CN102252691B - Measuring method of automobile tyre correction coefficient - Google Patents

Abstract

The invention discloses a measuring method of an automobile tyre correction coefficient. The method performs high-precision range finding mainly by forming an ultrasonic ranging mode by using an auxiliary target which is composed of two ultrasonic receivers with different mounting heights and fixed distances; performs accurate measurement of a driving stroke by the auxiliary target which is composed of the two ultrasonic receivers; performs continuous rotational angle measurement by forming a dip measuring mode by using a triaxial tilt sensor which does not require installation on a rotation shaft; performs accurate dip measurement by verticality correction, and realizes the accurate measurement of the tyre correction coefficient. The invention increases the measurement accuracy, and has simpler operation. As a measuring method of an automobile tyre correction coefficient, the invention is widely used in verification of taximeters.

Description

A kind of measuring method of automobile tyre correction coefficient

Technical field

The present invention relates to a kind of metering method, particularly relate to the method for the method of ultrasonic ranging and obliquity sensor angle measurement in conjunction with the measuring method that forms tire correction factor in the taximeter calibrating.

Background technology

Substantially all be to adopt simulated roadway at present, carry out the have the records of distance by the log calibrating of error of taximeter with the mode of cylinder, be specially: adopt the fee register that is formed by cylinder, control system, the frame error testing device of having the records of distance by the log, cylinder uses stainless steel, wear-resistant, the girth of cylinder generally is designed to 1 meter.During calibrating, the driving wheel carrier of taxi is on cylinder, rotating drive taxi wheel by the control system head roll synchronously rotates, reach the effect that simulating hires a car travels, the number of turns of measuring the cylinder rotation just can accurately obtain the mileage that cylinder rotates,, with this measured value of having the records of distance by the log that contrasts fee register, realize the have the records of distance by the log calibrating of error of fee register.

Use the mode of cylinder to examine and determine fee register, floor area is little, handled easily, but adopt curved surfaces (circumferential surface of cylinder) to replace the road surface, plane of actual travel during due to calibrating, the deformation of automotive wheel on these two kinds of geometric configuration objects is different, cause very large impact, namely had the tire correction factor.The tire correction factor refers to that wheel rotates a corresponding distance travelled of fixing turn fee register in the plane, rotates the ratio of the corresponding distance travelled of same number of turns fee register with wheel on curved surfaces.By great many of experiments, the tire correction factor can reach more than 2%, if do not revise have a strong impact on the confidence level that fee register is examined and determine, so the accuracy of tire correction factor is the key factor that the fee register calibrating is controlled.

There is no at present special-purpose tire correction factor measurement mechanism, generally adopt general survey instrument such as steel tape to measure, labour intensity is large, and personal error is large, and accuracy is not high.

The physical quantity that the tire correction factor is measured has two: stroke (distance) and corner.

Ultrasonic ranging is a kind of non-contact distance-measurement mode commonly used, and its measuring principle is that to utilize the aerial velocity of propagation C of ultrasound wave be known, measures ultrasound wave is propagated in testing distance L time T, presses physical equation L=C * T and calculates distance.As the ultrasonic ranging accuracy, key is the accuracy of the time T accuracy of measuring and the velocity of sound C that obtains., for velocity of sound C, be wherein generally to use by physical constant, but in fact, the velocity of sound is relevant with the characteristic of the medium of propagating, such as the composition of medium, temperature of medium etc., while propagating in air, relevant with regard to the temperature with air, air pressure etc.At present the ultrasonic range finder research field all at the characterisitic parameter (as temperature) of studying Measurement accuracy medium how in order to velocity of sound C is revised, improve the accuracy of ultrasonic ranging.But this correcting mode, one is subjected to the accuracy limitations of survey parameter, and two limited the mathematical model that the velocity of sound affects by this characterisitic parameter, and three are subjected to the restriction of velocity of sound Study on influencing factors.

Simultaneously, ultrasonic ranging is to measure between fixed two measurement points, and the stroke measurment point of tire correction factor needs just to determine two measurement points after running car, if will realize measuring automatically the problem that needs to consider to measure abbe ' s principle.

Obliquity sensor can be at Measurement accuracy inclination angle under static state, but the outer corner measurement of tire correction factor is to carry out under dynamically, needs to solve the problem of successive dynamic measuring.Simultaneously, the actual state during due to measurement can not guarantee vertical measurement face, needs to adopt three axial rake sensors to solve the problem that affects of verticality.

