Monitoring Mechanical Motion

In this example SensorPlot™ was used to monitor the position of a linear actuator during a commanded move of 2.3 inches in 0.5 seconds. The quick 2.3" move was compared to the theoretical position profile which was computed mathematically using the real-time math capabilities of the SensorPlot™. The acceleration profile of the linear actuator is shown below:

The Measurement

SensorPlot™ was connected to the encoder attached to the servo motor driving the linear actuator and configured to acquire a measurement every 200uS for 0.5 seconds. To synchronize the acquisition of data with the movement of the linear actuator, SensorPlot™ was set up to begin acquiring data on the first commanded movement of the servo motor. The linear actuator was programmed to move 2.3" in 0.5 seconds and a single block of data was acquired.

Comments

• The theoretical position of the linear actuator was derived by computing the double integral of the theoretical acceleration. SensorPlot™ supports differentiation and integration in addition to numerous standard math operations.
• As indicated by the graph titled Linear Actuator Position Error the actuator experienced a 40 mil deviation from ideal during the 2.3" move. The error was computed by simply creating a trace that subtracted the measured position from the mathematically computed position.

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