CN205749553U - Based on ultrared tachometer of measuring - Google Patents

Abstract

The utility model relates to a rotational speed measuring instrument based on infrared rays, which comprises an infrared speed measuring device. 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 installed between the infrared emitting tube and the infrared receiving tube. , when the tooth disc rotates, due to the occlusion of the gear teeth, the infrared optical path between the infrared emitting tube and the infrared receiving tube is intermittent, and the signal processing circuit converts the changing optical signal into an electrical pulse signal, and a pulse signal means The chainring turns one 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 utility model is a rotational speed measuring instrument based on infrared radiation technology, has a simple structure, is convenient to install, has low requirements on the surrounding environment, has a wide dynamic measurement range, and has high measurement accuracy.

Description

Infrared-based tachometer

technical field

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

Background technique

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 developing velocity measurement technology. The instantaneous angular velocity of the rotating body is obtained through the laser Doppler effect. Expensive and limited in practical use.

Utility model content

The technical problem to be solved by the utility model is to provide a speed measuring instrument based on infrared rays, which has a simple structure, is easy to install, has low requirements on the environment, 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 utility model for solving 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 utility model: 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 light path between the infrared emitting tube and the infrared receiving tube is intermittent, and the signal The processing circuit converts the 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 utility model is a rotational speed measuring instrument based on infrared radiation technology, has a simple structure, is convenient to install, 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 utility model;

Fig. 2 is the schematic circuit diagram of the utility model.

detailed description

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

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 utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (5)

1. Based on the infrared speed measuring instrument, it is characterized in that comprising 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 an infrared receiving tube (2) for receiving infrared rays, and the infrared receiving tube (2) outputs an optical signal; The signal processing device (3) is used to convert the received optical signal output by the infrared receiving tube (2) into an electrical pulse signal; The main controller (4) is used to receive the electric pulse signal, and count the electric pulse signal to obtain the speed signal; The display (5) is connected with the main controller (4) for displaying the rotational speed. 2. the speed measuring instrument based on infrared ray according to claim 1, is characterized in that, described master controller (4) is AT89C52 single-chip microcomputer. 3. The speed measuring instrument based on infrared rays according to claim 2, characterized in that, it also includes an inverter, and the signal processing device (3) includes a first resistor (R1) and a triode (Q1), and the infrared ray The cathode of the emitting tube (1) 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 to the collector of the transistor (Q1) after being connected in series with the sixth resistor (R6). The I/O serial port pin P10 of the single-chip microcomputer is connected, and the collector of the triode (Q1) is also connected in series with the cathode of the infrared receiving tube (2) after the second resistor (R2), and the infrared receiving tube (2) ) of the anode is grounded, and 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. 4. The speed measuring instrument based on infrared rays according to claim 2, characterized in that, the first data terminal group (P00-P07) and the second data terminal group (P20-P27) of the single-chip microcomputer are all connected with the display (5) The signal end group connection. 5. the speed measuring instrument based on infrared ray according to claim 4, is characterized in that, described display (5) adopts the liquid crystal display module that model is JHD12864, and this liquid crystal display module adopts the drive chip that model is HD44780, and described liquid crystal A sliding rheostat RW for adjusting the contrast of the display (5) is connected in series between the power supply end and the ground wire end of the display module, and the sliding end of the sliding rheostat is connected to the contrast adjustment end of the liquid crystal display module.