CN106053872A - Speed measuring instrument based on infrared rays - Google Patents

Abstract

The invention relates to a speed measuring instrument based on infrared rays. The speed measuring instrument includes an infrared ray speed measurement device, the infrared ray speed measurement device includes an infrared ray emitting pipe for emitting infrared rays and an infrared ray receiving pipe for receiving infrared rays, a tooth disc is arranged between the infrared ray emitting pipe and the infrared ray receiving pipe, when the tooth disc rotates, the infrared ray optical path between the infrared ray emitting pipe and the infrared ray receiving pipe is intermittent due to the shielding of the gear teeth, and the signal processing circuit converts the optical signals of the change into electric impulse signals, one pulse signal represents the tooth disc rotating over one tooth. The main controller counts the pulse, and meanwhile, the received pulses in a certain number can be counted by an internal timer, and the rotating speed can be calculated based on the pulse number and the consumed time. The speed measuring instrument based on infrared radiation technology is simple in structure and convenient to install, has less requirement on surrounding environment, and is wide in dynamic measurement scope and high in measurement precision.

Description

Infrared-based tachometer

technical field

The invention relates to a speed measuring instrument based on infrared rays.

scene technology

There are many ways to measure rotor speed, but most are complicated. At present, there are four main types of speedometers for measuring rotational speed: mechanical, electromagnetic, photoelectric and laser. The mechanical type mainly uses the principle of centrifugal force, and drives the free shaft sleeve to move up and down through a fixed mass weight that rotates with the shaft, and the measurement results are obtained according to different rotation speeds corresponding to different shaft sleeve positions. The principle is simple and direct, and no additional electrical equipment is required. Not high, contact speed measurement occasions. The electromagnetic system consists of an electromagnetic sensor and a toothed plate installed on the shaft. The rotation of the main shaft drives the toothed plate to rotate. When the teeth pass through the sensor, the magnetic resistance of the circuit changes. After amplification and shaping, a pulse is formed, and the speed value is obtained through the pulse. Due to the limitations of the machining accuracy of the tooth disc, the minimum resolution interval of the teeth, and the maximum counting frequency of the circuit, the measurement accuracy cannot be guaranteed. The photoelectric structure is similar to the electromagnetic structure. The rotating gear plate is replaced by a photoelectric encoder disk or black and white reflective stripes, and the electromagnetic sensor is replaced by a photoelectric receiver. The measurement results are obtained by counting the reflected light pulse signals. Due to the limitation of the minimum resolution interval of the stripes and the maximum counting frequency of the circuit, the measurement accuracy cannot be guaranteed. The measured rotational speed value is the same as the electromagnetic type, which is the average value of the distance between two counting pulses. Laser velocimetry (LDV) is a speed measurement technology under development. The instantaneous angular velocity of the rotating body is obtained through the laser Doppler effect. Expensive and limited in practical use.

Contents of the invention

The technical problem to be solved by the present invention is to provide a speed measuring instrument based on infrared rays, which has a simple structure, is easy to install, has low environmental requirements, and is easy to complete the measurement of the speed. It has a wide dynamic measurement range and high measurement accuracy.

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an infrared speed measuring instrument is characterized in that it includes an infrared speed measuring device, a signal processing device, a main controller and a display;

The infrared speed measuring device includes an infrared emitting tube for emitting infrared rays and an infrared receiving tube for receiving infrared rays, a gear plate is arranged between the infrared emitting tube and the infrared receiving tube, and the infrared receiving tube outputs an optical signal;

The signal processing device is used to convert the received optical signal output by the infrared receiving tube into an electrical pulse signal;

The main controller is used to receive the electric pulse signal, and calculate the signal to obtain the speed signal;

The display is connected with the main controller for speed display.

Beneficial effects of the present invention: a toothed plate is installed between the infrared emitting tube and the infrared receiving tube. When the toothed plate rotates, due to the shielding of the gear teeth, the infrared optical path between the infrared emitting tube and the infrared receiving tube is intermittent, and the signal processing The circuit converts this changing optical signal into an electrical pulse signal, and a pulse signal means that the gear wheel has rotated a tooth. The main controller counts the pulses, and at the same time receives a certain number of pulses through its internal timer, and can calculate the speed according to the number of pulses and the time used. The rotational speed measuring instrument based on the infrared radiation technology of the present invention has a simple structure, is convenient for installation, has low requirements on the surrounding environment, and can easily complete the measurement of the rotational speed. It has a wide dynamic measurement range and high measurement accuracy.

Further, the main controller is an AT89C52 single-chip microcomputer.

The beneficial effect of adopting the above further solution is: the use of a single-chip microcomputer has low cost and reliable performance.

Further, the signal processing device includes a first resistor R1, the cathode of the infrared emitting tube is grounded, the anode is connected to the collector of the transistor Q1 after being connected in series with the first resistor R1, and the base of the transistor Q1 is connected in series with the sixth resistor The device R6 is connected to the I/O serial port pin P10 of the single-chip microcomputer, and the collector of the triode Q1 is also connected in series with the second resistor R2 to the cathode of the infrared receiving tube, and the anode of the infrared receiving tube is grounded. The cathode of the infrared receiving tube is also connected to the input terminal of the inverter, and the inverting output terminal of the inverter is connected to the first interrupt terminal INT1 of the single-chip microcomputer.

The beneficial effect of adopting the above further scheme is that the circuit structure of the signal processing device is simple and the performance is reliable.

