WO2017026703A1

WO2017026703A1 - Device for self-detecting speed of vehicle using piezoelectric element and detection method therefor

Info

Publication number: WO2017026703A1
Application number: PCT/KR2016/008195
Authority: WO
Inventors: 이태형; 이재형
Original assignee: 주식회사 다음에너지; 주식회사 하이젠에너지; 이태형; 이재형
Priority date: 2015-08-11
Filing date: 2016-07-27
Publication date: 2017-02-16
Also published as: KR101598588B1

Abstract

The present invention relates to a device for self-detecting the speed of a vehicle, which self-detects the speed of a vehicle using a piezoelectric element, and analyzes and processes a detected signal so as to measure the speed of the vehicle, and a detection method therefor, the device comprising: a bracket which is fixedly mounted on the surface of a vehicle body so as to transmit vibration generated when a vehicle engine is driven; a piezoelectric element which is fixedly coupled to the bracket to convert the vibration transmitted through the bracket into a voltage signal so as to output the voltage signal; a low-pass frequency filter for removing a high frequency and noise from the voltage signal of the piezoelectric element and allowing a low frequency to pass therethrough; a gear shift ratio input unit for inputting a gear shift ratio for comparing the number of revolutions (RPM) of the wheel with the number of revolutions according to a gear shift of the vehicle; and a speed measuring CPU for converting the number of revolutions input by the gear shift ratio input unit and the low frequency input by the low-pass frequency filter into the speed of the vehicle according to the gear shift, so as to output the same. The present invention enables a device for self-detecting the speed of a vehicle to be installed at a desired position on a vehicle body without deforming or disassembling the vehicle, can lower the manufacturing cost of designing and manufacturing a circuit comprising a bracket, a piezoelectric element, a low-pass frequency filter, and a speed measuring CPU, can be easily applied to various devices using speed information of the vehicle, and improves the accuracy and reliability of a detection device.

Description

Specification

Name of the Invention: A vehicle's own speed sensing device using a piezoelectric element

Technical Field

[1] The present invention detects the vehicle's own speed with a piezoelectric element and analyzes and detects the detected signal.

It is about the device and method for measuring the speed of the vehicle by processing.

Background

[2] In general, GPS signals are detected by detecting and measuring the vehicle's own speed.

How to receive, how to detect the wheel, and how to detect changes in the vehicle engine.

[3] The method of receiving GPS signal is that the inertial navigation system detects the speed by calculating the change of time and the coordinates of the current position, and there is a problem that an error occurs because it is mainly used in the satellite navigation device, that is, the navigation. In addition, the speedometer that detects the speed and displays the speed is installed on all vehicles as a speed indicator.The speedometer is expressed in km / h in Korea, Japan, and Germany, and mile / h in the United States. In most cases, the speed display error is ± 5%, which is faster than the actual speed on the instrument panel.The speedometer also includes a built-in speed meter with a totalizer indicating the total distance traveled. A car with an alarm device measures 100 km per hour. Warnings are given by sound and light when they are exceeded. There are analogue methods for indicating the speed by means of the speedometer and digital method for displaying the numbers. The analogue method is to rotate the output shaft of the transmission from the worm gear. Uh oh it gigyejik out most often to induce the meter flexible shaft.

[4] Therefore, a speedometer mounted on a vehicle manufactured by a vehicle manufacturer cannot use the vehicle's own speed information for various additional devices, and the inertial navigation system that receives a GPS signal is accurate due to the error of the device itself. There was an unreliable problem.

Detailed description of the invention

Technical task

[5] The present invention has been made to solve the above problems, using piezoelectric element, bracket, low pass filter and transmission ratio input device to analyze and process the detection signal to measure the speed of the vehicle and use it with various devices related to the speed of the vehicle. Convenience

The purpose is to improve.

[6] The present invention also relates to vibration generated by the up and down movement of a piston inside a vehicle engine.

Alternative Paper (Article 126 of the Rules) Another purpose is to measure the speed of a vehicle by extracting the frequency domain from the engine speed (RPM) of the vehicle.

[7] The present invention also aims to install the vehicle anywhere in the vehicle body without any deformation or disassembly so that the vehicle's speed information is available to various devices by detecting and measuring the speed of the vehicle.

Task solution

[8] The present invention is a bracket which is fixed to the vehicle body surface of the vehicle to deliver the vibration generated when the vehicle engine is driven to achieve the above object; the vibration is fixed to the bracket and transmitted through the bracket as a voltage signal Piezoelectric element for converting and outputting; Low-pass filter for removing the high frequency and noise from the voltage signal of the piezoelectric element and passing the low frequency; According to the gear shift of the vehicle

A speed ratio input for inputting a wheel speed against a rotational speed (RPM), and a speed for converting the speed input from the speed ratio input and a low frequency input from a low pass filter into a speed of the vehicle according to the gear shift. For measurement

It is characterized by providing a vehicle's own speed sensing device using a piezoelectric element including a CPU.

