JPS63117236A - Chassis dynamo for four wheel driven vehicle - Google Patents

Abstract

PURPOSE:To enable the simulating of actual running condition (especially, turning of a four wheel driven vehicle) accurately, by performing an operational control automatically and in real time with a speed difference between right and left wheels taken into account in addition to sharing ratio and speed difference between front and rear wheels. CONSTITUTION:Right and left driven wheels 110a and 110b and 110c and 110d respectively on the front wheel side and the rear wheel side of a four wheel driven vehicle 100 are placed on a pair of rollers 10a and 10b and those 10c and 10d respectively and when they run on the rollers 10 (10-10d), the rollers function as endless flat road in stead of an actual road surface. Based on a computed value of a control circuit 14, dynamometers 12a-12d connected direct to rotating shafts of the rollers 10 are controlled to apply a rotary torque equivalent to an actual running condition to the driven wheels 110 (110a-110d). Speed difference generated between the driven wheels 110 are analyzed being divided into three, that between front and rear wheels, that between right and left wheels on the front side and that between right and left wheels on the rear side. The sum of rotary torques working on the driven wheels 110 is controlled to be always equal to the total load torque which would works on the four wheel driven vehicle during an actual running.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a chassis dynamo for a four-wheel drive vehicle, and particularly to a chassis dynamo that applies a load similar to that in actual driving to each drive wheel of a four-wheel drive vehicle and performs various power measurements. Regarding improvements.

[Prior Art] Chassis dynamometers that measure the power of four-wheel drive vehicles have been well known. It simulates the situation.

Normally, the full load torque T applied to the drive wheels when the vehicle is running is a value α that is the sum of the running resistance torque T based on the speed V and the inertia torque T based on the acceleration α.

For this reason, conventional chassis dynamometers calculate the full load torque T in real time based on the speed and acceleration of the vehicle.
Rotational torque obtained by dividing this full load torque T into four equal parts was applied to each drive wheel.

As shown in Figure 5, the vehicle weight W and WR applied to the front and rear wheels of a four-wheel drive vehicle, especially a full-time 4WD vehicle, are not always constant and vary depending on the vehicle design. There are many cases where it is different.

For this reason, a chassis dynamometer is being developed that can arbitrarily set the ratio of rotational torque applied to the front and rear wheels of a four-wheel drive vehicle.

In other words, the vehicle weight Wp SW applied to the front and rear wheels of a four-wheel drive vehicle
If R is different, the slip limit of the front drive wheels and the slip limit of the rear drive wheels will be different values. For this reason,
In a full-time 4WD vehicle, it is preferable to set the driving force sharing ratio between the front wheels and rear wheels to a value that corresponds to the slip limit.By doing so, in a full-time 4WD vehicle, the driving force of each drive wheel can be maximized. This makes it possible to effectively utilize the vehicle's limited capacity and perform stable driving.

Therefore, a chassis dynamometer that measures the power of a 4WD vehicle uses a sharing ratio setting device to set the sharing ratio between the front drive wheels and rear drive wheels of the test vehicle. It is designed to be able to give rotational torque corresponding to the above-mentioned sharing ratio to the wheels. For example, the driving force sharing ratio between the front drive wheels and the rear drive wheels is each 0.55.0.
45, and assuming that the full load torque is T, 0.55T is applied to the front drive wheels, and 0.5T is applied to the rear drive wheels.
A rotational torque of 45T is applied to simulate actual driving conditions.

Due to the history of the speed difference between the front and rear wheels, proposals have also been made for a chassis dynamo that controls the speed difference between the front and rear wheels of such four-wheel drive vehicles to be equal to that during actual driving. In this case, a predetermined differential speed torque is applied to the front drive wheels and the rear drive wheels so that the differential speed between the front and rear wheels becomes equal to a predetermined set value.

Additionally, in four-wheel drive vehicles where there is almost no difference in speed between the front and rear wheels during actual driving, the speed difference between the front and rear wheels is often controlled to be O when measuring power. .

In this way, the chassis dynamometer for four-wheel drive vehicles calculates the full load torque of the four-wheel drive vehicle during actual driving, and calculates the rotational torque of the vehicle corresponding to the driving force sharing ratio and differential speed between the front and rear wheels. By applying power to the front and rear wheels in real time, we were able to accurately simulate actual driving and perform various power measurements on the chassis dynamo.