Summary of the invention

In order to solve above-mentioned technical matters, the objective of the invention is to solve artificialization of automobile tyre correction coefficient measuring process, adopt ultrasound wave comparative measurement method measuring distance, and stroke is measured in the correction that realizes the measurement abbe ' s principle, the impact of adopting simultaneously the three dynamic rotational angles of axial rake sensor measurement and solving verticality, provide a kind of automobile tyre correction coefficient automatically, Accurate measurement.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of measuring method of automobile tyre correction coefficient, the method comprises the steps:

A. the emission element of supersonic range finder is positioned on the automobile head position, auxiliary target is placed on approximately 15m place, the place ahead, two setting height(from bottom)s differences are arranged but the fixing ultrasonic receiver of distance on auxiliary target, be called the target receiver and compare receiver, after auxiliary target and emission element are aimed at, measure distance L 1 and the ultrasonic velocity C of emission element to auxiliary target target receiver;

B. with the angle measurement parts of three axial rake sensors be positioned on the automotive wheel center near, and make the X-direction level, obtain zero starting point inclination angle;

C. start the taxi low speed driving, the angle measurement parts detect the rotation number of turns n of wheel, travel after 5 circles, stop and stop automobile, and distance member is measured to distance L 2, the r of auxiliary target target receiver and comparison receiver, and the angle measurement parts are measured the terminal inclination alpha;

D. remove distance measuring equipment, another angle measurement parts are installed near the rotating shaft of fee register use error calibrating installation cylinder, taxi drives wheel carrier on cylinder, and makes two angle measurement parts X-direction levels, obtains zero starting point inclination angle;

E. start the taxi low speed driving, detect rotation number of turns n1, the n2 of wheel and cylinder, travel after 5 circles, stop and stop automobile, measure terminal angle of inclination beta and γ;

F. calculate tire correction factor S according to the above-mentioned data of surveying, formula is Wherein

α _r=α+n * 360 °, β _r=β+n1 * 360 °, γ _r=γ+n2 * 360 °.

Be further used as preferred embodiment, in the step A, the ultrasonic receiver that two setting height(from bottom)s are different and distance is fixing is arranged on described auxiliary target, the poor 2d of setting height(from bottom) is that 20mm to 40mm and target receiver position are low, two receivers are 0.5m to 1.0m at a distance of Lr, and these data need accurate calibration.

Be further used as preferred embodiment, in the step A, described aligning is that a parallel laser indication device is installed in the middle of the setting height(from bottom) of two receivers, with the height that this laser indication device is adjusted auxiliary target, the transmitter of distance measuring equipment is on laser designation light and realizes aiming at, what realize that two receivers depart from index line (being slotted line) is 10mm to 20mm apart from d.

Be further used as preferred embodiment, in the step A, the mode of described measuring distance L1 is to measure ultrasound wave be transmitted to the time T 11 of target receiver and to the time T 12 that compares receiver, press from transmitter

Calculate.

Be further used as preferred embodiment, in the step B, described angle measurement parts be positioned on the automotive wheel center near, and need not be arranged on the rotation axis of wheel.

Be further used as preferred embodiment, in described B, D step, described angle measurement parts X-axis need be carried out horizontal adjustment, and measures the output valve Y (V0) of angle measurement parts Y-axis under this state.

Be further used as preferred embodiment, in the step C, described distance member measure to receiver relatively apart from r, press Calculate.

Be further used as preferred embodiment, in described C, E step, described measurement terminal inclination angle is output valve X (Vout), Y (Vout), the Z (Vout) that measures the angle measurement component triaxial under this state, when the Z axis sensor is in ± 45 ° the time, presses

Calculate inclination alpha, when the X-axis sensor is in ± 45 ° the time, presses

Calculate inclination alpha, wherein

Be further used as preferred embodiment, in the step D, another angle measurement parts be installed near the rotating shaft of described fee register use error calibrating installation cylinder.

The present invention adopts the self-correcting comparative measurement method to realize the correction of acoustic velocity value, and this measuring method is comparative method for measuring, does not have velocity of sound C in measurement, does not namely need acoustic velocity value, does not more have the correction to the velocity of sound.Only need to guarantee to measure under same environment simultaneously, this is guaranteed by measurement procedure.

