AN INVESTIGATION OF NOVEL HIGH-SPEED ACTUATORS FOR SOFT PRODUCT ASSEMBLY AND MANIPULATION

With the ever increasing need for performance equipment emphasis is placed on producing individual components which can fulfil the necessary criteria. In the field of pneumatics high-speed components are scarce. Many traditional forms of actuation (e.g. solenoids) are now competing with new forms of actuator based on novel materials to produce a high-speed actuation. Coupled with this is the need for a low-cost and compact components. This research programme tackles the problem of producing a high-speed pneumatic valve. The initial objective is to achieve a total response time (full opening and closing of the valve) of 3ms or less. In addition the valve must have a minimum bandwidth of 1OOHz, a minimum lifespan of 10 cycles and cost approximately £40. The work involves an investigation of three forms of actuation ranging from well-developed and tested formats to the newest of rare earth materials. Through a theoretical analysis, simulation and experiments the three actuator alternatives are evaluated. From this material a valve designed to meet the requirements emerges. The first form of actuation considered was the solenoid. For this evaluation two high performance commercial valves are tested to determine the response time, bandwidth and pressure drop. Results showed that the solenoid valves do not have the potential to operate as high-speed components. Additionally they have a low bandwidth and a high pressure drop. The second form of actuation considered was a magnetostrictive material, Terfenol-D. Designed to produce a high deflection from an applied magnetic field the Terfenol-D actuator is a relative newcomer to the field of high-speed actuation. The main test performed on this material is the building of the rig required to produce the prerequisite deformation. Results from this simulation suggest that the process involved is complex and the resulting actuator will be bulky and expensive. The final form of actuation considered was a piezoceramic bimorph. Similar in principle to the magnetostrictive material the piezoceramic bimorph deflects due to an applied voltage. The bandwidth of the bimorph is high and the relative cost of the material low. From the results of simulation and experiments the piezoceramic bimorph was chosen as the actuator for the high-speed valve. The valve designed around the bimorph applies a basic principle of releasing pulses of air from a ‘reservoir’. Tests performed on the valve design returned a response time less than 3ms, a bandwidth greater than lOOHz and a 90% pressure drop. In addition the lifetime of the valve exceeds nearly twice the required amount. The valve consists of a minimum number of components and costs approximately the same as a standard off-the-shelf solenoid valve.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

De Montfort University

Year dc:date.issued

1997

Author dc:creator

• Turner, Celine

Licence

• https://dora.dmu.ac.uk/bitstreams/9d7c114d-620f-4542-9a87-6ebe6904f804/download