JP2002214083A - Apparatus for measuring steering stability of vehicle, recording medium having steering stability evaluation program recorded thereon and steering stability evaluation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acculately evaluate the steering stability of a vehicle on the basis of a quantitative index. SOLUTION: Steering force Fh and rudder angle quantity θ are detected, and positive steering work being the integrated value of a section becoming positive in steering power and negative steering work being the integrated value of a section becoming negative are respectively operated in the distribution of steering power (dθ/dt.Fh) with respect to a time axis. A negative steering work ratio being a ratio of negative steering work to positive steering work is operated, and the steering stability of the vehicle is evaluated on the basis of the negative steering work ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle stability evaluation apparatus for evaluating vehicle stability, a recording medium on which a stability evaluation program is recorded, and a stability evaluation method.

[0002]

2. Description of the Related Art Conventionally, as an evaluation of vehicle stability,
Feeling evaluation is known. In this feeling evaluation, the driver driving the vehicle to be evaluated evaluates the operability of the vehicle based on his / her own sensitivity.

[0003]

According to the above-mentioned feeling evaluation, it is possible to evaluate the stability of the vehicle with a certain degree of reliability. However, it is difficult to use the result of the above-mentioned feeling evaluation as a quantitative index for the drivability of the vehicle. If there is a quantitative index for maneuverability, for example, it will be easier to evaluate and compare the maneuverability of different vehicles, and to more accurately and multilaterally improve the maneuverability of vehicles. It is considered that it can be evaluated.

[0004] Therefore, it is known to evaluate the stability of the vehicle by using, for example, a lateral acceleration (lateral G), a yaw rate, and the like generated while the vehicle is running.

[0005] However, when the lateral G and the yaw rate are used as indices, the drivability during turning of the vehicle can be accurately evaluated. )) Has a disadvantage that the detection values of the lateral G and the yaw rate become extremely small, so that accurate evaluation becomes extremely difficult.

[0006] The present invention has been made in view of such circumstances, and an object of the present invention is to accurately evaluate the vehicle stability using a quantitative index.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention focuses on the amount of work that a driver is receiving from outside for steering of a steering wheel due to irregular road surface and the like. Steering performance was evaluated using the steering power, which is the product of the differential value (steering speed) and the steering force, as an index.

[0008] More specifically, the invention according to claim 1 is directed to a drivability evaluation apparatus for evaluating drivability of a vehicle, and a steering force applied by a driver to a steering wheel of the vehicle while the vehicle is running. Is detected by a torque amount between the steering wheel and the wheel or by a myoelectric potential of the driver, a steering angle amount detecting unit that detects a steering angle amount of the steering wheel, and the steering force detecting unit Calculating means for calculating a steering power, which is a product of the time differential value of the steering angle amount and the steering force, based on the detection data of the steering angle and the detection data of the steering angle amount detecting means; And an output means for outputting the information.

According to the first aspect of the present invention, it is possible to accurately evaluate the negative steering power and the vehicle stability based on the steering power calculated by the calculating means.

That is, when the steering power is negative, the direction of the steering wheel speed (the time differential value of the steering angle) and the direction of the steering wheel force are opposite to each other. You are trying to stop. Therefore, a negative steering power means that the vehicle receives work from the outside due to irregular road surface or the like. Therefore, the stability of the vehicle can be evaluated based on the magnitude of the negative steering power.

Here, the steering power is a product of the time differential value of the steering angle amount and the steering force. Therefore, in a vehicle having a heavy steering wheel, both the positive and negative steering powers are used. It gets bigger. For this reason, there is a case where the steering performance of the vehicle cannot be accurately evaluated due to the influence of the weight of the steering wheel only by the magnitude of the steering power.

Therefore, as claimed in claim 2, the calculation means includes a positive steering work which is an integral value of a section where the steering power is positive in a distribution of the steering power with respect to a time axis; The negative steering work, which is the integral value of the section where the rate is negative, may be calculated, and the negative steering work ratio, which is the ratio of the negative steering work to the positive steering work, may be calculated. Good.

That is, since the negative steering work ratio is a ratio of the negative steering work to the positive steering work, the influence of the steering wheel weight is canceled. For this reason, the negative steering work ratio accurately represents how much work is received from the outside regarding the steering of the steering wheel. Therefore, by performing the evaluation of the vehicle stability based on the negative steering work ratio calculated by the calculation means, it is possible to more accurately evaluate the vehicle stability.

Here, since the negative steering work ratio is an integral value, it is necessary to appropriately set an integral section. That is, for example, the traveling state of the vehicle is significantly different between when the vehicle is traveling straight and when the vehicle is turning. For this reason,
Since the value of the negative steering work ratio obtained by integrating the detection data in the integration section including both of these states includes data at the time of different driving states, the operation of the vehicle is controlled. Sex cannot be evaluated accurately.

Therefore, according to a third aspect of the present invention, parameter detection means for detecting the values of various parameters while the vehicle is traveling, detection data of the steering force detection means and steering control based on the detection values of the parameter detection means. It is preferable that the apparatus further comprises a data extracting unit for extracting predetermined data from the detection data of the angular amount detecting unit, and the arithmetic unit is configured to perform an arithmetic operation based on the data extracted by the data extracting unit.

Thus, as described above, it is possible to calculate only the negative steering work ratio by extracting only the data in a certain running state, and to calculate the negative steering work ratio by the negative steering work ratio. It is possible to accurately evaluate gender.

The extraction of the data is effective not only for setting the integral section of the negative steering work ratio but also for more accurately evaluating the steering stability.

