An electro-hydraulic copying system which is similar to the mechanical hydraulic copying system is developed and its performance is experimentally investigated. This system has a basic difference in that the stylus movement is converted into an electrical signal via a position transducer and that the actuator displacement is also measured by a position sensing element, which serves as a feedback signal. The performance characteristics such as the percentage overshoot, rise time, settling time, and the steady state error are experimentally obtained under the variation of the system variables, using step, ramp, and sinusoidal inputs. The system parameters include the supply pressure, servo amplifier gain, and feedback gain.
To evaluate the cutting performance of this system, actual cutting test is performed by varying the depth of cut, tool feed velocity, and spindle speed. The cutting results show that the performance of the developed system is superior to that of the conventionally used mechanical type of hydraulic copying system.
