DC motor speed control system and speed detection method thereof

Abstract

The invention provides a DC motor speed control system. The DC motor speed control system comprises a brush DC motor, a power supply, a current-voltage converter, a filter amplification circuit, a shaping device and a microprocessor, wherein the brush DC motor is arranged on a wheelchair, the power supply is used for providing power for the brush DC motor, the current-voltage converter is connected with the brush DC motor and is used for converting a pulse current flowing through the brush DC motor to a pulse voltage, the filter amplification circuit is connected with the current-voltage converter and is used for filtering and amplifying the pulse voltage, the shaping device is connected with the filter amplification circuit and is used for shaping the pulse voltage subjected to filtering and amplification to a square wave, the microprocessor is provided with a speed measurement unit and a speed regulation unit, the speed measurement unit is connected with the shaping device and is used for capturing the square wave to obtain a pulse frequency and calculating a rotational speed of the brush DC motor according to the pulse frequency and a preset rule, and the speed regulation unit is connected with the brush DC motor and is used for adjusting the rotational speed of the brush DC motor so as to further regulate a travelling speed of the wheelchair. The invention also provides a speed detection method for the DC motor speed control system.

Description

technical field [0001] The invention relates to a DC motor speed regulation control system and a speed detection method thereof. Background technique [0002] In the DC motor speed control system, the method of speed closed-loop control is generally used to improve the static performance and dynamic performance of the system. The premise of the speed closed loop is the detection of the speed. At present, the method of detecting the speed is mainly realized by using a centrifugal tachometer, a flash speedometer, and a photoelectric digital tachometer. [0003] The centrifugal tachometer is mainly composed of a centrifuge, a transmission, and an indicating dial, among which most of the centrifuges use a heavy hammer structure. In the process of speed detection, not only the heavy hammer is easily affected by the bumps of the ground, resulting in a certain error in the detected speed; but also the uneven scale of the indicator dial will also lead to inaccurate display and read...

AI Technical Summary

Problems solved by technology

In the process of speed detection, not only the heavy hammer is easily affected by the bumps of the ground, resulting in a certain error in the detected speed; but also the uneven scale of the indicator dial will also lead to inaccurate display and reading of the speed; the flash speedometer is based on the instrument When the flash frequency is equal to the rotational frequency of the measured object, the flash frequency is the rotational speed of the measured object, but when the light source of the instrument is blocked, it will affect the accuracy of the speed measurement; the photoelectric digital tachometer uses photoelectric sensitive elements to measure and instrument showing speed

However, when the weather is bad, it will affect the working accuracy of the photoelectric sensor, resulting in the error of speed detection

[0004] In addition, most of these detection devices need to be fixed at special positions, which are additional speed detection devices installed on the wheelchair, which not only increases the production cost, but also increases the structural complexity of the wheelchair, which brings inconvenience to the user. burden

Images