In other words, when evaluating the driving stability, specific driving conditions to be evaluated (for example, driving conditions such as running straight ahead at a predetermined vehicle speed) are set in advance, and the driver is required to satisfy the driving conditions. Normally, data is acquired by driving the vehicle, but by providing the parameter detecting means as described in claim 3, data satisfying the traveling conditions to be evaluated is extracted from the obtained data. It becomes possible. This eliminates the need for the driver to drive the vehicle so as to satisfy the driving conditions, prevents intentional elements from being included in the acquired data, and enables the drivability to be more accurately evaluated. Become. Further, it is not necessary to change the running conditions and drive the vehicle many times in order to obtain the data under the necessary running conditions, so that the data can be obtained more efficiently.

Here, the parameter detecting means is configured to detect the vehicle speed, and the data extracting means is configured to extract data when the vehicle speed is constant. You may.

Alternatively, for example, the parameter detecting means may be configured to detect a value of a parameter indicating a turning state of the vehicle, and the data extracting means may be configured to detect the parameter value. May be configured to extract data when the vehicle is in the turning state.

Further, the invention according to claim 6 is an invention effective when comparing the stability evaluation with respect to vehicles (vehicle types) different from each other, and more specifically, the steering according to the vehicle characteristics. Data correction means for correcting the detection data of the force detection means and the detection data of the steering angle amount detection means is provided, and the calculation means is configured to perform a calculation based on the data corrected by the data correction means. That is a specific matter.

That is, the steering force and the steering speed applied to the steering wheel by the driver vary depending on the vehicle characteristics such as the steering gear ratio of the vehicle and the roll characteristics of the vehicle.
For example, when the roll angle is large, the steering force of the driver increases accordingly. For this reason, when the detection data is not corrected in accordance with the vehicle characteristics, the effect of the vehicle characteristics is included in the calculation result (steering power or negative steering work ratio) of the calculation means, which is an index of stability evaluation. It will be lost. As a result, when comparing the stability evaluations of different vehicles, accurate comparison cannot be performed.

Therefore, the data correcting means corrects the detected data in accordance with the vehicle characteristics, and the calculating means calculates the steering power or the negative steering work based on the corrected data. By calculating the percentage,
The effect of the vehicle characteristics is excluded from the obtained calculation result. This makes it possible to make an accurate comparison when comparing the stability evaluations of different vehicles.

Here, the data correction means may be configured to correct the detected data according to the steering gear ratio of the vehicle.

Further, for example, the data correction means may be configured to correct the detection data according to the roll characteristics (spring characteristics, damper characteristics) of the vehicle.

Further, the detection data may be corrected according to, for example, a power steering characteristic (steering force characteristic).

According to a ninth aspect of the present invention, the output means is configured to be capable of outputting operation results of different vehicles in comparison with each other.
As a result, it is possible to easily recognize a difference in the evaluation result of the stability of different vehicles.

[0028] The invention according to claims 10 to 28 is directed to a recording medium on which a vehicle stability evaluation program is recorded. A reading step of reading detection data of a steering force applied by a driver to a steering wheel of the vehicle and detection data of a steering angle amount of the steering wheel, detected during traveling of the vehicle; and a reading step of reading in the reading step. A calculation step of calculating a steering power, which is a product of the time differential value of the steering angle amount and the steering force, based on data; and an output step of outputting at least a calculation result of the calculation step. It is a specific matter.

According to the eleventh aspect of the present invention, the calculating step includes: a positive steering work which is an integral value of a section where the steering power is positive in a distribution of the steering power with respect to a time axis; Calculate the negative steering work, which is the integral value of the section where the rate is negative, and calculate the negative steering work ratio, which is the ratio of the negative steering work to the positive steering work. Matters.

Further, according to a twelfth aspect of the present invention, the drivability evaluation program reads predetermined data from the read data read in the reading step based on detection values of various parameters detected while the vehicle is running. A specific matter is that the calculation step is a step of performing a calculation based on the data extracted in the data extraction step, provided with a data extraction step to be extracted.

According to the thirteenth aspect of the present invention, the data extraction step is a step of extracting data when the vehicle speed is constant, with the parameter being the vehicle speed. The described invention has a specific feature that the data extraction step is a step of extracting data when the vehicle is in a predetermined turning state, with the parameter as a parameter indicating the turning state of the vehicle.

According to a fifteenth aspect of the present invention, the operation stability evaluation program is provided with a data correction step for correcting the read data read in the read step in accordance with the vehicle characteristics. A specific step is to perform an operation based on the data corrected in the data correction step.

The invention according to claim 16 is characterized in that the data correction step is a step of correcting the read data in accordance with the steering gear ratio of the vehicle. In the invention, it is a specific matter that the data correction step is a step of correcting the read data according to the roll characteristics of the vehicle.

According to the tenth to seventeenth aspects, the same operations and effects as those of the first to eighth aspects can be obtained, and the steering power or the negative power calculated in the calculation step can be obtained. Based on the steering work rate of
In addition to being able to accurately evaluate vehicle operability, the data extraction step enables more accurate evaluation of vehicle operability, and the data correction step enables
Stability evaluations of different vehicles can be accurately compared.

The eighteenth to twenty-eighth aspects of the present invention relate to an output step in the stability evaluation program, and relate to an output form in the output step. That is, the output step is as described in claim 18.
The step of displaying the read data read in the reading step may be displayed on a screen. The output step may be a step of displaying a calculation result of the steering power on a screen. Claim 20
As described above, the output step may be a step of displaying the calculation result of the negative steering work ratio on the screen.

The output step may be a step of displaying, on a screen, a diagram representing a correlation between a calculation result of the calculation step and a feeling evaluation point evaluated by the driver.

According to the twenty-first aspect of the present invention, by displaying a diagram showing the correlation between the operation result of the operation step and the feeling evaluation point evaluated by the driver, the operation of the operation step is determined by the presence or absence of the correlation between the two. The reliability of the result (steering power rate or negative steering work rate) can be confirmed.

