Rotate speed and differential measurement method without velocity metre

Abstract

The invention relates to a method for measuring rotary and differential speed without a velocity metre, which is characterized in that signals collected by sensors on a rotary drum and a rotor are directly input into a Rockwell MicroLogix1500 PLC processor provided with high-speed counters and then are output into a touch display screen by the PLC processor provided with the two high-speed counters of HSC0 and HSC1; and an impulse method is used for measuring the rotary speed of a high-speed section, and a periodic method is used for measuring the rotary speed of a low-speed section. As the PLC processor provided with the high-speed counters replaces the velocity metre and has the function of speed measurement of the velocity metre, the PLC processor is in charge of the routine control of a system, the potentiality of the PLC processor is fully tapped, and the PLC processor also has the function of speed measurement. The strong programming instruction, the timer interruption call function and the high programming flexibility of PLC are utilized, the impulse method which controls the high-speed section and the periodic method which controls the low-speed section are respectively used for measuring the speed, and the high-speed and the low-speed sections can have favorable accuracy of speed measurement and stability.

Description

technical field [0001] The invention relates to a method for measuring a counter, in particular to a method for simultaneously measuring the rotating speed and the differential speed. Background technique [0002] In the case where there are two rotating bodies rotating coaxially and in the same direction and are closely related to each other, it is often necessary to measure the speed of one of the rotating bodies and at the same time measure the speed difference between the two rotating bodies (hereinafter referred to as the differential speed) . [0003] For example, centrifuges, which are widely used in sewage treatment systems, need to measure the rotational speed of their drum and the differential speed between the drum and the rotor. (See Figure 4 ) [0004] Figure 4 A typical example of this type of speed measurement is given. PLC is mainly responsible for the control of the whole system, which uses speed and differential speed. At the measuring part of the dru...

AI Technical Summary

Problems solved by technology

This creates a problem, that is, the data displayed on the tachometer and the data displayed on the touch screen are always inconsistent. The accuracy will drop once every time, coupled with the insurmountable drift of the analog value, etc., eventually resulting in the inconsistency of the two displayed data

[0006] In addition, there is another fatal weakness. According to the principle of pulse speed measurement, the more pulses measured in a unit time, the higher the speed measurement accuracy.

In other words, this kind of tachometer is suitable for high-speed use, such as 2000 rpm or higher, and it is powerless for low speeds of only tens to hundreds of rpm, and it will be unusable due to violent data jumps in low-speed segments

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