The invention has the beneficial effects as follows: the present invention, by the mode of two ultrasonic receivers, has avoided the problem of acoustic velocity value, need not carry out the measurement of acoustic velocity value correction, has reduced the physical quantity of measuring; Use distance between ultrasound wave target receiver and comparison receiver (relatively distance) as the constant of measuring, and its accuracy is higher as the constant of measurement than using acoustic velocity value, has improved the accuracy of measurement; The mode that adopts ultrasonic transmitter to separate with receiver, than in the echometric measurement mode, having improved reliability, and increased the measurement range more than a times under square one; Adopt ultrasound wave target receiver and the ultrasonic signal that compares the same transmitter of receiver reception, it is convenient, accurate that signal is differentiated; Employing target receiver and the dual receiver mode that compares receiver, the correction of measuring Abbe error, can measure actual running car stroke, in the situation that do not need starting point and the terminal of stroke are carried out manually identifying and realizing automatic stroke measurment; Use 3-axis acceleration sensor under the slow-speed of revolution, the installation site of sensor need not be contained on axis of wheel rotation, realized non-coaxial mounting means measurement rotational angle, metering system is simple and reliable, has solved the operability difficult problem of the coaxial installing angle sensor of automotive wheel; Adopt the verticality correcting mode, made the installation site of sensor there is no the requirement of verticality, only needed to adjust horizontal level, processing ease.

Description of drawings

The invention will be further described below in conjunction with drawings and Examples.

Fig. 1 is measurement scheme schematic diagram of the present invention;

Fig. 2 is relative method ultrasonic ranging schematic diagram;

Fig. 3 is relative method ultrasonic measurement geometric model figure;

Fig. 4 measures the Abbe error schematic diagram;

Fig. 5 is the triangulation model of measuring stroke;

Fig. 6 is angle measurement component installation state schematic diagram.

Embodiment

A kind of measuring method of automobile tyre correction coefficient, the method comprises the steps:

A. the ultrasonic ranging emission element is positioned on the automobile head position, auxiliary target is placed on approximately 15m place, the place ahead, the ultrasonic receiver that two setting height(from bottom)s are different and distance is fixing (be called the target receiver and compare receiver) is arranged on auxiliary target, the poor 2d of setting height(from bottom) is that 20mm and target receiver position are low, and two receivers are 0.5m (these data need accurate calibration) at a distance of Lr.One parallel laser indication device is installed in the middle of the setting height(from bottom) of two receivers, with the height that this laser indication device is adjusted auxiliary target, the transmitter of distance measuring equipment is on laser designation light and realizes aligning.The range finding emission element sends ultrasonic signal to the ultrasonic ranging auxiliary target, and starts time set simultaneously; After two ultrasonic sensors of ultrasonic ranging auxiliary target receive ultrasonic signal, send infrared signal to the range finding emission element respectively; After the ultrasonic ranging parts receive respectively two wireless signals that send of ultrasonic ranging auxiliary target, the triggering timing device, measure ultrasound wave from transmitter be transmitted to after the time T 11 of target receiver and ultrasound wave is transmitted to the comparison receiver from transmitter time T 12 by

Calculate the distance L 1 of emission element to auxiliary target target receiver, press

Calculate real-time ultrasound wave sound speed C.

B. with the angle measurement parts of three axial rake sensors be positioned on the automotive wheel center near, adjust the installation site of three axial rake sensors, adopt the voltage measurement device to monitor that the inclination angle that makes X-axis is zero, obtain zero first primary dip, and measure simultaneously and record the output voltage values Y (V0) of Y-axis, be used for the automatic correction of verticality.

