RU2291798C2 - Method of and device for measuring deformation of vehicle body at road accident - Google Patents

Abstract

FIELD: transport engineering; measuring and checking facilities.

SUBSTANCE: invention relates to measuring of residual deformation of vehicle body after road accident. Proposed device contains contactless analog distance pickups and thickness measuring pickup. Distance pickups are arranged on bracket displaced in vertical and horizontal planes. Device contains also mount on end of which pickup of ultrasonic precision thickness gauge is found. Use of proposed device reduces labor input in measuring deformation of surfaces of complex form which makes it possible to carry out operative checking at place of road accident for estimating its causes, determining initial speeds of collision of vehicle with other vehicle or obstacle, and evaluating shock and strength properties of vehicle bodies.

EFFECT: reduced labor input in checking deformation of vehicle bodies after collision.

2 cl, 2 dwg

Description

The invention relates to measuring technique, in particular to measuring the permanent deformation of a car body during a traffic accident.

Known methods for determining plastic deformations and movements of car elements by linear measurements carried out before and after tests of impact strength properties. To determine the living space and assess the passive safety of the car, the distance between the projections of the baseline located in the undeformable zone and the control point located on the damaged surface on a horizontal plane is measured using a steel tape measure with an accuracy of ± 3 mm [1].

When editing car bodies, the geometry of the attachment points of the chassis nodes is checked, as well as the checkpoints of the floor of the body with a steel tape or ruler. Geometric parameters can also be checked using a self-centering sliding device. Angles in the vertical plane are checked using an angle goniometer with a level or a ruler with a protractor and a plumb line. Checking deviations from the horizontal plane is carried out using a level and leveling rod. The amount of skew is determined by comparing the damaged unit with the same intact on the same body or the undamaged side of the body of the same car [2].

Known stands that allow for the combined multi-point editing of an emergency body. For quick and accurate measurement of the external and internal dimensions of the body mounted on the stand, fully mobile measuring heads are used, containing mobile rulers with tips in their design [3].

Existing instrumentation and tools are structurally simple, but have limited capabilities, in particular the inability to control the geometric parameters of surfaces of complex shapes. In addition, the disadvantage of using existing tools and devices is the high complexity of the measurements and their insufficient accuracy.

A known method of controlling the geometry of bodies during editing, which consists in measuring using laser emitters mounted on a matrix and connected to sensors of the angle of rotation in two planes, the spatial coordinates of the points. The method consists in determining the size between two control points and comparing it with a reference size in three coordinates, which increases the productivity of the control process and its accuracy [4]. The existing method does not allow measuring the parameters of deformed surfaces of complex shape and has a narrow scope - it is used only to control the position of base points in space during the repair of emergency bodies.

Non-contact analog distance sensors are known having an electrical output signal, the magnitude of which is proportional to the distance to the measured object. The principle of operation of ultrasonic sensors is based on the emission of ultrasound pulses and measuring the time until the sound pulse, reflected from the measurement object, returns back to the sensor. The principle of operation of the laser optical sensor is based on the fact that the laser sends a beam through the lens, which is reflected from the object and is focused on the line of photodiodes, which converts the light signal into an electric one. Triangulation laser optical sensors are capable of measuring the distance to the object in the range from 10 mm to 1 m with an accuracy of 2 μm in 1 ms.

Known ultrasonic digital devices for measuring the thickness of protective coatings on any materials, metals and non-metals, as well as the total thickness or thickness of individual layers in one measurement cycle, having the function of automatic recognition of the type of material. Ultrasonic precision thickness gauges measure thickness by a non-destructive method with single-sided access in the range from 0.08 to 500 mm with an accuracy of 0.001 mm for both single-layer and multi-layer products.

The use of modern sensors to control the distance and thickness allows you to provide the necessary technical result of the claimed invention.

The technical result is to reduce the complexity of measuring the surface deformation of a complex shape, which makes it possible to carry out on-site inspection at the scene of an accident to assess its causes, determine the initial collision speed of cars or automobiles with an obstacle, and also allows to evaluate the impact strength properties of automobile bodies.

The technical result is achieved by the fact that the surface of a car body deformed as a result of an accident is measured in the form of a three-dimensional spatial dependence of the depth of deformation, the height and length of the deformed section, as well as the thickness of the deformed metal layer and is recorded for subsequent mathematical processing in electronic form in computer memory using an analog a digital converter and a device, which consists of a bracket moved by electric motors in the vertical and horizontal planes, on which there are three laser non-contact optical distance sensors, two of which control the position in the vertical and horizontal planes of the bracket itself and the third laser sensor, which measures the distance to the deformable part of the body, as well as a tripod, at the end of which there is an ultrasonic precision thickness gauge measuring the thickness of the deformed layers body metal and pressed to the surface of the body using a spring, while the control of electric motors is carried out using digital analog converter in accordance with the algorithm embedded in the computer.

The device is attached to the base with a hinge, which allows you to install a bracket with sensors for measuring roof or hood deformation from above, while laser distance sensors will monitor the position of the bracket in the horizontal plane relative to the longitudinal and transverse axes of the car, and the thickness sensor stand will occupy a vertical position.

