Design and Implementation of Electrical Stimuli Generator for Structural Measurement System

The Electrical Stimuli Generator is a low-cost, compact, configurable test system developed for Spacecraft Structural Measurement Unit (SMU). The SMU acquires and processes signals from acoustic, vibration, and shock sensors, placed at different locations on the spacecraft body. This test system generates electrical signals(voltage) that simulate the actual sensor outputs. The stimuli range from simple classical signals like sine, half-sine, terminal ramp, etc. to real-time pyrotechnic acceleration-time data, as an analog signal. The frequencies and amplitudes of these stimuli are configurable. The structural events are a one-time occurrence in real scenarios. This calls for a simulator in a design laboratory environment, wherein SMU needs to be tested for full frequency and dynamic range. Vibration machines are not viable in the lab, and ‘commercially off-the-shelf’ stimulator equipment is expensive and not customizable to our needs. This paper presents the design, implementation, and real-time testing of an FPGA-based Electrical stimuli generator for satellite structural measurement unit design.