[Problems to be solved by the invention (a) However, such a chassis dynamo uses one dynamometer to collectively control the rotational torque of both the left and right front wheels, and the other dynamometer. The rotational torque of the left and right rear wheels is controlled collectively.

Therefore, it is possible to simulate only situations where a speed difference or no speed difference occurs between the left and right wheels of a four-wheel drive vehicle, and tests under conditions where a speed difference occurs between the left and right wheels of a four-wheel drive vehicle, especially the first As shown in FIG. 6, there is a problem in that it is impossible to conduct a power test when a vehicle makes a turning motion with a predetermined turning radius.

(b) Also, in order to solve this problem, what kind of rotational torque should be applied to each drive wheel of a four-wheel drive vehicle? It is also conceivable that fI calculation is performed for each drive wheel, taking into account not only the driving force sharing ratio and the differential speed between the front and rear wheels, but also the differential speed between the left and right wheels.

However, in this case, the calculation processing procedure becomes extremely complicated, making the entire device unavoidably complicated and expensive. Moreover, it is difficult to calculate the rotational torque of each drive wheel in real time. The problem was that it was difficult.

[Object of the Invention] The present invention has been made in view of such conventional problems, and its purpose is to improve the rotational torque applied to each drive wheel of a four-wheel drive vehicle by adjusting the sharing ratio between the front and rear wheels and the differential speed. In addition, the system automatically and in real time calculates and controls the speed difference that occurs between the left and right wheels, accurately simulating actual driving conditions, especially when a four-wheel drive vehicle is turning. The purpose of the present invention is to provide a chassis dynamo for a four-wheel drive vehicle that is capable of being used.

[Means and effects for solving the problems] In order to achieve the above object, the chassis dynamo for a four-wheel drive vehicle of the present invention has the following features:
4 wheels provided in one-to-one correspondence with each drive wheel of a four-wheel drive vehicle.
four dynamometers connected to each of these rollers, and a dynamometer control means that individually controls the output torque of each of the dynamometers and simulates the actual running state of a four-wheel drive vehicle on the rollers; including.

The dynamometer control means includes: a setting device for setting the wheelbase L and king pin pressure M of the four-wheel drive vehicle; a steering angle setting device for manually setting the front wheel steering angle θ of the four-wheel drive vehicle; and a traveling speed. , the wheelbase L, the distance between king pins K, and the front wheel steering angle θ, and based on a predetermined calculation formula, calculate the differential speed ΔV1 between the front wheels and the rear wheels, the differential speed ΔV between the left and right front wheels, and the differential speed between the left and right rear wheels. A differential speed calculation circuit that calculates and outputs ΔV3, a speed detection unit that detects the speed of each drive wheel of the four-wheel drive vehicle, and a four-wheel drive vehicle that calculates the full load torque of the four-wheel drive vehicle based on the traveling speed and acceleration. A full load calculation circuit that calculates the full load sharing torque shared by each of the front and rear drive wheels based on the vehicle's front and rear wheel sharing ratio, and a calculated difference between the front and rear wheels based on the actual speed difference between the front and rear wheels. A front and rear wheel differential speed torque calculation circuit calculates the front wheel side differential speed torque and the rear wheel side differential speed torque that have equal absolute values and differ only in positive and negative signs so as to match the speed ΔV1, and the actual differential speed between the left and right front wheels. A front wheel side differential speed torque calculation circuit calculates and outputs a left front wheel differential speed torque and a right front wheel differential speed torque that have equal absolute values and differ only in positive and negative signs so as to match the calculated differential speed ΔV2, and the actual rear wheel A rear wheel side differential speed that calculates and outputs a left rear wheel differential speed torque and a right rear wheel differential speed torque that have equal absolute values and differ only in positive and negative signs so that the differential speed between the left and right wheels matches the calculated differential speed ΔV3. a torque calculation circuit; a first dynamometer control circuit that controls the output torque of the left front wheel dynamometer based on the front wheel side full load sharing torque, the front wheel side differential speed torque, and the left front wheel differential speed torque; A second dynamometer control circuit that controls the output torque of the front right wheel dynamometer based on the load sharing torque, the front wheel side differential speed torque, and the right front wheel differential speed torque, and the total load sharing torque on the rear wheel side and the rear wheel side differential torque. a third dynamometer control circuit that controls the output torque of the left rear wheel dynamometer based on speed torque and left rear wheel differential speed torque; A fourth controller controls the output torque of the right rear wheel dynamometer based on the wheel differential speed torque.
a dynamometer control circuit;

Then, the vehicle speed of each drive wheel of the four-wheel drive vehicle is automatically controlled so that the sum of the rotational torque given to each drive wheel is always equal to the full load torque, and the four-wheel drive vehicle is driven on the road at the steering angle θ. It is characterized by simulating the state in which the vehicle is turned.