C. start taxi low speed driving (speed is lower than 5km/h), in the process of moving, the X, the Z axis output signal that adopt counter, four to segment and debate to circuit measuring three axial rake sensors are carried out the measurement of vehicle wheel rotation number of turns n; Travel after 5 circles, stop and stop automobile, measure ultrasound wave by the mode of above-mentioned A step and be transmitted to the time T 21 of target receiver and, to the time T 22 that compares receiver, press from transmitter

With

Calculate emission element to the distance L 2 of auxiliary target target receiver and to receiver relatively apart from r.After adopting the voltage measurement device to measure three axle output voltage values X (Vout), the Y (Vout) of current location three axial rake sensors, Z (Vout), mode by coordinate system transformation, the X-axis sensor of using is projected to angle after vertical guide as inclination alpha, and computing formula is as follows;

$\cos \left(\mathrm{\α}\right)=\frac{Y\left(V0\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}\×\frac{Y\left(V_{\mathrm{out}}\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}+\frac{Z\left(V0\right)-Z\left(\mathrm{offset}\right)}{Z\left(S\right)}\×\frac{Z\left(V_{\mathrm{out}}\right)-Z\left(\mathrm{offset}\right)}{Z\left(S\right)}$ Formula (1)

Or:

$\cos \left(\mathrm{\α}\right)=\frac{Y\left(V0\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}\×\frac{Y\left(V_{\mathrm{out}}\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}+$

$\frac{Z\left(V0\right)-Z\left(\mathrm{offset}\right)}{Z\left(S\right)}\×\sqrt{1-{\left(\frac{X\left(V_{\mathrm{out}}\right)-X\left(\mathrm{offset}\right)}{X\left(S\right)}\right)}^2-{\left(\frac{Y\left(V_{\mathrm{out}}\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}\right)}^2}$

Formula (2)

Current location Z axis sensor is in ± and 45 ° the time, adopt formula (1) to calculate inclination angle, current location X-axis sensor is in ± and 45 ° the time, adopt formula (2) to calculate inclination angle;

In above-mentioned formula:

X (offset), Y (offset), Z (offset): the zero output voltage value of three axial rake sensors X axles, Y-axis, Z axis is the eigenwert of sensor, demarcates in advance;

X (S), Y (S), Z (S): the output sensitivity of three axial rake sensors X axles, Y-axis, Z axis under plumbness is the eigenwert of sensor, demarcates in advance;

D. remove distance measuring equipment, another angle measurement parts are installed near the rotating shaft of fee register use error calibrating installation cylinder, taxi drives wheel carrier on cylinder, adjust the installation site of two angle measurement parts, adopt the voltage measurement device to monitor that the inclination angle that makes X-axis is zero, obtain zero first primary dip, and measure simultaneously and record Y-axis output valve Y (V0), be used for the automatic correction of verticality.

E. start the taxi low speed driving, detect rotation number of turns n1, the n2 of wheel and cylinder by the mode of above-mentioned C step, travel after 5 circles, stop and stop automobile, by the mode of above-mentioned C step, measure terminal angle of inclination beta and γ;

F, be calculated as follows tire correction factor S:

In formula: 1: the have the records of distance by the log cylinder girth of error testing device of fee register, need to demarcate in advance, be generally 1m.

$L=\sqrt{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1}^2+\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1\&CenterDot;\mathrm{Lr}-({{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}^2+r^2)\frac{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1}{\mathrm{Lr}}+{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}2}^2}$

α _r＝α+n×360°

β _r＝β+n1×360°

γ _r＝γ+n2×360°

By reference to the accompanying drawings key principle is elaborated:

Measurement scheme of the present invention is as shown in Figure 1: adopt three axial rake sensors (1), based on verticality, automatically revise (2) and segment and debate Measurement accuracy (4) from continuous rotational angle to circuit (3) that realize; Adopt the auxiliary target (6) of ultrasonic wavelength-division emitter (5) and dual receiver, method is measured apart from (7) and triangulation model (8) and is realized stroke measurment (9) accurately based on the comparison, thereby realizes the Measurement accuracy (10) of tire correction factor in the taximeter calibrating.

Relative method ultrasonic ranging principle of the present invention is as follows:

Adjust the distance L1 and L2 (when establishing L2＞L1) and adopting ultrasound wave mode measuring distance:

L1=C1 * T1 formula (3)

L2=C2 * T2 formula (4)

In formula, C is the velocity of sound, and T1, T2 are the time that the spontaneous emitter of ultrasound wave is transmitted to receiver;

If guarantee to measure under same environment simultaneously, C1=C2, establish L=L1, L2=L+Lr, and the conversion by to formula (3) and (4) obtains:

This measuring method is comparative method for measuring, does not have velocity of sound C in measurement, does not namely need acoustic velocity value, does not more have the correction to the velocity of sound.Only need to guarantee to measure under same environment simultaneously, this is solved by measurement procedure.This measuring method is many measured value Lr, this is the difference Lr between measured target and comparison object distance, for distance difference Lr, adopt the mode of two ultrasonic receivers to be solved, two receivers are arranged on an object that is called auxiliary target, the spacing Lr of two receivers (relatively distance) is known through measuring (demarcation), thereby realizes comparing and measuring.By the technical capability of present distance calibration, the demarcation accuracy of reference distance L r can reach more than 0.02%.

