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  orange box Advanced Tele-robotic interface with real time joystick control
The Challenge
1-Robot Kinematics & Visualization 2-Real Time Path Modification w/jstck 3-New path monitoring/verification

The US Government wished to employ a commercial off-the-shelf industrial robot in an tele-operation application. The task required the robot to perform loading operations remotely under joystick control. Due to economies of scale, industrial robots are more cost effective than custom tele-robotic systems. However, the standard control software on industrial robots are not well suited for tele-robotic applications. 

ACG solution

ACG's Real Time Operating System (RTOS) extensions generated smooth path alteration data in real time from a generalized "force" sensor. The path alteration behavior is akin to a force being superimposed on the robot and robot motion is altered to comply with the "force". The "force" sensor could be a joystick, a mouse or a 6 DOF hand controller. 
The real time path alteration software was integrated with an intuitive interface that enables users to preview motions, check for joint limits and work envelope conditions. The interface also shows an animation of a set of proposed motions, bounding box collision detection and path traces. If desired, the robot model can be made to follow the real robot, as it moves. 

A spring mass damper model is applied to external inputs to provide smooth and stable robot response. The spring mass and damper constants are adaptively modified based on the pressure applied to the joystick and the speed of motion of the hand. The system was thus proactive, based on interpreted urgency, without being over-reactive at other times.  At all times, the robot system would also be monitoring its force and vision sensors in order to avoid obstacle collisions. 

The overall system response was thus both autonomous and supervised. We refer to this superimposed behavior as supervised autonomy. 
Under supervised autonomy, sensors over-ride operator commands in case the commands could result in damage to the robot, work piece or operator.  Visual feedback in the form of blocks were drawn on the robot animation screen - which also modeled coarse robot trajectories to avoid obstacles was developed to aid the operator in understanding why the robot was not "obeying" him- as when the robot one of the robot joints would hit the obstacle if the robot was moved.
Fine motion trajectory was executed by a potential field path planner, driven in part by force and range sensor data.  


Intuitive interfaces to robots make them easier to use. Motion Visualization tools are especially important in telerobotic applications where the operator may need to preview motions to ensure all motions are feasible. Since the robot model uses exactly the same trajectory generator as the actual robot, what you see and truly what you get. Additionally, the interfaces to joystick and hand controllers capture some aspects of operator intent and simplify real time robot control.