Therefore, according to the present invention, by simply setting the wheel base L, the distance K between the king pins, and the steering angle θ using a setting device in the vehicle, the total sum of rotational torque applied to each drive wheel of a four-wheel drive vehicle can be adjusted. It is controlled to always match the load rotation torque, and in addition to the driving force sharing ratio and differential speed between the front and rear wheels of a four-wheel drive vehicle, the differential speed between both the left and right front wheels and the differential speed between both left and right rear wheels is also controlled at the same time. Since it is possible to apply a rotational torque that is considered to each drive wheel, it is possible to accurately simulate actual road driving and easily perform various power measurements, especially for vehicles where there is a speed difference between the left and right wheels. It becomes possible to perform various power tests by automatically and accurately simulating turning motion.

[Example] Next, preferred embodiments of the present invention will be described based on the drawings.

Embodiment FIG. 2 shows a preferred example of a chassis dynamo for a four-wheel drive vehicle.
b is a pair of rollers 10a.

10b, and the left and right drive transport 100c on the rear wheel side.
, 100d are placed in contact with each other on a pair of rollers 10C110d.

Then, the four-wheel drive vehicle 100 is connected to each roller 10a.

By running on the ... 10d, each roller 10 functions as an infinite flat road instead of an actual road surface.

Therefore, each driving wheel 110a, 110b of the four-wheel drive vehicle 100 is measured using a dynamometer 12a, 12b...12d directly connected to the rotating shaft of each roller 10a, 10b, -10d.
, -110d, it is possible to accurately simulate actual driving and perform various power tests on the four-wheel drive vehicle 100 by applying a rotational torque equal to that in the actual driving state.

In the embodiment, the rotational torque of each driving wheel 110 during actual driving is calculated using the control circuit 14, and each dynamometer 12a is controlled based on the calculated value.

The outputs of 12b, . . . 12d are controlled.

Principle of the Invention Next, the principle of the control circuit 14 will be explained based on FIG.

(a) Full load torque T In FIG. 3(A), each drive wheel 110 of the four-wheel drive vehicle 100
The components of the full load torque applied to a, 110b, and 110d are shown, and as mentioned above, this full load torque T is composed of the running resistance torque T generated corresponding to the vehicle speed, and the vehicle speed. and an inertial torque Ta generated in response to acceleration α.

Therefore, in the device of the present invention, the vehicle speed V and acceleration α
Based on these running resistance torque TV and inertia torque T
is obtained by calculation, and the full load torque T is obtained by adding both α.

By the way, in the coconut dynamo shown in FIG. 2, the roller 0 and the dynamometer body each have a fixed inertia torque TB.

Therefore, each drive wheel 110a of the four-wheel drive vehicle 100.

In order to control the total rotational torque applied to the dynamometers 110b...110d to match the full load torque T, the total output torque TD of each dynamometer 12a, 12b...12d must be set to the value shown by the following formula. It is necessary to control it.

T-T-TB...(1)(
b) Driving force sharing ratio Further, a four-wheel drive vehicle is usually designed so that the driving force between its front wheels and rear wheels is a predetermined sharing ratio of X: (1-X).

Therefore, the device of the present invention, as shown in FIG. 3(B),
The front wheel side full load sharing torque T and the rear wheel side full load sharing torque TR are calculated based on the following equation from the sum=1 output torque To.

T=X-TD...(2
)l koT −(1−x)・T, ・・・(
3)1? Therefore, for example, when the front wheel side sharing ratio is 0.55 and the rear wheel side sharing ratio is 0.45, TF-0.55TD.

The value is TR tone 0.45TD.

(c) Generation of differential speed Also, when a four-wheel drive vehicle performs a predetermined turning movement as shown in FIG. 6, the turning radius 2:
A differential speed occurs between 10a, 110b and 110d.

Therefore, in order to simulate the actual driving conditions of a four-wheel drive vehicle, it is necessary to accurately reproduce the differential speed that occurs between these drive wheels on the chassis dynamometer.

