The Touch Robot responds to gentle pushes without the need for costly and fragile force sensors. Here, the robot’s motor torques are commanded to only compensate for gravity and friction.
What makes the Touch Robot different?
It was built to work like a person- using force and touch to achieve consistent results despite variability in the work. Manufacturing robots today are very powerful and can replicate motions precisely, but because of this they cannot handle parts that are not exact duplicates to the previous. The need to feed the robot completely identical pieces is eliminated by the Touch Robot because the robot determines how to handle the variances in each part.
How does it do this?
The Touch Robot succeeds by combining the precision of a machine with the dynamics of the human arm. With its light-weight structure, low friction joints, and perfectly smooth actuation, arm tension and force can be precisely controlled to maintain desired contact pressure, regardless of variation in workpiece location. While it works, it compares measured geometry with a CAD reference. It then autonomously generates tool paths and forces to match the measured geometry to the desired. This unique, closed-loop operation produces consistent, quality results even with variation in work requirements and material removal tool performance. Through self-acquired measurements using the cutting tool as the probe, the precision of machining will be much better than the uncertainty and variation of the initial part geometry!
Why can’t standard robots do this?
Conventional robots, like most programmable machines, are position controlled, blindly using all available power to reach their goal. Unplanned contact (a “crash”) can generate dangerous forces, so part shape, placement, and tooling must be precise and repeatable, and people must be separated from the work area for their own safety. A way to combat these issues would be to use force sensors- but force sensors do not offer safety and produce sluggish performance (as a result of closing around position loops). The laws of physics prevent a robot with heavy links from ever having a light touch, thus, conventional robots are unable to machine in the way the Touch Robot can.