JP2006090795A - Performance evaluation method and system for chassis dynamometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein a chassis dynamometer, provided with an electrical inertia compensation function is incapable of high precision of performance evaluation of the load condition at testing. <P>SOLUTION: The load condition of the dynamometer is evaluated as follows: the speed detection signal Vm and torque signal FLC measured by the speed detector and the torque detector are directly introduced to the separately installed evaluation device; the parameters of the previously set running resistance and the mechanical loss signal FML are inputted; any one of driving force, work rate and amount of work are calculated in the evaluation operation part, by using these parameters of running resistance, mechanical loss signal FML and the speed detection signal Vm, based on the calculated value, the load conditions of the dynamometer can be evaluated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and an apparatus for evaluating the performance of a chassis dynamometer.

  In the chassis dynamometer system, the drive wheel of a completed vehicle is placed on a roller, the vehicle is controlled by a predetermined operation command, and the vehicle performance test is performed using a dynamometer connected to the rotating shaft of the roller as a power absorber. And durability tests are possible indoors. The running resistance of the vehicle at that time is the flat road steady running consisting of tire rolling resistance, mechanical loss and air resistance plus inertia resistance and climbing slope resistance. In the dynamometer, torque by coefficient conversion of running resistance component Controlled by signal. Of this running resistance, a flywheel whose inertial resistance is set to an inertia equivalent to that of the actual vehicle may be used. However, the flywheel is adjusted as the absorption torque of the dynamometer due to the increased installation space. Equivalent inertia compensation is adopted.

By the way, as a method for adding an equivalent inertial mass, there are a flywheel method, an electric inertia method, and a combination of a flywheel method and an electric inertia method. Hereinafter, a chassis dynamometer using the electric inertia method will be described as an example. .
Non-Patent Documents 1 to 4 are known as documents relating to the performance evaluation of the chassis dynamometer, and whether or not the equivalent inertia compensation for simulating the load state of the chassis dynamometer is appropriately adjusted. As an evaluation method of equivalent inertia compensation for verification, Patent Document 1 is publicly known.
Non-Patent Documents 1 to 4 and Patent Document 1 describe that a correlation and a difference between a target driving force and an actual driving force in a vehicle are statistically evaluated. The European standard ECE15 exists, and the response speed and accuracy of equivalent inertia compensation are calculated by calculating the total inertia I = I ₀ + Fi / γ (where I ₀ is fixed inertia, Fi is electrical inertia, and γ is acceleration). Is evaluated.
1996 Specific Research Results Collection “Research on Performance Requirements of Chassis Dynamometer for Emissions and Fuel Consumption Evaluation of 4WD Vehicles” Noda et al., Ministry of Transport, Traffic Safety and Pollution Research Institute 1997 Specific Research Results Collection “Test Survey on Performance Requirements of Chassis Dynamometer for Emissions and Fuel Consumption Evaluation of 4WD Vehicles” Noda et al., Ministry of Transport, Traffic Safety and Pollution Research Institute 1998 Specific Research Results Collection “Test Survey on Performance Requirements of Chassis Dynamometers for Emission and Fuel Consumption Evaluation of 15.4WD Vehicles” Noda et al., Ministry of Transport, Traffic Safety and Environmental Research Institute 1998 Traffic Safety and Pollution Research Institute Research Presentation Lecture Summary “Research on Chassis Dynamometer for 4WD Vehicles” Noda et al., Ministry of Transport, Traffic Safety and Pollution Research Institute JP 2004-219185 A

In order to correctly evaluate the load applied to the vehicle from the chassis dynamometer, it is necessary to verify the accuracy of running resistance and electric inertia during mode operation. In order to perform verification with the vehicle mounted on the chassis dynamometer, the running resistance, control accuracy of electric inertia, response speed, etc. in the same state as the vehicle fuel consumption and exhaust gas inspection state are investigated and performance evaluation is performed. Therefore, there is a need for an evaluation method and an evaluation apparatus for them. Non-Patent Documents 1 to 4 described above describe the evaluation method, but do not describe a technique for realizing it. Patent Document 1 describes verification means for verifying whether or not the equivalent inertia compensation for simulating the load state of the chassis dynamometer is appropriately adjusted. Because it is calculated by the system, a phase delay occurs for each chassis dynamometer due to the influence of filter elements inserted to stabilize the signal, and the differential calculation method provided for acceleration calculation is not unified. Although it was possible to evaluate the chassis dynamometer alone, absolute evaluation was not possible.
Also, in ECE15, since the division of acceleration appears in the calculation, the inertial calculation value is difficult to stabilize. Especially in the portion where the acceleration crosses zero, such as at the time of shifting of the MT vehicle or the inflection point of the vehicle speed mode, the denominator Since some γ becomes 0, there is a problem that it becomes unstable.

