An adaptive m/t speed measuring system based on fpga

Abstract

The invention provides an adaptive M / T speed measurement system based on FPGA, including FPGA, resolver decoding chip and resolver; the control signal output by the FPGA is transmitted to the resolver decoding chip, and the resolver decoding chip will excite the magnet The signal is transmitted to the resolver; the resolver returns the collected angle signal to the resolver decoding chip, and returns to the FPGA after being decoded by the resolver decoding chip. The frequency multiplication processing of the signal pulse at low speed of the invention makes the low-speed measurement accuracy of the system higher, and the minimum speed that can be measured can reach 0.2r / min without changing the resolution of the speed measuring sensor; The frequency division processing enables the algorithm to measure a higher motor speed under the condition that the word length of the computer remains unchanged and does not overflow, so as to ensure the measurement accuracy at high speed; the update cycle of the speed loop can be reduced to 400μs, which is suitable for high-performance servo systems. It can effectively solve the contradiction between frequency response and overshoot, and widen the range of speed regulation.

Description

technical field [0001] The invention relates to a measurement system applied in a position servo system to ensure speed measurement accuracy under high and low speed conditions, in particular to an FPGA-based self-adaptive M / T speed measurement system. Background technique [0002] The current speed measurement technology mainly includes M method speed measurement, T method speed measurement, and M / T method speed measurement. [0003] (1) M method speed measurement is to measure the number M of pulses output by the rotary encoder within a certain period of time T to calculate the average rotational speed during this period. When M is large at high speed, the quantization error is small, and at low speed, the error increases. This method is only applicable to high-speed section. [0004] (2) The T method of speed measurement is to use a counter to count the high-frequency pulses of known frequency within the interval between two adjacent pulses, so as to calculate the speed,...

AI Technical Summary

Problems solved by technology

At high speed, M is large, the quantization error is small, and at low speed, the error increases. This method is only applicable to high speed section

[0004] (2) The T method of speed measurement is to use a counter to count the high-frequency pulses of known frequency within the interval between two adjacent pulses, so as to calculate the speed, the error is small at low speed, and the quantization error increases at high speed. This method is only suitable for low-speed

For a high-performance servo system, the system requires fast response, small overshoot, and large stability margin; usually, a high-speed motor is selected to shorten the response time. If the output frequency of the speed sensor is high during high-speed operation, the maximum speed of the motor will be will be limited; in order to reduce system overshoot and improve system stability, it is necessary to control the motor shaft speed within a very low range, the low-speed measurement accuracy of the motor is very important, and its low-speed measurement accuracy is limited by high pulse frequency

Images