rm,1)
end