During specific implementation, as shown in Figure 2, ultrasonic transmitter is in A point position, and ultrasound wave target receiver is in B point position, and ultrasound wave comparison receiver is in Br point position, and AB is testing distance L, and BBr is comparison distance L r.A in theory, B, 3 of Br in line the time accuracy of measurement the highest, if but like this front receiver B will block rear receiver Br, make receiver Br can not directly receive ultrasound wave, therefore be designed to 3 not measure geometry models of conllinear, as shown in Figure 3, A and B, the central point of Br forms the dimensional measurement model of slotted line in line, B, Br departs from slotted line and is recommended as 10mm apart from d, this slotted line is by being arranged on sighting device on auxiliary target (in the implementation case, use the high brightness laser pen as sighting device) position, boresight is exactly this slotted line, the range finding computing formula of bringing thus is:

$L=\sqrt{{(\mathrm{Lr}\&CenterDot;\frac{T_1}{T_2-T_1})}^2-{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}$

Stroke measurment Abbe error correction principle of the present invention is as follows:

Range observation in the tire correction factor, it is the distance that measured automobiles is travelled, metering system is to adopt an object, distance L 1 before automobile starting between measured automobiles and object, the distance L 2 between measured automobiles and object again after automobile stops, obtaining the distance L of running car according to the difference of these two distances, as shown in Figure 4, be difficult in practice control this three in line, bring due to the caused Abbe error of triangle relation, i.e. L ≠ L1-L2.

, due to the measurement scheme that adopts dual receiver, can revise Abbe error exactly:

As shown in Figure 5, measure the distance L 1 of B between an A and impact point at the running car before measurement, the reference distance L r by known, can obtain acoustic velocity value C accurately; Automobile to overtake,, even without the direction according to AB, stops at actual terminal A ', and can measure distance L 2 between terminal A ' and impact point B this moment, and terminal A ' and comparison receiver Br apart from r.Because the direction of running car does not form an angle ∠ Br in the direction of AB, so the distance of running car can not subtract L2 with L1, i.e. L ≠ L1-L2.But, according to cosine formula, can obtain very accurately distance L:

Diabolo △ AA ' Br:

$\cos \mathrm{Br}=\frac{{(\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1+\mathrm{Lr})}^2+r^2-{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}}^2}{2(\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1+\mathrm{Lr})\&CenterDot;r}$

Diabolo △ BA ' Br

$\cos \mathrm{Br}=\frac{{\mathrm{<figure-callout\; id="2"\; label="Lr"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">Lr</figure-callout>}}^2+r^2-{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}2}^2}{2\mathrm{Lr}\&CenterDot;r}$

, through mathematical operation, can obtain:

$L=\sqrt{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1}^2+\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1\mathrm{Lr}-({{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}^2+r^2)\frac{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}1}{\mathrm{Lr}}+{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">L</figure-callout>}2}^2}$

In formula:

$r=\sqrt{{(C\&times;T_{22})}^2-{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HSA00000474280000011.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}$

The principle of three axial rake sensor measurement rotational angles of the present invention is as follows:

The measurement model of obliquity sensor is:

$\mathrm{\&alpha;}=\arcsin \frac{V_{\mathrm{out}}-\mathrm{offset}}{S}$

In formula: α: the angle of inclination of relative level face, (°);

Vout: the output voltage values of obliquity sensor, (V);

Offset: the output voltage values of obliquity sensor when zero inclination angle, (V);

S: the output sensitivity of obliquity sensor, (V/g).

Because obliquity sensor only has higher accuracy of measurement in-45 °～+ 45 ° inclination angle scopes, therefore use the Z axis of diaxon obliquity sensor realize-90 °～-45 ° ,+Measurement accuracy at 45 °～+ 90 ° of inclination angles, and realize simultaneously 0 °～360 ° four-quadrant measurements, because automobile is to travel in the plane, it is constant that X, Z axis obliquity sensor are projected to the inclination angle relation of vertical guide, therefore adopts X, Z axis sensor to realize that the four-quadrant measurement of angle is accurately.