The characteristic features of the present invention are a speed difference ΔV1 that occurs between the front wheels and the rear wheels of a four-wheel drive vehicle, a speed difference ΔV2 that occurs between the left and right wheels on the front wheel side, and a speed difference ΔV2 that occurs between the left and right wheels on the rear wheel side. Differential speed ΔV3
is calculated based on the traveling speed (1) of the four-wheel drive vehicle, the distance between the wheel pressure base 1 and the king pin (HK), and the steering angle θ of the front wheels, thereby controlling the speed of each drive wheel.

(d) Differential speed between front and rear wheels First, in this example, the speed difference ΔV1 generated between the front wheels and rear wheels of a four-wheel drive vehicle is calculated using the following formula based on the constant A1 speed ■ and the steering angle θ. Calculated.

However, R represents the turning radius, and the device of the embodiment calculates the difference speed (V, -VR) between the average speed V of the left and right front wheels of the vehicle and the average speed V of the left and right rear wheels of the vehicle. Measure the front wheel side differential speed torque τ and the rear wheel side differential speed torque - so that this becomes the calculated value ΔV1.
Perform the calculation of F1.

Here, the front wheel side differential speed torque τ1 and the rear wheel side differential speed torque -F1 are determined as values having the same absolute value and different only in their signs.

As shown in FIG. 3(B), the device of the present invention:
The front left and right wheels 110a are based on the following formula.

Shared torque TFl of 110b and both rear left and right wheels 110
Find the shared torque "R1" of c and 110d.

“Pi”””P+τ1...(5
)TI? 1=”R-τl...(
6) Furthermore, divide the above-mentioned "PL'" R□ into two as shown in the following equation, and find the shared torque "F2) for each front wheel" R2).

T+, 2- (T Fl/2)=・(7) T R2
-(TR□/2) ...(8) Therefore, a rotational torque of "F2" is applied to each drive wheel on the front side of a four-wheel drive vehicle, and a rotational torque of TR2 is applied to each drive wheel on the rear side. This makes it possible to accurately simulate the actual driving state of a four-wheel drive vehicle with the driving force sharing ratio x: (1-x) between the front and rear wheels and the differential speed ΔV1.

(e) Differential speed between the left and right wheels Also, as mentioned above, when a four-wheel drive vehicle makes a turning movement,
Depending on the turning radius, the front left and right wheels 110a, 110
A speed difference ΔV2 occurs between
A differential speed ΔV3 also occurs between 10c and 110d.

In particular, the speed difference between the left and right wheels has different values for the front wheels and the rear wheels.

As mentioned above, the characteristics of the present invention are as follows: Using the speed v1 wheelbase L, the distance between king pins K, and the steering angle θ, the difference speed ΔV2 between the left and right front wheels that occurs during actual driving, and the difference between the left and right rear wheels. The purpose is to calculate the differential speed ΔV3 and enable power measurement that accurately simulates the turning motion of a four-wheel drive vehicle.

That is, one of the characteristics of the present invention is to calculate the differential speed ΔV2 between the left and right front wheels using a predetermined calculation formula based on the running speed V1 of the four-wheel drive vehicle, the wheelbase L, the distance between king pins K, and the steering angle θ. Its purpose is to output calculations.

In the embodiment, the differential speed ΔV2 between the left and right front wheels is calculated based on the following equation.

ΔV 2-A X V X K cosθ/R-△x
y x - sin θ...(9) Also,
One of the other characteristics of the present invention is that the differential speed ΔV3 between the left and right wheels on the rear wheel side is ．． The purpose is to calculate and output.

In the embodiment, the differential speed ΔV3 between the left and right rear wheels is calculated based on the following equation.

ΔV 311=IA X V X K / R-A X
V
), and the left front wheel differential speed torque τ2 and the right front wheel differential speed torque −F necessary to detect and control this to the calculated value ΔV2.
Calculate 2.

Here, the values of the left front wheel differential speed torque τ2 and the right front wheel differential speed torque -F2 are determined as absolute values or equal values, and only their σ numbers are different values.

Similarly, the device of the present invention has a differential speed between the left and right wheels on the rear wheel side (
Vc - Vd) is detected, and this differential speed is determined by the calculated value ΔV.
The left rear wheel differential speed torque τ3 and the right rear wheel differential speed torque −τ3 are determined so that the following equations are obtained.

