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Control method for improving low-speed performance of electric forklift based on improved M/T method

A technology of electric forklift and control method, which is applied in the direction of low-speed motor control, electric vehicle, motor parameter estimation/correction, etc., can solve the problems of speed closed-loop influence, influence of speed measurement accuracy, poor customer experience, etc.

Active Publication Date: 2020-04-17
河南嘉晨智能控制股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, at low speeds, it will greatly affect the speed measurement accuracy
At this time, the speed closed loop will have a greater impact
In the speed closed-loop process, low-speed control may cause vehicle vibration problems, such as unstable starting and poor customer experience

Method used

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  • Control method for improving low-speed performance of electric forklift based on improved M/T method
  • Control method for improving low-speed performance of electric forklift based on improved M/T method
  • Control method for improving low-speed performance of electric forklift based on improved M/T method

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Embodiment Construction

[0019] The said M / T method of the present invention is a kind of velocity measuring method. It adds a capture port on the basis of the M method, and switches to use the T method to measure the motor speed when appropriate.

[0020] see figure 2 , Electric forklift manufacturers supporting incremental encoder with A phase and B phase, the incremental encoder is generally installed on the rotor, the motor rotor rotates a circle will generate a square wave on the A channel and B channel. When the number of motor stages is 1 and the number of encoder lines is 80, 80 square wave pulses will be generated on phase A and phase B respectively in one revolution. Then each pulse corresponds to 360 / 80 degrees. Then the electrical angle of the rotor is also 360 / 80 degrees. The stator electrical angle is the rotor electrical angle plus the slip angle. refer to image 3 Schematic diagram of stator electrical angle calculation. The current existing method is to use the encoder interface...

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Abstract

The invention discloses a control method for improving the low-speed performance of an electric forklift based on an improved M / T method. In an encoder speed detection link, the rotor speed of a motoris collected by adopting fixed time, that is, an M method is adopted to meet medium-high speed sampling precision, and a T method is used to collect the low-speed speed of the motor at proper time. Due to the adoption of the M / T method, the precision of the stator angle is improved. Especially under the conditions of low speed and large current, the waveform quality is improved due to a high stator angle, the speed control precision is improved without using too high bandwidth, and the problem of jittering during starting or low-speed operation is relieved.

Description

technical field [0001] The invention relates to a control method for improving the low-speed performance of an electric forklift based on an improved M / T method. Background technique [0002] Electric forklifts have a wide range of speed regulation during actual use. From -6000RPM to 6000RPM. Electric forklifts need to do some fine displacement movements in the warehouse, and the speed is generally lower than 0.1Km / h. When transporting goods over long distances between warehouses, the speed will reach 20Km / h. When the electric forklift is running at low speed, it is prone to vehicle vibration. The main reasons for this problem are: [0003] Conventional speed measurement is related to the selected encoder type. At present, the supporting encoders of electric forklift manufacturers often use low-resolution incremental encoders. The speed measurement method mostly uses M method or T method. The T method is used to measure the time difference between 2 consecutive pulses ...

Claims

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Application Information

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IPC IPC(8): H02P23/03H02P23/14B60L15/20
CPCB60L15/20B60L2200/42H02P23/03H02P23/14Y02T10/64Y02T10/72
Inventor 李飞姚欣
Owner 河南嘉晨智能控制股份有限公司
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