In addition, in the present invention, the speed ratio input device may include a ratio of 3.214: 1 of each gear when the output of the engine generated from the crankshaft of the vehicle is converted into a driving force in the transmission.

In addition, the present invention, (a) inputting the speed ratio of the vehicle from the speed ratio input unit to the speed measuring CPU; (b) detecting vibration of the vehicle and converting the frequency into a frequency in a piezoelectric element coupled to the bracket fixed to the vehicle; (c) passing the frequency converted from the piezoelectric element after filtering the low frequency band from the low pass filter, and (d) the speed measuring CPU samples the signal input from the low pass filter to measure the number of revolutions. The present invention provides a method of detecting a vehicle's own speed using a piezoelectric element, which includes converting to a subsequent degree and outputting a speed value of the vehicle in comparison with the speed ratio input by the speed ratio input unit.

Effects of the Invention

[11] According to the present invention, the vehicle body can be installed at any place of the vehicle body without deforming or disassembling, and for measuring brackets, piezoelectric elements, low pass filters and speed measurement.

The manufacturing cost according to the design and manufacture of the circuit including the CPU is low, and it can be easily applied to various devices using the vehicle speed information, and the accuracy and reliability of the device for detecting the vehicle's own speed are improved.

Brief description of the drawings

1 is an embodiment according to the present invention, and shows the speed of a vehicle using a piezoelectric element.

This is a block diagram showing the sensing device.

2 is an apparatus for detecting a vehicle's own speed using a piezoelectric element according to the present invention. The configuration diagram shown.

3 is a flowchart illustrating a method of detecting a vehicle's own speed using a piezoelectric element according to the present invention.

[15] Explanation of codes

[16] 10: piezoelectric element

[17] 20: bracket

[18] 30: Low pass filter

[19] 40: CPU for speed measurement

[20] 50: Transmission ratio input unit

Mode for Carrying Out the Invention

[21] Hereinafter, a detailed description of the vehicle's own speed sensing device using a piezoelectric element according to the present invention will be given as follows.

1, the piezoelectric element 10 coupled to the bracket 20 fixedly mounted on one side of the vehicle is

The vibration signal of the vehicle is input to the low pass filter 30, and the low pass filter 30 inputs the baseband frequency to the speed measurement CPU 40 to sample the signal from the speed measurement CPU 40, and then the vehicle. Allows you to measure the engine speed (RPM).

The speed measurement CPU 40 converts the speed ratio input from the speed ratio input unit 50 of the vehicle so as to output the speed value.

In FIG. 2, the bracket 20 is fixedly mounted on the vehicle body surface to transmit vibrations generated when the vehicle engine is driven. The bracket 20 is a vibration of the vehicle, i.e., a piston operating inside the engine. It is preferable to be mounted where it can easily detect the rotational vibration of the tank shaft by the undressing movement, but it can be mounted anywhere that can detect the vibration generated after the vehicle starts up.

[24] The piezoelectric element 10 is fixedly coupled to the bra ¾ (20) to provide vibrations transmitted through the bracket.

It converts the voltage signal, that is, the frequency of a certain wavelength, and outputs it to the signal line 21. The piezoelectric element 10 represents a piezoelectric phenomenon and is called a piezoelectric element.

The piezoelectric element is mainly used for crystal, tourmaline or Rochelle salt. Recently, barium titanate, ammonium dihydrogen phosphate, ethylene diartarate, etc., which have excellent piezoelectricity by artificial crystals, are used. .

When pressure is applied in a certain direction, positive and negative charges appear on both sides of the plate in proportion to the external force.The piezoelectric force on one sheet is weak, but the amount is greatly increased when multiple sheets are inserted while inserting metal foil. There is a unique vibration, and when the elastic vibration and the electric vibration coincide, the vibration is combined with the piezoelectric force to generate a stronger vibration.

[25] The low pass filter 30 has a high frequency in the voltage signal of the piezoelectric element 10.

Active low pass by removing noise and passing low frequencies

The low pass filter 30 is a filter for passing the low part of the frequency. Therefore, the low pass filter 30 attenuates and cuts the frequency above a certain frequency except for a freely passable frequency pass. Furthermore, in the pulse code modulation (PCM) method, the analog signal is sampled at a constant sampling period to digitize the sampling again. In this case, it is a low-pass filter used to suppress the generation of noise by aliasing by blocking components with frequencies exceeding half of the sampling frequency included in the input analog signal.

[26] The speed ratio input device 50 is configured to determine the number of revolutions of the wheels according to the gear shift of the vehicle.