Here, the left and right differential speed torques τ3 and -τ3 are determined as values having the same absolute value and differing only in their signs.

Then, as shown in FIG. 3(C), the device of the present invention determines the left front wheel shared torque Ta and the right front wheel shared torque Tb based on the following equations.

Ta −”rF2+ r2−(tt) Tb−TR2−τ2 (12) Similarly, the device of the present invention determines the left rear wheel shared torque Tc and the right rear wheel shared torque Td based on the following equations.

Tc −TR2+ 73・(13) Td−TR2−τ3 ...(14) And each torque Ta+Tb, Tc obtained in this way
, each dynamometer 12a, 12b based on Td.

By controlling the output torques of the wheels 12c and 12d, a speed difference ΔV2 is generated between the left and right front wheels 110a and 110b, and the left and right rear wheels 110c.

By generating a differential speed ΔV3 between 1 and 10d, the four-wheel drive vehicle 10
0 various power measurements can be performed.

As explained above, according to the present invention, the differential speed generated between each drive wheel of a four-wheel drive vehicle is calculated by converting the differential speed ΔV between the front wheels and the rear wheels into
1, the differential speed ΔV2 that occurs between the left and right front wheels, and the differential speed ΔV3 that occurs between the left and right rear wheels.The differential speed that occurs is systematically analyzed. ing.

Therefore, the rotational torque for generating a predetermined speed difference in each drive wheel can be automatically determined by simple calculation.
It becomes possible to control the differential speed of each drive wheel of a four-wheel drive vehicle in real time using a simple device.

In particular, according to the present invention, based on the traveling speed V of the four-wheel drive vehicle, the distance between the wheelbase L1 king pin, 9K, and the steering angle θ of the front wheels, the speed difference ΔV1 between the front and rear wheels, the speed difference ΔV2 between the left and right front wheels, It is formed to calculate the differential speed ΔV3 between the left and right wheels on the wheel side. This makes the overall device configuration easier.
In addition, it is possible to accurately and simply simulate various turning movements of a four-wheel drive vehicle and measure its power.

Note that the above (4), (9) used in this example,
The formula a in (10) assumes a typical four-wheel drive vehicle and simulates the differential speed that occurs using a predetermined formula based on empirical rules.

In other words, the differential speed ΔV, ΔV2)ΔV3 of each drive wheel that occurs during the turning motion of a four-wheel drive vehicle becomes a complicated calculation equation when calculated geometrically, and many factors are involved in the calculation, so the device The whole thing becomes extremely complex.
' For this reason, in this example, we assume that the four-wheel drive vehicle has its center of gravity near a part of the center, and the differential speeds ΔV1, ΔV2, and ΔV3 that occur in this case are calculated using mathematical formulas determined by empirical rules. I calculated it.

In such a four-wheel drive vehicle, when the steering angles of the front wheels 110a and 110b are set to θ, the front wheel 110a.

110b starts turning at an angle of θ/2, which is about half of that,
At the same time, slip occurs in the rear wheels 110c and 110d, and the center of rotation shifts forward from the position O shown in Fig. 6. Due to this interaction, the four-wheel drive vehicle itself is directed as a whole in the direction of the steering angle θ. You will perform a turning motion using the hand.

In such a case, a speed difference ΔV1 shown by the above equation (4) occurs between the front wheels and the rear wheels of the four-wheel drive vehicle, and a speed difference ΔV1 shown by the above equation (9) occurs between the left and right front wheels. It is determined from experience that a speed difference ΔV2 shown in the equation (10) above occurs, and a speed difference ΔV3 shown in equation (10) above occurs between the left and right rear wheels.

Therefore, according to the device of this embodiment, it is possible to measure the power of a four-wheel drive vehicle whose center of gravity is near the center of the vehicle, and in particular to perform a turning motion test using a simple device with high accuracy. .

Configuration of Control Circuit FIG. 1 shows a preferred example of the control circuit 14. As shown in FIG.

(a) Setting the distance between wheel base L1 king pins, etc. The control circuit 14 of this embodiment is configured by a wheel base setting device 21.
0, kingpin distance setting device 212 and steering angle setting device 2
Contains 14.

Then, the wheelbase setting device 210 is used to set the wheelbase L of the test four-wheel drive vehicle 100, that is, the horizontal distance between the centers of the front and rear axles.

