| Description |
In gear driven high accuracy positioners (antennas, teloscope mounts, some robots, etc...) on axis position data is collected from one sensor (synchro, resolver, encoder, etc..) mounted on axis and velocity data is collected from another sensor (tach, resolver RDC, encoder, etc...) mounted on the actuator. The scaling, aka tach gradient, between the measured velocity and the on axis velocity is determined by gear ratio, sensor characteristics (ie tach Kt), measurement scaling (ie at ADC or RDC), and software. Although it is possible to predetermine the tach gradient, it is often necessary to measure the tach gradient to confirm design expectations during installation and test. During installation and testing is also often necessary to measure on axis velocity and acceleration to confirm the design goals are met.
Assuming that the on axis sensor is calibrated seperately, it is possible to use this sensor, during large steps, to measure the tach gradient, velocity and acceleration. Large steps are defined as steps large enough to allow the axis to accelerate to full velocity and to maintain full velocity for a short time.
This function estimates the tach gradient, on axis velocity and acceleration when a large step is taken and time, command, on axis position, and non-on axis velocity are recorded.
This function is primarily intended to analyze measured data but can also be used on simulation results. |