Because obliquity sensor need be arranged on wheel, but installation site is irregular, can not guarantee that obliquity sensor can be perpendicular to rotational plane, although can adopt adjusting mechanism realizes, but because three-dimensional adjuster complex structure is huge, therefore only adopt one dimension only to adjust horizontal level, but the same problem that exists perpendicular to rotational plane, as shown in Figure 6.Inclination has occurred in former two axle sensors (Ox and Oz) that should measure wheel vertical guide OABC rotational angle, because wheel rotates with axletree, axletree is parallel ground, wheel is made circular-rotation on vertical guide, but sensor is that (hyperboloid Oxx ' and hyperboloid Ozz ') rotates on dip plane, sensor inclination angle with respect to the horizontal plane is not angle of circumference, rotational angle that can not the Measurement accuracy wheel.Adopt three axial rake sensors,, as long as guarantee to obtain the incident angle of another diaxon when the X-axis horizontal level, can carry out verticality according to the principle of coordinate transform and automatically revise.During installation, the X-axis obliquity sensor points to the wheel working direction, and the Y-axis obliquity sensor points to axial direction, the top of Z axis obliquity sensor directed in orthogonal direction.

Under rotary state, thereby producing radial acceleration, centrifugal acceleration affects the measurement accuracy of the free acceleration of obliquity sensor, but because the applied rotary state measurement of the present invention only needs X, Z axis output voltage curve, segment and debate the number of turns of to circuit measuring, rotating by four, do not need under rotary state inclination angle value accurately, as long as centrifugal acceleration is not destroyed the shape of output voltage curve.Owing to using low speed (lower than 5km/h) is lower, centrifugal acceleration is not more than 0.2g, therefore adopts to take back stagnant comparator circuit and realize that four segmentations eliminate the impact that centrifugal acceleration is measured rotating the number of turns fully.

More than that better enforcement of the present invention is illustrated, but the invention is not limited to described embodiment, those of ordinary skill in the art also can make all equivalent variations or replacement under the prerequisite without prejudice to spirit of the present invention, the modification that these are equal to or replacement all are included in the application's claim limited range.

Claims (8)

1. the measuring method of an automobile tyre correction coefficient, it is characterized in that: the method comprises the steps:

A. the emission element of supersonic range finder is positioned on the automobile head position, auxiliary target is placed on approximately 15m place, the place ahead, two setting height(from bottom)s differences are arranged but the fixing ultrasonic receiver of distance on auxiliary target, be called the target receiver and compare receiver, after auxiliary target and emission element are aimed at, measure distance L 1 and the ultrasonic velocity C of emission element to auxiliary target target receiver;

B. with the angle measurement parts of three axial rake sensors be positioned on the automotive wheel center near, and make the X-direction level, obtain zero starting point inclination angle;

C. start the taxi low speed driving, the angle measurement parts detect the rotation number of turns n of wheel, travel after 5 circles, stop and stop automobile, and distance measuring equipment is measured to distance L 2, the r of auxiliary target target receiver and comparison receiver, and the angle measurement parts are measured the terminal inclination alpha;

D. remove distance measuring equipment, near fee register is had the records of distance by the log the rotating shaft of error testing device cylinder, another angle measurement parts are installed, taxi drives wheel carrier on cylinder, and makes two angle measurement parts X-direction levels, obtains zero starting point inclination angle;

E. start the taxi low speed driving, detect rotation number of turns n1, the n2 of wheel and cylinder, travel after 5 circles, stop and stop automobile, measure terminal angle of inclination beta and γ;

F. calculated tire correction factor S according to the survey data, formula is

Wherein $L=\sqrt{L{1}^2+L1\&CenterDot;\mathrm{Lr}-(L{2}^2+r^2)\frac{L1}{\mathrm{Lr}}+L{2}^2},$ $r=\sqrt{{(C\&times;T_{22})}^2-d^2},$ α _r=α+n * 360 °, β _r=β+n1 * 360 °, γ _r=γ+n2 * 360 °; In formula, l is the have the records of distance by the log cylinder girth of error testing device of fee register, and Lr is target receiver and the distance of receiver relatively, T ₂₂Be transmitted to the time of comparison receiver from transmitter for ultrasound wave, d is the target receiver and compares 1/2nd of receiver difference in height.