The gear ratio is the ratio of the engine speed to the speed of the propulsion or transmission spindle, that is, the ratio of the speed of the transmission input shaft to the speed of the output shaft, and the gear ratio according to the gear position. At low speeds with small rotational power but high driving force, the gear ratio is high, and at high speeds with high rotational power and small driving force, the gear ratio is small. Furthermore, the gear ratio is expressed as a value such as 3.214: 1 or 3.214 in simple terms. If the engine speed is 3,000rpm, the propeller shaft speed is 1,000rpm and the speed is decelerated by 1/3, and the speed of the wheel is decelerated once again by the differential gear and becomes less than 1,000rpm. The final reduction ratio.

[27] The speed measuring CPU 40 has a low pass and the rotation speed input from the speed ratio input device 50.

The low frequency frequency input from the filter 30 is converted into the speed of the vehicle according to the gear shift. The speed measurement CPU 40 has a rotational speed (RPM) so as to be consistent in converting the speed according to the gear shift of the vehicle. The speed ratio is input from a speed ratio input _{unit 50} capable of contrasting the rotational speed of the contrast wheel.

[28] The vehicle's own speed using the piezoelectric element of the present invention thus achieved

A method of detecting the vehicle's own speed from the sensing device will be described with reference to the flowchart of FIG. 3.

First, in Fig. 3, the speed measurement CPU 40 determines the speed ratio after the vehicle is started.

The speed ratio of the vehicle is input from the input device 50 (S11). At this time, when the vehicle does not move, the speed ratio value is not generated in the speed ratio input device 50, and the speed value of the vehicle is output from the speed measurement CPU 40. It doesn't work.

When the movement of the vehicle occurs, the vibration of the vehicle is detected by the piezoelectric element 10 coupled to the bracket 20 fixed to the vehicle (S12). The piezoelectric element 10 detects the vibration of the vehicle as a frequency signal. The frequency converted by the piezoelectric element 10 is outputted through the signal line 21 to the low pass filter 30, and then low pass.

The filter 30 filters the baseband among the input frequencies and then passes the signal (S14).

[30] The speed measuring CPU 40 passes the signal input from the low pass filter 30.

In step S15, the speed measurement CPU 40 samples the input signal with the value taken out at discrete time points. The speed measurement CPU 40 measures the rotational speed (RPM) from the sampled signal. Then, the speed measurement CPU 40 converts the measured rotation speed into the speed (S17), and compares the speed of the vehicle with the speed ratio input from the speed ratio input device 50. Output the speed value (SI 8).

[32] Therefore, the method for detecting the vehicle's own speed using the piezoelectric element of the present invention converts and analyzes the vibration frequency of the vehicle and the transmission ratio signal of the vehicle input from the speed ratio input unit in the piezoelectric element coupled to the bracket in the speed measuring CPU. And by outputting the vehicle's own speed by processing, there is an advantage to improve the utilization of various devices that use the speed of the vehicle.

While the invention has been shown and described in connection with specific embodiments thereof, it is to be understood that various modifications and variations are possible without departing from the spirit and scope of the invention as set forth in the claims. Anyone with normal knowledge in Easily know.

Claims

Claim

Claim 1 fixedly mounted to the vehicle body surface of the vehicle for transmitting a vibration generated when driving the vehicle engine;

A piezoelectric element fixedly coupled to the bracket and converting the vibration transmitted through the bracket into a voltage signal and outputting the voltage signal;

A low pass filter for removing the high frequency and noise from the voltage signal of the piezoelectric element and passing the low frequency;

A gear ratio ratio input for inputting a wheel speed to a wheel speed according to a gear shift of the vehicle, and

A speed detecting device for a vehicle using a piezoelectric element comprising a speed measuring CPU for converting the number of revolutions input from the speed ratio input unit and a low frequency frequency input from a low pass filter into a speed of the vehicle according to gear shift.

2. The vehicle speed sensing device according to claim 1, wherein the speed ratio input device includes a piezoelectric element including a ratio of 3.214: 1 of each gear when an output of the engine generated from the vehicle's tank shaft is converted into a driving force in the transmission. .

[Claim 3] (a) inputting a speed ratio of the vehicle from the speed ratio input unit to the speed measuring CPU;

(b) detecting vibration of the vehicle and converting the frequency into a frequency in a piezoelectric element coupled to the bracket fixed to the vehicle;

(c) passing the frequency converted by the piezoelectric element after filtering the low frequency band in the low pass filter, and

(d) the speed measuring CPU samples the signal input from the low pass filter, measures the rotation speed, converts the speed into a speed, and outputs the speed value of the vehicle in comparison with the speed ratio input from the speed ratio input device. A method of detecting a vehicle's own speed using a piezoelectric element.