Further, the distance between the king pins of the driving wheels 110 is set using the king pin distance setting device 212.

Further, the steering angle θ of the front drive wheels 110 (a) and 110 (b) of the four-wheel drive vehicle 100 is set using the steering angle setting device 214.

(b) The control circuit 14 of the speed detection embodiment includes a plurality of sensors 20a, 20b, . .

In the embodiment, each of these sensors 20a.

20b and -20d are corresponding rollers 10a.

10b, -10d or dynamometer 12a, 12b, = -12
The speed of the corresponding drive wheel 110 is detected based on the rotational speed of d.

The full-width average speed calculation circuit 22 operates on each sensor 2.
The average value of the detected speeds of 0a, 20b, . . . 20d is calculated and inputted to the full load calculation circuit 28.

Further, the front wheel average speed calculation circuit 24 includes sensors 20a,
The speeds Va and v of both left and right front wheels detected by 20b
The average speed I of b is calculated and manually inputted to the front and rear wheel differential speed torque calculation circuit 30.

Similarly, the rear wheel average speed calculation circuit 26 includes a sensor 20c,
The average speed R of the speeds Vc and Vd of both the left and right rear wheels detected by 20d is calculated, and this is input to the front and rear wheel differential speed torque calculation circuit 30.

(C) Full load torque T In addition, the device of the embodiment uses the sharing ratio setting ratio device 32 to
Front wheel 110a of four-wheel drive vehicle 100.

The driving force sharing ratio X: (1-K) between the rear wheels 110b and the rear wheels 110c and 110d is set, and this is input to the full load calculation circuit 28.

The full load calculation circuit 28 calculates the acceleration α based on the average speed of the four-wheel drive vehicle 100. Then, based on these speeds and accelerations α, the full load torque T shown in FIG. 3(A) is calculated.

(d) Driving force sharing ratio between front and rear wheels Here, inertia torque T that constitutes full load torque T
is composed of a fixed inertia torque TB and an electric inertia torque T. However, the fixed inertia torque TB already exists as a mechanical inertia load of the roller 0 and the dynamometer 12 that constitute the chassis dynamo.

In order to make the sum total of the rotational torque applied to the drive wheels 110a, 110b, ... 110d equal to the full load torque T, the total output torque of each dynamometer 12 must be calculated by combining the electric inertia torque TE and the running resistance torque. It is understood that the control should be performed so that the value TD is the sum of the values TD and TD.

Therefore, the full load calculation circuit 28 of the embodiment calculates the full load torque T based on the average speed and acceleration α, and calculates the value obtained by subtracting the fixed inertia torque TB from the full load torque T to the total of the full dynamometer. Find it as the output torque TD.

Then, based on the sharing ratio x: (1-x), this total output torque T is output from the sharing ratio setting device 32, and the front wheel side full load sharing torque TP-X"T, and the rear wheel side total 1!1f'=
:j shared torque TR-(1-X) TI),
It outputs to each corresponding adder 34-1, 34-2.

(e) Differential speed ΔV1 between the front and rear wheels.
What is the front and rear wheel differential speed calculation circuit 38 that automatically calculates the differential speed ΔV1 between the rear wheels 110a and 110b and the rear wheels 110c and 110d?
It is inputting to 0.

In the present invention, the front and rear wheel speed difference calculation circuit 38 uses a predetermined calculation formula based on the traveling speed V of the four-wheel drive vehicle 100 and the steering angle θ of the front wheels to determine the difference between the front and rear drive wheels. It is formed to calculate and output the speed ΔV1. In this embodiment, the differential speed ΔV1 is calculated and output based on the average speed output from the full width average speed calculation circuit 22 and the steering angle θ output from the steering angle setter 214 using the above equation (4). has been done.

Then, the front and rear wheel differential speed torque calculation circuit 30 calculates and adds the front wheel side differential speed torque τ1 so that the differential speed (VF-Vl,) between the front and rear wheels of the four-wheel drive vehicle 100 matches the set differential speed ΔV1. At the same time, this signal 11 is inverted using an inverter 40 and manually inputted to the adder 34-2 as rear wheel side differential speed torque -τ1.

As a result, the adder 34-1. The front wheel side full load sharing torque "Fl" and the rear wheel side full load sharing torque "R1" are output in consideration of the speed ΔV1.