  Accordingly, an object of the present invention is to provide a performance evaluation method and an apparatus thereof that are stable and absolute in any chassis dynamo system.

A first aspect of the present invention is a chassis dynamometer in which an equivalent inertial mass to be tested of a vehicle is set. The vehicle is mounted on the chassis dynamometer and signals detected by a speed detector and a torque detector are used. In what evaluates the load applied to the vehicle from the chassis dynamometer through the evaluation device,
The speed detection signal and the torque signal measured by the speed detector and the torque detector are directly introduced from the chassis dynamometer to the evaluation device, and preset driving resistance parameters and a mechanical loss signal are input, and these driving resistances are input. The driving value, the work rate, and the work amount in the vehicle mode operation state are calculated by the evaluation value calculation unit using the parameters, the mechanical loss signal, and the speed detection signal, and the dynamometer is calculated based on the calculated value. It is characterized by evaluating the load state.
According to a second aspect of the present invention, a load evaluation unit is provided in the evaluation device, the difference value between the target value of the driving force or power and the actual measurement value is displayed on the load evaluation unit, and the load evaluation unit is used for pass / fail judgment. A bandwidth is displayed, and whether or not a difference value between the target value and the actual measurement value is within the bandwidth is evaluated in real time.
A third aspect of the present invention is a chassis dynamometer in which an equivalent inertial mass of a vehicle to be tested is set, and includes a speed detector, a torque detector, a running resistance setting unit, and a mechanical loss setting unit for measurement. In the dynamometer,
A speed signal conversion unit that introduces a signal detected by the speed detector and converts it into a speed detection signal Vm, and a least square approximation that converts the converted speed conversion signal Vm into an acceleration signal dVm / dt. A differential calculation unit, a torque signal conversion unit that introduces a torque signal detected by the torque detector to obtain a roller surface conversion value FLC, a parameter of a running resistance to which a preset value is input, and the speed detection signal A target travel resistance calculation unit that calculates a target travel resistance FRL * using Vm, a vehicle mass IW *, and a vehicle weight equivalent inertia force IM signal of the chassis dynamometer are input, and the acceleration signal dVm is input to each signal. Arithmetic unit for multiplying / dt to obtain IW * · dVm / dt and IM · dVm / dt signals, and FLC, dVm / dt, FRL *, IW * · dVm / dt, IM · dVm / dt and inputs And an evaluation value calculation unit for calculating at least one of the evaluation values of the driving force, the work rate, and the work amount of the vehicle by introducing the roller surface conversion value signal FML of the machine loss. is there.
According to a fourth aspect of the present invention, there is provided a load dynamometer for a chassis dynamometer for evaluating any of the evaluation values of the driving force, work rate, and work calculated by the evaluation value calculator. It is what.
According to a fifth aspect of the present invention, the load evaluation unit displays a difference value between the target value of the driving force or power and the actual measurement value, and the load evaluation unit displays a bandwidth for pass / fail judgment, and the target value and It is characterized in that it can be evaluated in real time whether or not the difference value from the measured value is within this bandwidth.
According to a sixth aspect of the present invention, the performance evaluation device is configured separately from the chassis dynamometer system.

  As described above, according to the evaluation apparatus of the present invention, the chassis dynamometer in a vehicle-mounted state can be stably and absolutely evaluated. In addition, because the evaluation is based on the calculation performed by the evaluation device itself without depending on the calculations in the chassis dynamometer system, real-time evaluation is possible for each chassis dynamometer, and the absolute evaluation of the statistical evaluation result data is possible. It can be compared with any chassis dynamometer. Further, by using the least square approximation differential method for the calculation of the acceleration signal of the evaluation device, the torque and acceleration can be obtained synchronously when evaluating the accuracy and response speed of the chassis dynamometer load applied to the vehicle. it can. By adopting the target driving force and the actually measured driving force calculated using the synchronized signals, stable and absolute evaluation can be performed.