The invention is illustrated by drawings. Figure 1 shows a device for measuring deformation of a car body, and figure 2 is a structural diagram of the connection of sensors.

The device for measuring the deformation of the body (Figure 1) consists of a bracket 3, which can be moved both in the vertical and horizontal planes. The bracket is moved in the vertical plane by an electric motor 2, on the shaft of which a gear wheel 1 is installed, which engages with a gear rack 9, which, in turn, is attached to the guide rack 10. The rollers 14 are guide elements when moving the bracket 3 along the rack 10. The movement of the bracket 3 in the horizontal plane is carried out together with the rack 10 relative to the frame 17 of the device. To move the rack relative to the frame, an electric motor 19 and a gear pair - gear 18 and rack 20 are used. The rack 20 is rigidly attached to the frame 17. The rollers 15 are guiding elements when moving the rack 10 along the frame 17. The frame 17 is attached to the base 13 using a hinge device consisting of a bracket 11 and an extension rod 12 with holes and allowing the frame to be installed in both vertical and horizontal positions.

Three laser non-contact optical distance sensors 4, 5 and 8 and a tripod 6 with a thickness gauge 7 sensor are installed on the bracket. Distance sensors 4 and 8 control the position of the bracket 3 and laser sensor 5 relative to the base surfaces located on the rack and frame of the device. When the device is running, the gauge of the thickness gauge 7 is constantly pressed against the surface of the car body using a spring 16.

The device operates as follows. In the memory of the computer are stored in electronic form the shape of the surfaces of bodies of various brands and models of vehicles recorded using the inventive device. To measure a portion of the body damaged as a result of an accident, the device is installed and fixed in the same position and at the same distance relative to the undeformed part of the car as during measurements before the accident. In accordance with the stored in the computer memory algorithm, the digital-to-analog converter of the DAC (Figure 2) supplies voltage and turns on the electric motor EDV, which moves the bracket with sensors in the vertical direction along the rack. The signal from the laser DRV distance sensor that controls the vertical position of the bracket is fed to one of the four channels of the analog-to-digital converter of the ADC, and then the computer processes it. When the bracket with sensors is moved vertically equal to the step of measuring the deformed surface, which is embedded in the device control algorithm, a signal is sent to the DAC, which turns off the EDV electric motor and supplies voltage to the DR laser sensor, which measures the distance to a point on the surface of the deformed body, as well as a sensor of the ultrasonic thickness gauge DT, which measures the thickness of the metal layers of the deformed body part. The signals from the DR and DT sensors are fed to the corresponding ADC channels, and then they are recorded in the computer memory. The mismatch of the beam of the distance sensor DR and the sensor axis of the thickness gauge DT is taken into account by a computer program.

By the thickness of the layers of the metal of the deformed section, a violation of the geometry of the hidden elements of the body is judged. If the body elements hidden by the shell, increasing its rigidity or strength, did not come into contact with the shell before the accident, and after a traffic accident, the gauge of the thickness gauge fixes a thickness greater than the thickness of the sheet metal of the shell, then the geometric shape of these elements is broken.

When the bracket with sensors is moved to the upper or lower end positions, a signal is supplied to the ADC channel from the DRV sensor, due to which the DAC turns on the EDG electric motor, which moves the bracket with sensors along the device frame in the horizontal direction by the size of the measurement step. In this case, the horizontal position of the bracket is controlled using a laser optical sensor DRG.

The laser optical sensor DR and the sensor of the ultrasonic thickness gauge DT measure the distance to the surface of the deformable section and the thickness of the deformed metal layers at each fixed position of the bracket in accordance with the device control algorithm recorded in the computer memory.

A comparison of the electronic forms of damaged surfaces and car body surfaces before an accident allows you to determine the depth of deformation and the dimensions of the deformable area.

Information sources

1. Ryabchinsky A.I. Passive car safety. - M.: Mechanical Engineering, 1983. - 145 p., Ill.

2. Katz A.M. Automobile bodies: Tech. service and repair. - 2nd ed., Revised. and add. - M.: Transport, 1980 .-- 272 p., Ill., Tab.

3. Equipment and tools for car service. Catalog. - M.: PFC "Scorpion", 1997.

4. Patent No. 2239505. The way to control the position of the points of the vehicle body during editing, 2004.12.20, application No. 2003112932/02, Russia.

Claims (2)

1. A device for measuring deformation of a car body, comprising non-contact analog distance sensors and a sensor measuring thickness, in which three laser non-contact optical distance sensors are located on a bracket moved by electric motors in the vertical and horizontal planes, two of which control the position in the vertical and horizontal planes the bracket and the third laser sensor, which measures the distance to the deformable part of the body, as well as a tripod, at the end of which a sensor precision ultrasonic thickness gauge, measuring the thickness of body layers of metal deformed and pressed against the surface of the body by a spring, wherein the motor is controlled by a digital to analog converter in accordance with an algorithm incorporated in a computer. 2. The device for measuring deformation of a car body according to claim 1, in which a hinge is attached to the base of the device, which allows you to install a bracket with sensors for measuring roof or hood deformation from above, while laser distance sensors will monitor the position of the bracket in a horizontal plane relative to the longitudinal and transverse axes of the car, and the tripod of the thickness gauge will occupy a vertical position.

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