2. the measuring method of a kind of automobile tyre correction coefficient according to claim 1, it is characterized in that: in the step A, the ultrasonic receiver that two setting height(from bottom)s are different and distance is fixing is arranged on described auxiliary target, the poor 2d of setting height(from bottom) is that 20mm to 40mm and target receiver position are low, two receivers are 0.5m to 1.0m at a distance of Lr, and these data need accurate calibration.

3. the measuring method of a kind of automobile tyre correction coefficient according to claim 1, it is characterized in that: in the step A, described aligning is that a parallel laser indication device is installed in the middle of the setting height(from bottom) of two receivers, with the height that this laser indication device is adjusted auxiliary target, the transmitter of distance measuring equipment is on laser designation light and realizes aiming at, what realize that two receivers depart from laser designation light is 10mm to 20mm apart from d.

4. the measuring method of a kind of automobile tyre correction coefficient according to claim 1, it is characterized in that: in the step A, the mode of measuring distance L1 is to measure ultrasound wave be transmitted to the time T 11 of target receiver and to the time T 12 that compares receiver, press from transmitter $L1=\sqrt{{(\mathrm{Lr}\&CenterDot;\frac{T_{11}}{T_{12}-T_{11}})}^2-d^2}$ Calculate.

5. the measuring method of a kind of automobile tyre correction coefficient according to claim 1 is characterized in that: in the step B, described angle measurement parts be positioned on the automotive wheel center near, and need not be arranged on the rotation axis of wheel.

6. the measuring method of a kind of automobile tyre correction coefficient according to claim 1, it is characterized in that: in described B, D step, described angle measurement parts X-axis need be carried out horizontal adjustment, and measures the output valve Y (V0) of angle measurement parts Y-axis under this state.

7. the measuring method of a kind of automobile tyre correction coefficient according to claim 1 is characterized in that: in the step C, described distance measuring equipment measure to receiver relatively apart from r, press $r=\sqrt{{(C\&times;T_{22})}^2-d^2}$ Calculate.

8. the measuring method of a kind of automobile tyre correction coefficient according to claim 1, it is characterized in that: in described C, E step, described measurement terminal inclination angle is output valve X (Vout), Y (Vout), the Z (Vout) that measures the angle measurement component triaxial under this state, when the Z axis sensor is in ± 45 ° the time, presses

$\cos \mathrm{\&alpha;}=\frac{Y\left(V0\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}\&times;\frac{Y\left(V_{\mathrm{out}}\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}+\frac{Z\left(V0\right)-Z\left(\mathrm{offset}\right)}{Z\left(S\right)}\&times;\frac{Z\left(V_{\mathrm{out}}\right)-Z\left(\mathrm{offset}\right)}{Z\left(S\right)}$ Calculate inclination alpha, when the X-axis sensor is in ± 45 ° the time, presses

$\cos \mathrm{\&alpha;}=\frac{Y\left(V0\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}\&times;\frac{Y\left(V_{\mathrm{out}}\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}+$

$\frac{Z\left(V0\right)-Z\left(\mathrm{offset}\right)}{Z\left(S\right)}\&times;\sqrt{1-{\left(\frac{X\left(V_{\mathrm{out}}\right)-X\left(\mathrm{offset}\right)}{X\left(S\right)}\right)}^2-{\left(\frac{Y\left(V_{\mathrm{out}}\right)-Y\left(\mathrm{offset}\right)}{Y\left(S\right)}\right)}^2}$ Calculate inclination alpha, wherein

And X (offset) is the zero output voltage value of three axial rake sensors X axles, and Y (offset) is the zero output voltage value of three axial rake sensor Y-axis, and Z (offset) is the zero output voltage value of Z axis; X (S) is the output sensitivity of three axial rake sensors X axles under plumbness, and Y (S) is the output sensitivity of three axial rake sensor Y-axis under plumbness, and Z (S) is the output sensitivity of three axial rake sensor Z axis under plumbness; Y (V0) is the output voltage values of angle measurement parts Y-axis when the X-direction level, and Z (V0) is the output voltage values of angle measurement parts Z axis when the X-direction level.

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