Automatic circulation heat dissipation type linear motor motion control platform and control method thereof

Abstract

The invention relates to an automatic circulation heat dissipation type linear motor motion control platform and a control method thereof. The automatic circulation heat dissipation type linear motormotion control platform comprises an upper computer, a lower computer controller and an automatic circulation heat dissipation device, the lower computer controller comprises a temperature control board card, and the upper computer communicates with the lower computer controller through an RS232 serial port line; the temperature control board card sends a control signal to an electric control valve in the automatic circulation heat dissipation device; a motor temperature sensor is installed in an area with the most obvious temperature heating of the motor rotor of the permanent magnet synchronous linear motor; the automatic circulation heat dissipation device comprises a cooling plate, the cooling plate is assembled on the upper side of the coil winding of the motor rotor in a surface-mounted mode, a cooling pipe is laid on the cooling plate, a cooling liquid inlet is connected with an external cooling liquid supply loop through an electric control valve, and a valve position sensor isarranged on the valve rod of the electric control valve; and the motor temperature sensor and the electric control valve are connected with the temperature control card. The platform solves the heating problem of the motor in different motion states, and the motion precision of the motor is improved.

Description

technical field [0001] The invention belongs to the field of motion platforms and controls, in particular to an automatic circulation heat dissipation linear motor motion control platform and a control method. Background technique [0002] In the current development of the manufacturing industry, the demand for high-performance parts with complex contours is increasing, and the requirements for the performance of CNC machine tools and the control accuracy of the feed motion platform are constantly improving, not only the control accuracy of the motion platform in high-speed situations , It also puts forward higher technical requirements for its stability in high-acceleration occasions caused by frequent start-stop operations at high speed. [0003] Compared with the transmission mode driven by the traditional ball screw + rotary servo motor, the motion platform driven by the linear motor does not include the intermediate transmission link, and the electromagnetic thrust dire...

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Problems solved by technology

[0006] 1. When permanent magnet linear synchronous motors are applied to CNC machine tools or high-speed precision positioning platforms, during the conversion process of electromagnetic energy between the primary and secondary windings, the excitation current passes through the coil windings and generates losses in the coil windings. These The loss is almost all converted into heat energy, and the greater the driving force, the greater the heat generated, which will increase the temperature of the coil. On the one hand, the heating of the coil will cause thermal deformation, increase the stress of the guide rail, and increase the wear of the guide rail during operation. , it will even affect the radial error in severe cases; on the other hand, heating will increase the resistance of the coil and increase the electrical time constant, reducing the response of the system. Once the temperature rise exceeds the limit, it will affect its insulation performance and mechanical strength. Reduce service life, or even damage and malfunction;

[0007] 2. The position of the coil of the existing linear motor-driven motion control platform has poor heat dissipation, which is more likely to cause heat accumulation. In the past, the heat dissipation device simply adopted the centralized cooling method of external heat sinks and fans. By concentrating on the mechanical structure Cooling is used to improve the heat generation of the motor, and its heat dissipation efficiency is not high, and there is no corresponding temperature detection device, and the heat dissipation cannot be dynamically and automatically adjusted according to the actual operating conditions and working conditions, nor does it involve a temperature controller and a real-time cooling control method for automatic cycle heat dissipation , which directly restricts the performance of the excellent characteristics of the linear motor motion platform;

[0008] 3. Regarding the temperature control methods of existing cooling devices in other fields: one is to set a fixed temperature threshold, and when the temperature measured by the sensor is greater than the threshold, the flow rate of the cooling liquid is correspondingly increased, and when the sensor measures the temperature When it is less than the threshold value, the flow rate of the coolant is correspondingly reduced so that its temperature is near the threshold value. The disadvantage of this method is that when the measured temperature fluctuates back and forth near the temperature threshold value, it will cause frequent switching of the valve opening of the electric control valve. The service life of the valve is affected. This type of method has the disadvantages of low control accuracy, rough algorithm, and poor control effect; the other type uses the traditional PID continuous control method, but the temperature control is a large inertia link with a first-order pure lag. The contradiction between control accuracy and dynamic response cannot be resolved, which will cause large oscillations;

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