Then, the output TPi' of each adder 34-1, 34-2
TR1 is further input to the divider 36-1.36-2, where its value is calculated as l/
2, and output as a shared torque TF2 per front wheel side and a shared torque T1.2 per rear wheel side.

(f) Differential speed ΔV2 between left and right wheels. ΔV3 Further, the device of the embodiment calculates the differential speed ΔV2 generated between the left and right front wheels 110a and 110b of the four-wheel drive vehicle 100 using the front wheel side differential speed calculating circuit 40, and calculates the value ΔV2.
is manually input to the front wheel side differential speed torque calculation circuit 42.

In the present invention, the front width side differential speed calculating circuit 40 is configured to calculate and output the differential speed ΔV2 based on the traveling speed of the four-wheel drive vehicle 100, the wheel base L, the distance K between the king pins 2, and the steering angle θ. Specifically, the above-mentioned No. 9
) is formed to calculate and output the differential speed ΔV2 based on the equation.

Further, the device of the embodiment calculates the differential speed ΔV3 between the left and right rear wheels 110c and 110d of the four-wheel drive vehicle 100 using the rear wheel side differential speed calculating circuit 44, and calculates the calculated value ΔV3 on the rear wheel side. It is input to the differential speed torque calculation circuit 46.

In the present invention, the rear wheel side speed difference calculation circuit 44 is configured to calculate and output a speed difference ΔV3 based on the traveling speed of the four-wheel drive vehicle 100, the wheel base L, the distance K between the kingpins 2, and the steering angle θ. Specifically, the above item (10)
It is formed to calculate and output the differential speed ΔV3 based on the formula.

Then, the front wheel differential speed torque calculation circuit 42 determines that the differential speed (VP - ■l?) between the left and right front wheels 110a and 110b detected using the sensors 20a and 20b matches the calculated differential speed ΔV2. Then, the left front wheel differential speed torque τ2 is calculated and inputted to the adder 48a. At the same time,
This differential speed torque τ2 is inverted via the inverter 50 to obtain the right front wheel differential speed torque -τ2, which is manually input to the adder 48b.

Each of the adders 48a and 48b has the
Based on formula 11) and formula (12), both front left and right wheels 11
A left front wheel shared torque Ta and a right front wheel shared torque Tb necessary for generating a speed difference ΔV2 between 0a and 110b are calculated and output.

Similarly, the rear wheel vehicle speed torque calculation circuit 46 calculates the speed of the left and right rear wheels 1 detected using the sensors 20c and 20d.
In order to match the differential speed (Vc - Vd) between 10c and 110d with the calculated differential speed ΔV3, the left rear wheel differential speed torque τ3 is calculated and manually inputted to the adder 48c, and the calculated torque τ3 is
is reversed using the inverter 52 and the right rear wheel differential speed torque -τ
3 is obtained and inputted to the adder 48d.

The adders 48c and 48d each calculate a left rear wheel shared torque Tc and a right rear wheel shared torque T necessary for generating a predetermined speed difference ΔV3 between the left and right rear wheels of the four-wheel drive vehicle 100.
d is calculated and output based on the equations (13) and (14).

(g) Dynamometer output control In this way, each adder 48a, 48b.

48e and 48d are the (11)2 to (14th)
), there is a speed difference Δ between the front and rear wheels of the four-wheel drive vehicle 100.
V1 Front left wheel shared torque Ta, right front wheel shared torque Tb, left rear wheel rotating torque Tc necessary to generate a speed difference ΔV3 between the left and right wheels on the front wheel side)
, calculates and outputs the right rear wheel shared torque Td.

Based on these calculated values, each dynamometer control circuit 5
4a, 54b, . . . 54d control the output torque of the corresponding dynamometers 12a, 12b, . . . 12d.

Therefore, each drive wheel 110a of the four-wheel drive vehicle 100.

110b and -110d are rollers 0a.

10b,...10d, each of these dynamometers 12a
, 12b, . . . , 12d, and the fixed inertia torque inherent to the roller 0 and the dynamometer 12 are applied.

Here, each roller 0a, 10b, .
... Corresponding drive wheels 110a, 110b via 10d
, 110d is the sum total of each fixed inertia torque given to To
, the rollers 10a and 10b.

-10d to each driving wheel 110a, 110b...1
It is understood that the sum of the rotational torques given to 10d is equal to the full load torque T, as expressed by the following equation.