Here, the degree of the evaluation of the feeling evaluated by the driver may be different for each driver. For example, a certain driver tends to give a higher evaluation, while another driver has a lower evaluation. Can tend to give

Therefore, for example, the output step is displayed on the screen by comparing a diagram showing the correlation between the calculation result and the feeling evaluation point evaluated by the driver for different drivers. You may.

Thus, the feeling evaluation points evaluated by different drivers are compared with each other based on the calculation results, and
If it can be determined that the degree of evaluation is different for each driver, correctness of the feeling evaluation point is realized to realize an accurate drivability evaluation.

The output step may be a step of displaying, on a screen, a distribution of the calculation results of the calculation steps for the values of various parameters detected during traveling.

Further, in the invention according to claim 24, the output step may be a step of adding a calculation result of the calculation step to a map indicating a traveling locus of the vehicle and displaying the result on a screen.

According to the twenty-fourth aspect of the present invention, it is possible to visually compare the running state of the vehicle (for example, when the vehicle is going straight or turning) and the calculation result, and to recognize the running state and the running environment. This makes it possible to evaluate and analyze maneuverability.

Further, the output step may be a step of adding the detected values of various parameters to a map indicating the traveling locus of the vehicle and displaying the detected values on a screen.

According to a twenty-sixth aspect of the present invention, the output step displays the calculation result and the values of various parameters corresponding to the position of the designated traveling locus in accordance with the designation on the traveling locus of the vehicle by the operator. May be displayed.

According to the twenty-fifth or twenty-sixth aspect of the present invention, the data relating to the stability evaluation can be analyzed more diversified, and the stability evaluation can be performed more accurately.

According to a twenty-seventh aspect, the output step may be a step of comparing calculation results of different vehicles with each other and displaying the result on a screen. This makes it possible to see at a glance the difference in the evaluation results of the stability for different vehicles.

According to a twenty-eighth aspect of the present invention, the calculation step is a step of performing a calculation while the vehicle is running, and the output step is notified when the calculation result of the calculation step exceeds a predetermined threshold value. It is a step.

That is, when the calculation result of the calculation step exceeds a predetermined threshold value, it is a time when the stability of the vehicle is poor, and it is determined that the calculation result exceeds the predetermined threshold value while the vehicle is running. The notification enables the driver or the like of the vehicle to recognize the traveling state and the traveling environment when the steerability is determined to be poor. As a result, it is possible to compare and recognize the traveling state of the vehicle and the calculation result as described in claim 24, and to evaluate and analyze the stability based on the traveling state and the traveling environment. Become.

The invention according to claim 29 is directed to a stability evaluation method for evaluating the stability of a vehicle, wherein a steering force applied by a driver to a steering wheel of the vehicle while the vehicle is running is:
By the amount of torque between the handle and the wheel,
Or, a steering force detecting step of detecting by a myoelectric potential of the driver, a steering angle amount detecting step of detecting a steering angle amount of the steering wheel, and detection data in the steering force detecting step and detection data in the steering angle amount detecting step. An operation step of calculating a steering power, which is a product of the time differential value of the steering angle amount and the steering force, based on the calculation result in the operation step. And a step.

According to a thirtieth aspect of the present invention, in the calculation of the steering power distribution with respect to the time axis, the steering step is a positive steering work which is an integral value of a section where the steering power is positive. Calculate the negative steering work, which is the integral value of the section where the rate is negative, and calculate the negative steering work ratio, which is the ratio of the negative steering work to the positive steering work. Matters.

According to the invention of claim 29 and claim 30, according to the invention of claim 1 and claim 2, respectively.
In addition, the same operations and effects as those of the tenth and eleventh aspects are obtained.

[0053]

As described above, according to the vehicle stability evaluation apparatus, the recording medium storing the stability evaluation program, and the stability evaluation method of the present invention, the steering power or the negative steering is evaluated. It is possible to accurately evaluate the vehicle's maneuverability based on the work ratio.

[0054]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a vehicle stability evaluation apparatus A according to an embodiment of the present invention, which comprises a steering force detecting means for detecting various parameters for a vehicle 1 to be evaluated, An angle amount detecting means and a parameter detecting means are provided, and the operability of the vehicle is evaluated based on the detection results of these detecting means.

A description will now be given of each of the detection means.
The steering wheel 1 for detecting a steering force applied to the steering wheel 1
A torque sensor 21 is provided as steering force detecting means for detecting a torque amount between the wheel 1 and the wheel 12, and a steering angle sensor 22 is provided as steering angle amount detecting means for detecting a steering angle of the steering wheel. ing.

As parameter detection means, a vehicle speed sensor 23 for detecting the vehicle speed of the vehicle 1, a lateral G sensor 24 for detecting a lateral acceleration (lateral G) and a longitudinal acceleration (longitudinal G) acting on the vehicle, and a longitudinal G sensor 24 A sensor 25 and a yaw rate sensor 26 for detecting a yaw rate of the vehicle 1 are provided.

Further, as a parameter detecting means, a vehicle height sensor 27 for detecting the roll speed and roll balance of the vehicle 1, a pedal sensor 28 for detecting depression of an accelerator pedal by a driver, and a G sensor attached to a suspension. In addition, an upper and lower G sensor 29 for detecting irregular road surface is provided.

In addition, a wind pressure sensor 30 for detecting the wind pressure on the vehicle 1 is provided as a parameter detecting means, and this wind pressure sensor 30 may be constituted by a pitot tube, for example.

A myoelectric potential sensor 31 attached to the driver and detecting myoelectric potential of the arm is provided as parameter detecting means. The detection site of the myoelectric potential may be, for example, a triceps brachii, ulnar carpi flexor, flexor carpal extensor, or the like. Since the steering force of the steering wheel can be detected using the detected value of the myoelectric potential sensor 31, the myoelectric potential sensor 31 may be used as a steering force detecting means instead of the torque sensor 22.