FIG. 1 shows a block diagram of the present invention. Reference numeral 1 denotes a chassis dynamometer roller on which driving wheels of the vehicle are placed. Reference numeral 2 denotes a pulse generator (speed detector), and detection signals are output to the running resistance setting unit 4, the mechanical loss setting unit 5, and the electric inertia setting unit 6, respectively. Reference numeral 7 denotes an adder. The output signals of the running resistance setting unit 4, the mechanical loss setting unit 5, and the electric inertia setting unit 6 are added by the adder 7 and output to the torque control unit 8. Reference numeral 3 denotes a torque detector which is output from the load cell or the like to the torque control unit 8. The torque control unit 8 calculates a torque value based on each input signal and controls the chassis dynamometer.
And these 1-8 comprise the chassis dynamometer system 9.

  Reference numeral 10 is an evaluation device, and 11 is an aliasing filter. This filter is for removing a minimum noise so as not to impair the synchronism of the input signal, and the detected torque signal is input to this filter at the time of evaluation calculation. Then, noise removal is performed. An A / D converter 12 converts an analog signal into a digital signal to obtain a torque value (roller surface equivalent value of detected torque) FLC, and the torque signal converter is constituted by 11 and 12. A speed signal conversion unit 13 includes a P / D conversion unit that converts a pulse signal into a digital signal, and converts the speed signal of the dynamometer detected by the speed detector 2 into a digital signal at the time of evaluation calculation. The detection signal is Vm. Reference numeral 14 denotes a least square approximation differential calculation unit which inputs a speed detection signal Vm and converts it into an acceleration signal dVm / dt. The fact that the least square approximation differentiation method is used for differentiating the velocity signal is that, for example, four points of signals sampled in the past with respect to the present and four future values are calculated in order to calculate the present derivative. Is obtained, and a quadratic function is approximated at 9 points including the current sampling value, and a result of performing the current differential operation on the approximated curve is obtained. Therefore, the use of the future value does not cause a phase delay, and only signal smoothing is executed. If the sampling interval is made fine and the result of shifting the future value is used, real-time calculation is possible.

15 is an aliasing filter similar to 11, and at the time of evaluation calculation, the mechanical loss from the mechanical loss setting unit 5 is input to this filter to remove noise. Reference numeral 16 denotes an A / D converter which converts an analog signal into a digital signal to obtain a torque value equivalent to an opportunity loss (mechanical loss torque converted to roller surface) FML. The aliasing filter 15 and the A / D conversion unit 16 are not necessarily required, and a mechanical loss calculation unit 25 is provided, and a mechanical loss parameter (input to the calculation unit 25 via an input means such as a keyboard ( a ′, b ′, c ′...) and the speed detection signal Vm may be used to calculate the torque value FML corresponding to the mechanical loss. Reference numerals 17, 18, 21, and 22 denote multiplication units, and 19 denotes a square calculation unit. The adding section 20 is directly applied with the a term (tire rolling resistance), which is a parameter of running resistance, via the input means. In the multiplying section 17, the term b (mechanical loss), which is a parameter of running resistance. Is input through the input means and multiplied with the speed detection signal Vm. In the multiplication unit 18, the term c (road surface resistance), which is a parameter of running resistance, is input via the input means, and is multiplied by the squared speed signal. The outputs from the multipliers 17 and 18 are added by the adder 20 to obtain a target running resistance value FRL ^* (a + bVm + cVm ² ). In addition, the equivalent inertial mass IW ^* of the target vehicle input via the input means is applied to the multiplication unit 21 to obtain IW ^* · dVm / dt. The multiplier 22 is applied with the mechanical inertia value IM of the chassis dynamometer input via the input means, and IM · dVm / dt is calculated.

The above calculated values are respectively input to the evaluation value calculation unit 23, and the evaluation values FV, FV ^* , WS, WS ^* , W, W ^* are calculated and then output to the load evaluation unit 24 of the chassis dynamometer. Then, XY plotting is performed by using the target values of the driving force and the work rate as indices, and a linear regression process is executed, and the result is displayed on the display unit of the load evaluation unit 24 not shown. And the evaluation apparatus 10 is comprised by these 11-25 separately from the control part of a chassis dynamometer system or a chassis dynamometer system. This evaluation device 10 is connected to the chassis dynamometer system 9 via the input terminal to the speed detector 2 and the torque detector 3 (in some cases, also connected to the mechanical loss setting unit) when the evaluation work is performed. Input a torque signal. Other calculation parameters and the like are input to the evaluation device via the input means.
In the evaluation value calculation unit 23, the driving force FV of the test vehicle measured from the chassis dynamometer can be obtained by equation (1).

Here, FLCC is a force applied by the chassis dynamometer and is obtained by the equation (2), and is obtained by the sum of the roller surface converted value FLC of the torque detector and the roller surface converted value FML of the mechanical loss torque.

