Angular Acceleration
Performance specifications determine the maximum speed at which a precision motion platform can change its rotational velocity. A rate table slew rate is measured in degrees per second squared and determines how quickly the platform reaches its commanded speed.
Motion Profile
Achieving a high rate table slew rate requires powerful motors and high-current amplifiers to overcome the inertia of the platform and the payload. The control system must manage the ramp-up phases to prevent overshoot or oscillation. Smooth transitions are necessary to ensure that the sensor under test does not experience unmodeled shocks.
Trapezoidal profiles are often used to minimize mechanical wear during high-acceleration tests.
Control Precision
Precise encoders monitor the position and velocity in real time to maintain the accuracy of the motion. Any lag in the feedback loop will degrade the effective rate table slew rate. High-end systems use direct-drive motors to eliminate the backlash and friction associated with gearboxes.
Testing Constraint
Limitations in this parameter restrict the types of maneuvers that can be simulated in the laboratory. If the required acceleration exceeds the machine capability, the test results will not accurately represent flight conditions. Verification of the rate table slew rate is performed during annual calibration using external reference sensors.