A GPS 32 for detecting the position of the vehicle 1 is provided as a parameter detecting means, and the running trajectory of the vehicle 1 when the above various parameters are detected based on the detection result of the GPS 32 is detected. It is configured to be.

As a parameter detecting means, a feeling switch 33 for inputting an evaluation point of stability evaluated by a driver is provided, and this feeling switch 33 is operated by the driver itself. Alternatively, the experiment may be performed by an experimenter who gets on the vehicle 1. The feeling switch 33
Is not limited to an operation switch as long as it is possible to input a stability evaluation point evaluated by a driver.

The various sensors 21 to 33 are respectively connected to a storage unit 41. The storage unit 41 stores the detection values of the various sensors 21 to 33 and the like in time series on the same time axis. It is configured to be memorable as. The storage unit 41 may be configured by a dedicated device, or may be configured by, for example, a personal computer (PC).

Further, a PC 43 is provided outside the vehicle 1, and a stability evaluation program is incorporated in the PC 43, and as will be described later, the storage unit 4 is provided.
1 is configured to be able to read the detection data stored in the storage medium 1 via a recording medium 42 such as a CD-ROM. Although the PC 43 is provided outside the vehicle 1 in the illustrated example, the PC 43 may be provided inside the vehicle 1 as, for example, a portable PC (a so-called notebook PC). In this case, the notebook PC may be configured to also serve as the storage unit. The PC 43 is not limited to a PC as long as it executes a stability evaluation program described later.

The above-mentioned stability evaluation program is, for example, a CD.
A reading step of reading detection data recorded on the recording medium 42 and a detection step of various parameters (vehicle speed, lateral G, etc.) A data extraction step of extracting predetermined data from the read data (steering force and steering angle) read in the reading step; and a data extraction step in accordance with vehicle characteristics such as a steering gear ratio and a roll characteristic. And a steering power, which is a product of the time differential value of the steering angle amount and the steering force, based on the data corrected in the data correction step, and a positive steering of the negative steering work. A calculation step for calculating a negative steering work ratio, which is a ratio to work, and at least a calculation result of the calculation step is displayed on a screen. Or, and an output step or recorded on a paper medium. Therefore, the above CD-ROM
A recording medium on which a stability evaluation program is recorded is constituted by 44, and a data extraction means, a data correction means, a calculation means and an output of the stability evaluation apparatus A are provided by a PC 43 incorporating the stability evaluation program. Means are configured. The recording medium on which the stability evaluation program is recorded is not limited to the CD-ROM, but may be another recording medium.

Next, a description will be given of a drivability evaluation method according to the drivability evaluation program. The drivability evaluation method is particularly suitable for evaluating the instability of a vehicle. The evaluation of maneuverability (direct security) is made.

That is, as shown in FIG. 2, the direction of the steering speed (the differential value of the steering angle) (see the solid line in FIG. 2) and the direction of the steering force (see the broken line in FIG. 2) Positive steering work, which is the same direction, and negative steering work, in which the direction of the steering wheel speed and the direction of the driver's steering force are opposite to each other, can be divided into the positive steering work that the driver desires. In contrast to the steering at the time of turning when the steering wheel 11 is steered in the direction, the negative steering work is the steering due to a disturbance in which the driver tries to stop the movement of the steering wheel 11. As described above, the “negative steering work ratio” is the ratio of negative steering work to positive steering work (negative steering work / positive steering work). It can be understood how much the driver tries to stop the movement of the steering wheel 11 while the vehicle is running. That is, when the ratio of the negative steering work is small, the ratio at which the driver stops the movement of the steering wheel 11 is small, in other words, when the correction steering for the disturbance is small, it can be evaluated that the steering stability is high. When the steering work ratio of the driver is high, the driver stops the movement of the steering wheel 11 at a high ratio, in other words, when there is a large amount of correction steering for disturbance, it can be evaluated that the stability is low.

Next, the stability evaluation program will be described in detail with reference to FIG. 3. First, step S1 is a reading step, which is stored in the storage unit 41 of the vehicle 1 and is stored in the storage medium. The detection data of various sensors 21 to 33 recorded in 42 is read.

The following step S2 is a filtering step, which is performed in step S1.
Is a step of performing noise processing on the data read in. Specifically, regarding the data of the steering angle amount and the steering force (steering torque amount), the steering wheel steering frequency of the driver is considered to be lower than a predetermined frequency (first frequency), and therefore, the first frequency or more. Is removed by a low-pass filter. Note that, for example, when the vehicle is traveling on a winding road, the data of the steering wheel frequency associated with the road shape, that is, when traveling on a curve is included. Therefore, data having a frequency higher than the predetermined frequency (second frequency) may be data obtained by steering the steering wheel while traveling on a curve or the like, and the data having the second frequency or lower may be removed by a high-pass filter. . Therefore, in the above filter processing, processing by a band pass filter may be performed. The first and second frequencies may be set as appropriate.

Step S3 is an offset processing step. This offset processing is processing for correcting a zero point (reference point). Regarding the steering speed, the yaw rate, the lateral G, the front and rear G, the roll speed, the roll angle, and the vehicle speed, the detected values obtained when the vehicle 1 is stopped horizontally are each set to a zero point, and each of the filtered detection values is used. What is necessary is just to correct the zero point with respect to the data. As for the steering force, a value when the driver has released his / her hand from the steering wheel 11 may be set as a zero point, and the zero point may be corrected for the filtered steering force data.

The offset processing is not limited to the stopped state. For example, the detected value of the yaw rate or the like when the vehicle is traveling straight at a predetermined vehicle speed is set as a zero point, Point correction may be performed. Thus, for a vehicle or the like in which the steering angle when going straight ahead deviates from the neutral point due to, for example, wheel alignment or the like, the offset processing can be appropriately performed.