Expression (3) is an arithmetic expression of the target vehicle driving force FV ^* , which is the sum of the target vehicle equivalent inertial masses IW ^* · dVm / dt.

Equation (4) is obtained by calculating the target power WS ^* by the product of the target driving force FV ^* and the speed detection value Vm. Equation (5) is obtained from the measured driving force FV and the speed detection value Vm using a chassis dynamometer. The executed work rate WS is obtained. Moreover, (6) Formula (7) Formula is the type | formula which calculated | required the target work W ^* and the work W of the chassis dynamometer from the target work rate calculated | required by (4) Formula (5) formula and an actual measurement work rate, respectively. It is.

In the evaluation device 10, the evaluation value calculation unit 23 calculates the target value and the actual measurement value of the driving force and power using the signals (speed signal and torque signal) measured by the chassis dynamometer and preset constants. . The obtained target value and actual measurement value are input to the load evaluation unit 24, the primary regression process is performed in this evaluation unit, and the difference value between the target value and the actual measurement value is obtained and displayed, and the vehicle mode driving state Evaluation of the load condition of the chassis dynamometer is performed.
Since the energy required for driving the vehicle under test is considered to be a physical quantity closely related to fuel consumption and exhaust gas, we focused on the amount of energy per unit time (work rate) and drove each driving mode. It is intended to evaluate how accurately the load state of the chassis dynamometer works from the work rate for the vehicle under test.
That is, when the target work amount for each travel mode, each travel resistance set value and the set inertia amount is compared with the actually measured work amount, the target value and the actually measured value are obtained in any travel mode, the travel resistance set value and the set inertia amount. Is almost the same, it is presumed that the load state of the chassis dynamometer is working accurately as a whole.
FIG. 2 is a first-order regression diagram based on the target driving force and the measured driving force obtained by the evaluation calculation unit 23, and FIG. 3 is a first-order regression diagram based on the target power and the measured power. Standard deviation, correlation coefficient, regression line slope, regression line y-intercept, etc. are considered as primary regression evaluation items for driving force and power. For example, the correlation coefficient and regression line slope are tested. The engine is classified according to whether the engine is hot or cold and plotted on FIGS. 2 and 3, and whether the load condition is good or not is determined based on whether or not it matches the regression line slope.
The responsiveness of the load state can be evaluated by the variation of the plot and the standard deviation, and the performance is judged by the slope of the regression line and the correlation coefficient.

FIG. 4 shows an example in which a test vehicle model is created using commercially available software, and the validity of the present invention is verified by performing a linear regression evaluation by simulation. FIG. 4 shows a case of a vehicle weight of 2500 kg, (a) the figure shows the electric inertia response 0.1 s, (b) the figure shows 0.5 s, (c) the figure shows each waveform in the case of 1 s, Each figure shows the vehicle speed, the target value and the measured driving force, and the difference value between the target value and the measured driving force from the top, respectively, and from this simulation result, the target driving force and the measured driving force, the target power and the measured power, FIG. 5 and FIG. 6 are obtained by plotting as XY.
FIG. 5 shows the driving force, FIG. 6 shows the power, FIG. 6A shows the case where the electric inertial response is 0.1 s, FIG. 5B shows the case where the electric response is 0.5 s, and FIG. Indicates the case where the electrical response is 1 s, and broken lines (a) and (b) indicate the bandwidth displayed on the load evaluation unit to enable real-time evaluation during vehicle mode operation, and the plot falls within this bandwidth. If it falls off, it is judged as good.
That is, when the electric inertia response is 0.1 s in FIG. 4A, the difference value between the target value and the actually measured drive value is within 500 N at the maximum, but greatly exceeds 500 N when the electric inertia response is 0.5 s or more. Yes. Bandwidths indicated by broken lines a and b are set to a width corresponding to, for example, 500N. Therefore, as is apparent from FIGS. 5 and 6, the plot when the electric inertia response is 0.1 s is the most consistent with the slope of the regression line and is within the bandwidth, and the plot becomes longer as the electric inertia response time becomes slower. There are many variations in the area, and the band is out of the bandwidth. From this result, it is possible to confirm the response of the electric inertia which is one of the load elements of the chassis dynamometer.
As described above, according to the present invention, the concept of driving force and power can be introduced, and the linear regression equation can be obtained and statistically evaluated to perform an accurate evaluation of the load absorption function. It is.

