Sensory feedback system for electroactive polymer based transducers

Abstract

A system for obtaining inline sensory feedback from an electroactive polymer based transducer for use in feedback control applications is disclosed. Specifically a method of obtaining sensory feedback from an electroactive polymer based transducer includes the steps of: receiving a user input in a control system, combining it with a control system feedback signal from a sensory feedback circuitry and producing a control signal; receiving the control signal in an amplifier and sensory tone generator, combining it with an amplifier feedback signal from the sensory feedback circuitry and producing a power signal; receiving the power signal and an environmental disturbance in an electroactive polymer transducer and sensory circuitry and responsive to the user input producing a sensory signal; receiving the sensory signal in the sensory feedback circuitry and producing the control system feedback signal and the amplifier feedback signal; and producing a data output in the control system.

Description

FIELD OF INVENTION [0001] The present invention relates generally to an electroactive polymer based transducers and in particular electroactive polymer based transducers for use in inline sensory feedback and control system applications. BACKGROUND OF THE INVENTION [0002] Position and force feedback are crucial requirements for high performance industrial and consumer based control applications. Such applications Include micro and nano positioning, human interactive robotics, multi-agent robotics, toys, soft tissue handling and animatronics. [0003] Traditional transducers include AC and DC motors, pneumatic, solenoid and hydraulic actuators. Sensory feedback from traditional transducers is commonly provided by additional components such as strain gages, accelerometers, laser interferometers, encoders, potentiometers, LVDTs, pressure sensors, load cells, and additional electroactive sensors. Each of these components requires extra power and signal recovery circuitry. Furthermore, in ...

AI Technical Summary

Benefits of technology

[0011] The system responsible for making the foregoing measurements from an electroactive polymer transducer is comprised of an amplifying stage, a sensory feedback stage and a control stage. The amplifying stage includes a means by which to add the sensory signal to the control signal and provides power to the electroactive polymer transducer during operation. It also includes provision for an internal feedback control loop to improve the performance of the amplifying stage in supplying energy to the electroactive polymer transducer. The sensory feedback stage includes circuitry for obtaining the feedback signals from the electroactive polymer transducer with and without the presence of the control signal. It also comprises signal conditioning circuitry, control / sensory signal separation circuitry, electrical property message extraction circuitry, and transient surge protection circuitry. The control stage comprises a computer, microcontroller or programmable logic circuit capable of extracting the strain state information from the sensory feedback system with the assistance of a predetermined algorithm. Finally, the control stage also generates suitable control signals from the sensory signals obtained by the sensory stage with provision for user defined or pre-programmed commands.

Problems solved by technology

Furthermore, in space critical applications, the additional components commonly used to provide sensory feedback can interfere with the motion of the transducer and inhibit adequate operation of the device.

In applications involving electroactive polymer transducers, the traditional approach to obtaining sensory feedback by addition of sensory components is cumbersome and with large strain transducers some methods of obtaining feedback are seemingly impossible to implement.

Furthermore, the addition of sensory elements to the transducer compromises the compact quality of electroactive polymer based devices that primarily attracts designers to these materials.

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