Step S4 is a data extraction step. This data extraction is based on the detection data of the various sensors 21 to 33, based on the data of the steering speed and the steering force subjected to the filtering process and the offset process. This is the process of extracting the data. That is, as will be described later, since the positive steering work and the negative steering work are obtained by integrating the distribution data of the steering power with respect to the time axis, the data of the section where the traveling conditions and the like are constant are obtained. It is necessary to extract and perform integral operation. For example, the traveling state of the vehicle is significantly different between when the vehicle is traveling straight and when it is turning, but the value of the negative steering work ratio calculated by integrating in the integration section including both these states is However, the data in different driving states are included, and it is not possible to accurately evaluate the operability of the vehicle.

As described above, since it is necessary to extract data of a section where the running conditions and the like are constant, in the data extraction step, for example, when evaluating the safety, the vehicle is traveling straight. Extract the data at the time. That is, data is extracted when the vehicle speed is within the predetermined range and the longitudinal G is equal to or less than the predetermined value, and the data in which the amplitude of the steering angle amount is equal to or less than the predetermined range. At this time, the predetermined range of the amplitude of the steering angle amount may be changed according to the vehicle speed (the higher the vehicle speed, the smaller the predetermined range).
Note that instead of the extraction condition that the amplitude of the steering angle amount is equal to or smaller than a predetermined range, data in which the vehicle is traveling straight ahead is extracted even if data in which the lateral G is equal to or smaller than a predetermined value is extracted. be able to.

To extract data when the vehicle is turning, for example, data when the lateral G or the yaw rate is within a predetermined range may be extracted. The conditions for extracting the detection data are not limited to these.

Extracting data in this way is not only effective for performing the integral operation properly, but also effective for more accurately evaluating the stability.

That is, in the evaluation of drivability, specific driving conditions to be evaluated (for example, driving conditions such as running straight ahead at a predetermined vehicle speed) are set in advance, and the driver sets the vehicle so as to satisfy the driving conditions. It is normal to drive 1 and acquire data. By extracting data that satisfies the driving conditions to be evaluated from the obtained data,
The driver does not need to drive the vehicle 1 so as to satisfy the driving conditions. As a result, it is possible to prevent intentional elements from being included in the acquired data, and it is possible to more accurately evaluate the drivability. In addition, in order to obtain detection data under necessary driving conditions, it is not necessary to change the driving conditions and drive the vehicle 1 many times, so that it is possible to more efficiently obtain data related to the evaluation of drivability. it can.

Step S5 is a data correction step. This data correction is a process of correcting the detection data according to the vehicle characteristics. Thereby, since the criteria of the vehicle characteristics of the different vehicles match each other, it is possible to appropriately compare the stability evaluations of the different vehicles.

More specifically, for example, when the lateral G is large, the steering force by the driver increases by that amount, so that the steering force is reduced in accordance with the magnitude of the lateral G.

Further, even when the roll angle is large, the steering force by the driver is increased by that amount. Therefore, a correction for reducing the steering force according to the magnitude of the roll angle (according to the roll characteristics) is performed.

Further, since the steering speed varies depending on the steering gear ratio (steering speed characteristic) of the vehicle, for example, the steering angle amount required to generate a predetermined lateral G in the vehicle to be evaluated is determined by the steering angle during turning. The steering speed data is corrected in accordance with the ratio between the calculated steering angle amount and a preset reference steering angle amount, which is calculated from the relationship between the amount, the lateral G, and the vehicle speed. The correction is performed by calculating a steering angle amount required to generate a predetermined yaw rate from the relationship between the steering angle amount, the yaw rate, and the vehicle speed during turning, and calculating the calculated steering angle amount and the set reference steering angle. The steering speed data may be corrected according to the ratio with the amount.

Further, since the steering force varies depending on the power steering characteristic (steering force characteristic), for example, the steering force required to generate a predetermined lateral G in the vehicle to be evaluated is determined by the steering angle amount and the lateral G during turning. Calculated from the relationship between
The steering force data is corrected according to the ratio between the calculated steering force and a preset reference steering force. The correction is performed by calculating a steering force required to generate a predetermined yaw rate from the relationship between the steering angle amount, the yaw rate, and the vehicle speed during turning, and calculating the ratio of the calculated steering force to the reference steering force. The steering force data may be corrected accordingly.

Step S6 is a step of selecting a vehicle to be compared. In this step, the operator of the drivability evaluation apparatus A selects a vehicle to be compared with the vehicle to be evaluated for drivability evaluation. It is a step to do. The data relating to the comparison vehicle may be stored in advance in a storage unit provided in the PC 43, or may be stored in a recording medium.

Step S7 is a calculation step of the steering work. In this step, first, the steering power dW / dt is calculated by the following equation (1).

DW / dt = dθ / dt · Fh (1) Here, W is the steering work, θ is the steering angle, and Fh is the steering force.

Then, in the distribution 6a of the steering power dW / dt with respect to the time axis shown in FIG. 5, a positive steering work is calculated by integrating a section in which the steering power dW / dt is positive. Negative steering work is calculated by integrating the section where the steering power dW / dt is negative (see the hatched portion in the figure).

The following step S8 is a step of calculating the negative steering work ratio. In this step, the ratio of the negative steering work to the positive steering work is calculated. Therefore, the above-described step S7 or step S8 constitutes an operation step.

Step S9 is an output form selection step in which the operator selects from various output forms described later.

Step S10 is an output step.
The calculation result and the like of the calculation step are output in the output mode selected in step S9. That is, the calculation result of the calculation step is displayed on a screen or recorded on a paper medium.

Next, a description will be given of an output form in which the selection is made in step S9. The stability evaluation program is configured to output at least the forms shown in FIGS.