Further, the first data terminal group P00-P07 and the second data terminal group P20-P27 of the single-chip microcomputer are all connected to the signal terminal group of the display.

Further, the display adopts a liquid crystal display module whose model is JHD12864, and the liquid crystal display module adopts a driver chip whose model is HD44780, and a slide for adjusting the contrast of the display is connected in series between the power terminal and the ground terminal of the liquid crystal display module. A rheostat, the sliding end of the sliding rheostat is connected to the contrast adjustment end of the liquid crystal display module.

The beneficial effect of adopting the above-mentioned further scheme is: the model of the driver chip is HD44780, the driver chip has standard interface characteristics, and the operation sequence of the MCS-51 series single-chip microcomputer; the module has 64 bytes of custom character RAM inside, which can be customized for display character. The liquid crystal display module is powered by +5V power supply. There are 20 pins connected to the I/O data port of the single chip microcomputer. The sliding rheostat is used to adjust the contrast of the display. The circuit structure is simple and the installation is relatively convenient.

Description of drawings

Fig. 1 is a schematic diagram of the present invention;

Fig. 2 is a schematic circuit diagram of the present invention.

detailed description

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

As shown in Figure 1, the speed measuring instrument based on infrared includes an infrared speed measuring device, a signal processing device 3, a main controller 4 and a display 5; the infrared speed measuring device includes an infrared emitting tube 1 for emitting infrared rays and a The infrared receiving tube 2 is provided with a gear plate 6 between the infrared emitting tube 1 and the infrared receiving tube 2, and the infrared receiving tube 2 outputs an optical signal; the signal processing device 3 is used to receive the received optical signal output by the infrared receiving tube 2 converted into an electrical pulse signal; the main controller 4 is used to receive the electrical pulse signal, and calculate the signal to obtain a rotational speed signal; a display 5 is connected to the main controller 4 for displaying the rotational speed.

As shown in Figure 2, the main controller 4 selects AT89C52 single-chip microcomputer. The signal processing device 3 includes a first resistor R1, the cathode of the infrared emitting tube 1 is grounded, the anode of the first resistor R1 is connected in series with the collector of the triode Q1, and the base of the triode Q1 is connected in series with the sixth resistor R6 Afterwards, it is connected with the I/O serial port pin P10 of the single-chip microcomputer, and the collector of the triode Q1 is also connected in series with the second resistor (R2) and connected with the cathode of the infrared receiving tube 2, and the anode of the infrared receiving tube 2 Grounded, the cathode of the infrared receiving tube 2 is also connected to the input terminal of the inverter, and the inverting output terminal of the inverter is connected to the first interrupt terminal INT1 of the single-chip microcomputer. The first data terminal group P00-P07 and the second data terminal group P20-P27 of the single-chip microcomputer are all connected to the signal terminal group of the display 5 .

The display 5 adopts a liquid crystal display module of model JHD12864, and the liquid crystal display module adopts a drive chip of model HD44780. A sliding rheostat RW for adjusting the contrast of the liquid crystal display module is connected in series between the power terminal and the ground terminal of the liquid crystal display module. The sliding end of RW is connected with the contrast adjustment end of the liquid crystal display module.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (5)

1. based on ultrared tachometer of measuring, it is characterised in that include infrared ray speed measuring device, signal processing apparatus (3), master Controller (4) and display (5)；

Described infrared ray speed measuring device includes for launching ultrared infrared emission tube (1) and being used for the red of receiving infrared-ray Outside line receives pipe (2), described infrared receiver tube (2) output optical signal；

Described signal processing apparatus (3) is for being converted into electricity by the optical signal that the described infrared receiver tube (2) received exports Pulse signal；

Described master controller (4) is used for receiving electric impulse signal, and carries out counting to get tach signal by electric impulse signal；

Described display (5) is connected with described master controller (4), shows for rotating speed.

The most according to claim 1 based on ultrared tachometer of measuring, it is characterised in that described master controller (4) is AT89C52 single-chip microcomputer.

The most according to claim 2 based on ultrared tachometer of measuring, it is characterised in that also to include phase inverter, described Signal processing apparatus (3) includes the first resistance (R1) and audion (Q1), the minus earth of described infrared emission tube (1), sun Pole described first resistance (R1) colelctor electrode with audion (Q1) afterwards of connecting is connected, the base series the 6th of described audion (Q1) Resistor (R6) is connected with I/O serial port pin P10 of described single-chip microcomputer afterwards, and the colelctor electrode of described audion (Q1) also connects second Resistance (R2) negative electrode with described infrared receiver tube (2) afterwards is connected, and the plus earth of described infrared receiver tube (2) is described The negative electrode of infrared receiver tube (2) also input with described phase inverter is connected, and the reversed-phase output of described phase inverter is with described In the first of single-chip microcomputer, broken ends of fractured bone INT1 connects.

The most according to claim 2 based on ultrared tachometer of measuring, it is characterised in that the first number of described single-chip microcomputer According to end group (P00-P07), the second data terminal group (P20-P27), all signal end groups with described display (5) are connected.

The most according to claim 4 based on ultrared tachometer of measuring, it is characterised in that described display (5) uses Model is the LCD MODULE of JHD12864, and this LCD MODULE uses model to be the driving chip of HD44780, described liquid It is in series with the slide rheostat for regulating described display (5) contrast between power end and the ground terminal of brilliant display module RW, the sliding end of described slide rheostat is connected with the contrast adjustment end of described LCD MODULE.