Technologies in Robotic Systems

Tactile Sensor Systems

Pressure Distribution Sensing

Modeled after humans’ sense of touch, tactile sensor systems enable certain technical elements to perceive mechanical contact. This makes it possible to sense both isolated contact and pressure distributed over a large-area with a spatial resolution. Its use in technical systems is opening novel approaches to human-machine interaction, system safety and process monitoring. Potential fields of use cover a multitude of different sectors and range from classic industrial automation to advanced robot applications and even medical technology.

The Fraunhofer IFF develops and builds customized tactile sensor systems. Our range of services extends from simple prototypes to complex sensor systems including electronics and software. Below is an overview of our sensor technology, possible fields of application and reference projects.

Sensor Technology

The heart of the tactile sensor­ systems developed at the Fraunhofer IFF is transducers based on piezoresistive polymer composites. The thusly implemented principle of resistive measurement in combination with a patented matrix design measures pressure distributions spatially resolved. Highly flexible contact materials assure high ruggedness and durability. Smart sensor electronics ensure that the transducers sense rapidly and reliably. Depending on the use, the sensor can be integrated separately or directly in the transducers. Various communication interfaces or even switching outputs are available to integrate the system.

Versatility

The tactile transducers’ shape, size and resolution can be modified for any application. Advanced manufacturing methods make it possible to shape them freely and thus even produce complexly curved or flexible transducers. A variety of shell materials are available to adapt them to the particular conditions of use. In addition to especially rugged designs, waterproof, breathable or shock-absorbing transducers can also be produced.

High Safety

Since the reliability and control of the sensor function are crucial especially in safety applications, the tactile sensor system can be equipped with a fail-safe circuit. Thus, every single sensor cell’s operation can be monitored. In addition, the sensor system, used as a collision sensor, effectively reduces the risk of injury through the use of shock-absorbing shell materials and is thus instrumental in personal safety. The use of rugged materials assures high durability. More than 50 million switching cycles have been attained in long-time tests.

Projects

 

Tactile Sensor Systems for Safe Collision Detection

Tactile sensor systems are a key technology for detecting collision and limiting contact forces in applications that allow humans and robots to interact directly.
 

Tactile Sensor Systems in Pressure-sensitive Flooring

Tactile sensor systems integrated in flooring measure forces acting on it with a spatial resolution. Thusly outfitted flooring detects both stationary and moving objects.

 

Tactile Sensor Systems for Sensitive Gripping

Object handling is one of the key tasks in industrial and service robotics. The applied grippers are mostly adapted to the geometry of the object to be gripped.
 

Tactile Sensor Systems as User Interfaces

Tactile sensor systems applied as a pressure-sensitive skin to the surface of robots or other moving machine parts cannot only be used for safe collision detection, but also as user interfaces.

Further Fields of Application

  • Measurement systems for pressure distribution sensing
  • Medical technoogy
    • Gait analysis (pressure sensing in shoes, rolling, and the like)
    • Medical bedding systems (decubitus ulcer prophylaxis)
    • Pressure sensing on prosthetics
    • Seating comfort measurement
  • Automotive engineering
    • Vehicle passenger detection
    • Seating comfort measurements
    • Pressure-sensitive surfaces
  • Virtual and augmented reality
    • Tangible interfaces
    • Haptic interfaces