FIG. 4 shows a display mode in which the detection data detected by the various sensors 21 to 33 are displayed as time-series data. In this display mode, a plurality of detection data (steering angle 51 , Steering force 52, yaw rate 53
And the horizontal G54) can be displayed side by side, or, for example, the detection data 5b of the comparative vehicle (vehicle B) selected in step S6 can be displayed side by side with the detection data 5a of the evaluation target vehicle (vehicle A). Is configured.

FIG. 5 shows a display form for displaying the calculation result of the steering power dW / dt. In this display form as well, the calculation result 6b of the comparative vehicle (Car B) is displayed on the vehicle to be evaluated (Car A). ) Can be displayed side by side with the calculation result 6a.

FIG. 6 shows a display form for displaying the calculation result of the negative steering work ratio. The abscissa axis shows running sections divided based on running conditions in chronological order. In this display form, the calculation result of the vehicle to be evaluated (vehicle A) and the calculation result of the comparison vehicle (vehicle B) can be displayed in comparison on the same graph 61. At this time, the calculation result of the vehicle to be evaluated (vehicle A) and the calculation result of the comparison vehicle (vehicle B) may be displayed in different colors, for example.

As described above, in the display modes shown in FIGS. 4 to 6, the detection data and the calculation results of the different vehicles (vehicles A and B) are output in comparison with each other.
Differences between the detection data and the evaluation results of the maneuverability of different vehicles can be seen at a glance.

FIG. 7 shows a display form for displaying a graph 62 showing the correlation between the feeling evaluation point and the negative steering work ratio. By enabling such display, if the graph 62 becomes, for example, a downward-sloping graph, the feeling evaluation point and the result of the negative steering work ratio are correlated with each other. The reliability of the negative steering work rate result can be confirmed. Further, the degree of the feeling evaluation point is defined by an objective evaluation index of the negative steering work ratio, for example, such that seven points of the feeling evaluation correspond to 0.3 of the negative steering work ratio. Becomes possible.

FIG. 8 shows a display form for displaying a graph 63 showing the correlation between the feeling evaluation point and the negative steering work ratio for a plurality of different vehicles (vehicles A to E in the illustrated example). As a result, the difference between the evaluation results of the maneuverability of different vehicles can be recognized at a glance.

Further, the degree of feeling evaluation may be different for each driver. For example, driver a
May tend to give a lower rating while driver b tends to give a higher rating. For this reason, this display mode is configured to be able to display the correlation between the negative steering work ratio and the result of the feeling evaluation for the drivers (drivers a and b) different from each other (see FIG. (See solid and dashed lines),
Thereby, the degree of feeling evaluation between the driver a and the driver b, for example, the driver b
It can be determined that the feeling evaluation tends to be higher than that of. As a result, it is possible to correct the above-mentioned feeling evaluation points so that the criteria of the feeling evaluation points match for each driver. Note that the correlation between the negative steering work ratio and the result of the feeling evaluation for the different drivers is shown in a display form shown in FIG. 7 (the negative steering work ratio and the result of the feeling evaluation for the predetermined vehicle). Can be displayed also in FIG.

FIG. 9 shows a display form for displaying a calculation result distribution 64 of the negative steering work ratio with respect to the detected data of the myoelectric potential. In the example shown in FIG. 3 shows the distribution of the steering work ratio of the vehicle.

As described above, in the relationship between the negative steering work ratio and the myoelectric potential detection data, the upper right region is a region with poor instability, while the lower left region is a region with good instability. However, by performing such a display,
It is possible to judge a relationship between the evaluation of the drivability and the influence on the driver (what part of the driver is under what kind of force).

In this display mode, although not shown, for example, the calculation result of the negative steering work ratio with respect to the detection data of the myoelectric potential is displayed for each detection site, or the calculation result of the detection data of the myoelectric potential is displayed for each of the left and right arms. The calculation result of the negative steering work ratio can be displayed, and the detection data of the different detection parts and the detection data of the left and right arms can be displayed simultaneously in different colors.

Further, a display of the doll 65 is provided. In particular, a portion where the value of the myoelectric potential is large (a portion where a force is applied) is displayed by coloring, for example, so that it can be easily recognized. Is also good.

FIG. 10 shows a display form for displaying the distribution 66 of the negative steering work ratio with respect to the upper and lower sides G. As a result, it is possible to evaluate the maneuverability with respect to the vertical G, that is, the size of the irregular road surface, and as shown in FIG. Can be checked at a glance.

FIG. 11 shows a display form in which the detection result of the various parameters and the calculation result 7a of the negative steering work ratio are displayed on the traveling locus T of the vehicle 1 obtained from the data of the GPS 32. In, the traveling locus is divided into a plurality of sections, and the negative steering work ratio for each section is color-coded stepwise (for example, to 0.2, to .0).
3, -0.4, -0.5, 0.5-). Thereby, the traveling state of the vehicle (for example, a turning or straight traveling state)
At a glance, the correspondence with the negative steering work ratio can be understood, and the stability can be evaluated based on the driving environment. The parameters displayed on the traveling trajectory T are not limited to the negative steering work ratio, but may also include other feeling evaluation points, myoelectric potentials, and the like. The parameter displayed on the traveling locus T can be changed by selecting it in the selection list 72. Further, it is also possible to display the result of the feeling evaluation or the like in each section of the traveling locus T in the vicinity of the traveling locus T by a numeral.
The traveling trajectory T, the negative steering work ratio, and the feeling evaluation can be compared and analyzed in various ways.

In this display mode, when the operator designates the section 71a on the traveling locus T, the time series data of various parameters corresponding to the section (in the example shown, the time series data 71 of the upper and lower G). ) Is displayed. Thereby, the traveling locus T, the irregular road surface,
An analysis can be made in comparison with the negative steering work ratio.

