Comparison of friction measurement between load/unload ramps and suspension lift tabs using strain gage and actuator current

Friction force between the load/unload ramp and suspension is measured and compared using two different methods. One method uses a well-known technique utilizing strain gages, which is similar to the method used to measure stiction and friction during contact-start-stop. The other method involves measuring the required actuator current to move the suspension across the load/unload ramp. In this paper we show that the actuator measurement can accurately predict the friction force between the ramp and the suspension on certain regions of the ramp.