The block diagram which shows embodiment of this invention. Primary regression evaluation diagram based on target driving force-detected driving force. Primary regression evaluation chart based on target power-detected power. Waveform diagram during primary regression evaluation by simulation, with electric inertial response of 0.1 s Waveform diagram at the time of linear regression evaluation by simulation, when electric inertia response is 0.5 s Waveform diagram at the time of primary regression evaluation by simulation, when electric inertial response is 1 s A linear regression diagram based on a target driving force-detected driving force based on a simulation result, (a) at an electric inertia response of 0.1 s, (b) at an electric inertia response of 0.5 s, and (c) at an electric inertia response of 1 s. . Target regression rate based on simulation result-first-order regression diagram based on detected power, (a) when electrical inertial response is 0.1 s, (b) when electrical inertial response is 0.5 s, and (c) when electrical inertial response is 1 s .

Explanation of symbols

1 ... Laura
2 ... Speed detector
3 ... Torque detector
4 ... Running resistance setting section
5 ... Mechanical loss setting part
6 ... Electric inertia setting part
7 ... Adder
8 ... Torque control unit
10. Evaluation device
11, 15 ... Aliasing filter
12, 16 ... A / D conversion unit 14 ... Least square differential calculation unit
17, 18, 21, 22... Multiplication unit
23. Evaluation value calculation unit
24 ... Load evaluation section

Claims (6)

A chassis dynamometer in which an equivalent inertial mass of a vehicle is set. The vehicle is mounted on the chassis dynamometer, and a signal detected by a speed detector and a torque detector is applied to the vehicle from the chassis dynamometer. In what evaluates the load through the evaluation device,
The speed detection signal and the torque signal measured by the speed detector and the torque detector are directly introduced from the chassis dynamometer to the evaluation device, and preset driving resistance parameters and a mechanical loss signal are input, and these driving resistances are input. The driving value, the work rate, and the work amount in the vehicle mode operation state are calculated by the evaluation value calculation unit using the parameters, the mechanical loss signal, and the speed detection signal, and the dynamometer is calculated based on the calculated value. A method for evaluating the performance of a chassis dynamometer characterized by evaluating the load state of the vehicle. A load evaluation unit is provided in the evaluation device, and the load evaluation unit displays a difference value between a target value and an actual measurement value of driving force or power, and displays a bandwidth for pass / fail determination in the load evaluation unit, The method for evaluating the performance of a chassis dynamometer according to claim 1, wherein whether or not a difference value between the target value and the actual measurement value is within the bandwidth is evaluated in real time. A chassis dynamometer in which an equivalent inertial mass of a vehicle is set, and a speed dynamometer for measurement, a torque detector, a running resistance setting unit, and a mechanical loss setting unit.
A speed signal conversion unit that introduces a signal detected by the speed detector and converts it into a speed detection signal Vm, and a least square approximation that introduces the converted speed conversion signal Vm and converts it into an acceleration signal dVm / dt. A differential calculation unit, a torque signal conversion unit that introduces a torque signal detected by the torque detector to obtain a roller surface conversion value FLC, a parameter of a running resistance to which a preset value is input, and the speed detection signal A target travel resistance calculation unit that calculates a target travel resistance FRL * using Vm, a vehicle mass IW *, and a vehicle weight equivalent inertia force IM signal of the chassis dynamometer are input, and the acceleration signal dVm is input to each signal. Arithmetic unit which multiplies / dt to obtain IW * · dVm / dt and IM · dVm / dt signals, FLC, dVm / dt, FRL *, IW * · dVm / dt, IM · dVm / dt and inputs A chassis dynamo characterized by comprising an evaluation value calculation unit for calculating at least one of the evaluation values of the driving force, the work rate, and the work amount of the vehicle by respectively introducing the roller surface converted value signal FML of the machine loss Meter performance evaluation device. 4. The chassis according to claim 3, further comprising a load dynamometer load evaluation unit for evaluating an evaluation value of any one of the driving force, power, and work calculated by the evaluation value calculation unit. Dynamometer load condition evaluation device. The load evaluation unit displays a difference value between the target value of the driving force or the power factor and the actual measurement value, and displays a bandwidth for pass / fail judgment on the load evaluation unit, and the difference value between the target value and the actual measurement value is 5. The chassis dynamometer performance evaluation apparatus according to claim 4, wherein the performance evaluation apparatus can be evaluated in real time as to whether or not it is within the bandwidth. 6. The chassis dynamometer performance evaluation apparatus according to claim 3, wherein the performance evaluation apparatus is configured separately from the chassis dynamometer system.

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