Further, in this display mode, the detection result of the above parameters and the calculation result 7b of the negative steering work rate of the vehicle B compared with the vehicle 7 are displayed on the travel locus T corresponding to the travel locus of the vehicle A to be evaluated. Can be added and displayed, whereby the vehicle A to be evaluated and the comparative vehicle B can be easily compared. By performing such a comparison display, for example, a section in which the negative steering work ratio is high (the steering is poor) in the car A is not high (the steering is good) in the car B at a glance. Will be understood by

In this display mode, in the display 7a for the car A, the calculation result of the negative steering work rate is displayed for all the sections of the traveling locus T. For example, the display 7b for the car B is displayed. It is also possible to display the result only in the section where the calculation result of the negative steering work ratio is a predetermined value or more (the steering stability is relatively poor).

As described above, according to the present invention, accurate evaluation can be performed by evaluating the steerability of the vehicle, particularly the direct stability, using the negative steering work ratio as an index.

Also, by displaying detection data of various parameters related to the evaluation of the stability and calculation results of the steering power and the steering work ratio in various display forms as shown in FIGS. More diverse and accurate evaluation of maneuverability will be possible.

<Other Embodiments> The present invention is not limited to the above-described embodiments, but includes various other embodiments. That is, in the above-described embodiment, the detection data of the various sensors 21 to 33 is stored in the storage unit 41 and is taken into the PC 43 via the recording medium 42.
The negative steering work ratio is detected by the PC 43 while the detection data of the
The calculation may be performed at the same time as the detection in (1) to (33) (while the vehicle is running).

As described above, when calculating the negative steering work ratio in real time while the vehicle is running, for example, a threshold value is set, and when the negative steering work ratio exceeds the threshold value, a sound or the like is generated. May be issued to notify that effect. In this way, the driver or the like can recognize the traveling state and traveling environment when the steerability is reduced while the vehicle 1 is traveling. This results in a negative steering work rate,
Recognition can be made in correspondence with the running condition and environment of the vehicle.
Analysis becomes possible.

In the above-described embodiment, the stability of the vehicle 1 is evaluated using the negative steering work rate as an index. For example, the stability of the vehicle 1 is evaluated using the negative steering power as an index. You may make it evaluate.

However, the steering power dW / dt is given by the following equation (1).
, The steering power dW / dt is a positive or negative value in the vehicle 1 having a heavy steering wheel 11 because it is the product of the time differential value of the steering angle amount θ and the steering force Fh. It gets bigger. For this reason, the steering power dW / dt alone may not be able to accurately evaluate the drivability of the vehicle 1 in some cases. Therefore, the ratio between the negative value and the positive value is obtained.
The use of the negative steering work ratio at which the influence of the steering wheel weight is canceled as an index realizes more accurate vehicle stability evaluation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle stability evaluation apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a positive steering work and a negative steering work.

FIG. 3 is a flowchart showing the contents of a stability evaluation program.

FIG. 4 is a diagram showing an example of a display form according to a stability evaluation program.

FIG. 5 is a diagram showing an example of a display form according to a stability evaluation program.

FIG. 6 is a diagram showing an example of a display form according to a stability evaluation program.

FIG. 7 is a diagram showing an example of a display form according to a stability evaluation program.

FIG. 8 is a diagram showing an example of a display form according to a stability evaluation program.

FIG. 9 is a diagram illustrating an example of a display form according to the stability evaluation program.

FIG. 10 is a diagram showing an example of a display form according to a stability evaluation program.

FIG. 11 is a diagram showing an example of a display mode according to the stability evaluation program.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 vehicle 11 steering wheel 12 wheels 21 steering angle sensor (steering angle amount detecting means) 22 torque sensor (steering force detecting means) 23 vehicle speed sensor (parameter detecting means) 24 lateral G sensor (parameter detecting means) 25 front and rear G sensor (parameter detection) Means) 26 Yaw rate sensor (parameter detecting means) 27 Vehicle height sensor (parameter detecting means) 28 Pedal sensor (parameter detecting means) 29 Vertical G sensor (parameter detecting means) 30 Wind pressure sensor (parameter detecting means) 31 Myoelectric potential sensor (parameter) , Steering force detection means) 32 GPS (parameter detection means) 33 feeling switch (parameter detection means) 43 PC (calculation, output, data extraction, data correction means) 44 CD-ROM (stability evaluation program recorded Recording medium) A Stability evaluation device

Claims (30)

[Claims] 1. A stability evaluation device for evaluating the stability of a vehicle, wherein a steering force applied by a driver to a steering wheel of the vehicle during traveling of the vehicle is generated between the steering wheel and wheels. A steering force detecting means for detecting a torque amount or a myoelectric potential of the driver, a steering angle amount detecting means for detecting a steering angle amount of the steering wheel, a detection data of the steering force detecting means and a steering angle amount detecting means. A calculating means for calculating a steering power, which is a product of the time differential value of the steering angle amount and the steering force, based on the detection data; and an output means for outputting a calculation result of the calculating means. A vehicle stability evaluation device characterized by the above-mentioned. 2. The method according to claim 1, wherein in the distribution of the steering power with respect to the time axis, the calculation means includes: a positive steering work which is an integral value of a section where the steering power is positive; And negative steering work, which is an integral value of the section, and calculating a negative steering work ratio, which is a ratio of the negative steering work to the positive steering work. Vehicle stability evaluation device. 3. The detection data of the steering force detection means according to claim 1 or 2, wherein the parameter detection means detects values of various parameters during traveling of the vehicle, and the detection data of the steering force detection means based on the detection values of the parameter detection means. And data extraction means for extracting predetermined data from the detection data of the steering angle detection means. The calculation means is configured to perform an operation based on the data extracted by the data extraction means. A vehicle stability evaluation apparatus characterized by the above-mentioned. 4. The apparatus according to claim 3, wherein the parameter detecting means is configured to detect a vehicle speed, and the data extracting means is configured to extract data when the vehicle speed is constant. Evaluation device for vehicle stability. 5. The vehicle according to claim 3, wherein the parameter detecting means is configured to detect a value of a parameter indicating a turning state of the vehicle, and the data extracting means is configured to detect data when the vehicle is in a predetermined turning state. A vehicle stability evaluation device configured to extract. 6. The apparatus according to claim 1, further comprising a data correction unit that corrects the detection data of the steering force detection unit and the detection data of the steering angle amount detection unit in accordance with vehicle characteristics. And a calculating unit configured to perform a calculation based on the data corrected by the data correcting unit. 7. The vehicle stability evaluation apparatus according to claim 6, wherein the data correction means is configured to correct the detection data according to a steering gear ratio of the vehicle. 8. The vehicle stability evaluation device according to claim 6, wherein the data correction means is configured to correct the detection data in accordance with the roll characteristics of the vehicle. 9. The output device according to claim 1, wherein the output means outputs a calculation result for vehicles different from each other.
An apparatus for evaluating the stability of a vehicle, wherein the apparatus is configured to be capable of outputting in contrast. 10. A recording medium on which a stability evaluation program for evaluating the stability of a vehicle is recorded, wherein the stability evaluation program detects a driver while the vehicle is running. A reading step of reading the detection data of the steering force to be applied to the steering wheel, and the detection data of the steering angle amount of the steering wheel, and a time differential value of the steering angle amount based on the read data read in the reading step. Recording a vehicle stability evaluation program, comprising: a calculation step of calculating a steering power which is a product of the steering force; and an output step of outputting at least a calculation result of the calculation step. Recording medium. 11. The calculation step according to claim 10, wherein, in the distribution of the steering power with respect to the time axis, the positive steering work, which is an integral value of a section where the steering power is positive, and the steering power is negative. And calculating a negative steering work, which is a ratio of the negative steering work to the positive steering work. A recording medium on which a sex evaluation program is recorded. 12. The stability evaluation program according to claim 10 or 11, wherein the stability evaluation program is configured to convert predetermined data from the read data read in the reading step based on detection values of various parameters detected while the vehicle is running. A data extraction step of extracting a vehicle, wherein the calculation step performs a calculation based on the data extracted in the data extraction step. 13. The recording medium according to claim 12, wherein the parameter is a vehicle speed, and the data extracting step extracts data when the vehicle speed is constant. . 14. The vehicle according to claim 12, wherein the parameter is a parameter representing a turning state of the vehicle, and the data extracting step extracts data when the vehicle is in a predetermined turning state. A recording medium on which a stability evaluation program is recorded. 15. The stability evaluation program according to any one of claims 10 to 12, further comprising a data correction step of correcting read data read in the reading step according to vehicle characteristics. The calculation step includes performing a calculation based on the data corrected in the data correction step. 16. The recording medium according to claim 15, wherein the data correction step corrects the read data according to a steering gear ratio of the vehicle. 17. The recording medium according to claim 15, wherein the data correction step corrects the read data according to a roll characteristic of the vehicle. 18. The recording medium according to claim 10, wherein the output step displays the read data read in the reading step on a screen. 19. The recording medium according to claim 10, wherein the output step displays a calculation result of the steering power on a screen. 20. The recording medium according to claim 11, wherein the output step displays a calculation result of the negative steering work ratio on a screen. 21. The vehicle according to claim 10, wherein the output step displays on the screen a diagram representing a correlation between a calculation result of the calculation step and a feeling evaluation point evaluated by the driver. A recording medium on which a stability evaluation program is recorded. 22. The method according to claim 21, wherein the output step displays on a screen a diagram showing a correlation between a calculation result and a feeling evaluation point evaluated by the driver for different drivers. Recording medium for recording a vehicle stability evaluation program. 23. The vehicle operation system according to claim 10, wherein the output step displays, on a screen, a distribution of a calculation result of the calculation step with respect to detection values of various parameters detected during traveling. A recording medium that records a safety evaluation program. 24. The vehicle operation system according to claim 10, wherein the output step displays a calculation result of the calculation step on a screen by adding the calculation result to a map indicating a trajectory of the vehicle. A recording medium on which a sex evaluation program is recorded. 25. The vehicle stability evaluation program according to claim 24, wherein the output step displays the detected values of the various parameters on a screen after adding the detected values to a map indicating the traveling locus of the vehicle. The recording medium on which it was recorded. 26. An output step according to claim 24 or 25, wherein, in response to a designation on the traveling locus of the vehicle by the operator, a calculation result and various parameters corresponding to the position of the designated traveling locus are detected. A recording medium recording a vehicle stability evaluation program, wherein the value is displayed on a screen. 27. A vehicle stability evaluation program according to any one of claims 19 to 26, wherein the output step displays, on a screen, a calculation result of the vehicle different from each other. The recording medium on which it was recorded. 28. The calculation step according to claim 10, wherein the calculation step performs the calculation while the vehicle is running, and the output step notifies when the calculation result of the calculation step exceeds a predetermined threshold value. A recording medium on which a vehicle stability evaluation program is recorded. 29. A drivability evaluation method for evaluating drivability of a vehicle, the method comprising: applying a steering force applied by a driver to a steering wheel of the vehicle while the vehicle is running, between the steering wheel and the wheel. A steering force detecting step of detecting by a torque amount or by a myoelectric potential of the driver; a steering angle amount detecting step of detecting a steering angle amount of the steering wheel; and a detection data and a steering angle amount detecting step of the steering force detecting step. A calculating step of calculating a steering power, which is a product of the time differential value of the steering angle amount and the steering force, based on the detection data; and An evaluation step of performing an evaluation. 30. The calculation step according to claim 29, wherein, in the distribution of the steering power with respect to the time axis, the positive steering work which is an integral value of a section where the steering power is positive, and the steering power is negative. And calculating a negative steering work, which is a ratio of the negative steering work to the positive steering work. Sex evaluation method.