(T a + T b + T c + T d )
+T n-((T +τ)+(T-τ) +
(T,,+F2 2 P2 2 τ )+(T −τ > + T n 1R23 -2T1.2 + 2 T R2+ T B″″T p
+ + T R1+ T B-Tv+Ta+TB ″T p + T R+ T B-TD+TB-T...(15)
With the above configuration, the chassis dynamo for a four-wheel drive vehicle of the present invention can exhibit excellent effects as described below.

(a) First, in the chassis dynamo of the present invention, the front wheels 110a, 110b and the rear wheels 110c, 11 of the four-wheel drive vehicle 100
0d, the sharing ratio x set by the sharing ratio setting device 32: (1
-x) can be applied.

In particular, according to the present invention, as shown in equation (4) above,
Traveling speed of four-wheel drive vehicle 100, front wheels 110a, 110
Considering the steering angle θ of b, the front drive wheels 110a, 11
Differential speed ΔV1 between 0b and rear drive wheels 110c and 110d
In order to automatically control the differential speed so that the actual differential speed (V, -VR) between the front wheels and the rear wheels becomes ΔV1,
It will be appreciated that it is possible to accurately simulate actual driving conditions, particularly when a four-wheel drive vehicle makes a turning movement.

(b) Also, according to the present invention, as shown in Equation (9) above, the front wheels are The differential speed occurring between the left and right wheels 110a and 110b is calculated as ΔV2, and the speed difference between the left and right wheels 110a and 110b is calculated as ΔV2.
Since the actual differential speed (V - V) of b is automatically controlled to the calculated value ΔV2, when the four-wheel drive vehicle is actually driving on the road,
In particular, it becomes possible to more accurately simulate the differential speed between the left and right front wheels, which occurs when the vehicle is turning at a steering angle θ, and to measure its power.

(c) According to the present invention, the traveling speed of the four-wheel drive vehicle 100, the wheel base L
1 Based on the distance K between the king pins and the steering angle θ, the differential speed ΔV3 that occurs between the left and right rear wheels 110C and 110d.
is calculated, and the differential speed (Vo-V, ) between the left and right rear wheels 110C and 110d is controlled to the calculated value ΔV3, completely independently of the front wheels, so the actual road driving conditions can be controlled. It becomes possible to simulate iE more accurately.

(d) Furthermore, according to the present invention, as shown in the above equation (15), 1, each drive wheel 110a, 11 of the four-wheel drive vehicle 100
In order to perform the differential speed control while controlling the total rotational torque applied to 0b...110d to match the full load torque T during actual driving, the speed of the four-wheel drive vehicle 100 under a predetermined load is controlled. Actual driving conditions can be simulated extremely accurately on a chassis dynamometer.

In particular, according to the present invention, if the distance between one king pin and two wheels on the wheel base of the four-wheel drive vehicle 100 is set in advance, the steering angle θ can be input using the steering angle setting device 214 during the power test. The turning motion of various four-wheel drive vehicles can be accurately and automatically simulated on the chassis dynamo simply by simply using the It becomes possible to efficiently perform various power measurements of wheel drive vehicles.

(E) Furthermore, according to the present invention, the differential speed generated between the four drive wheels 110a, 110b, etc. of the four-wheel drive vehicle 100 is reduced to the differential speed ΔV1 generated between the front and rear wheels as described above. , a differential speed ΔV2 occurring between the left and right front wheels, and a differential speed ΔV3 occurring between the left and right rear wheels, which are analyzed and calculated. For this reason, the drive wheel 1
The torque calculation for generating a predetermined speed difference between the wheels 10a, 110b, .

Therefore, according to the present invention, the configuration of the entire device can be made simple and inexpensive, and the actual driving state of the four-wheel drive vehicle 100 can be accurately simulated in real time to perform various power measurements.

(f) Furthermore, according to the present invention, as described above, the wheelbase L and king pin pressure # of the four-wheel drive vehicle 100 may be set in advance, and then the steering angle θ of the front wheels may be input. , the operator can easily set each data, and even when such differential speed control is performed automatically using an electronic computer, the program for the swing motion test can be extremely simple. It becomes possible to make it a thing.

Specific Embodiment FIG. 4 shows a specific circuit configuration of the block diagram shown in FIG. 1.

In embodiments, each sensor 20 includes a pickup 20-
1 is used to detect the rotation speed of the corresponding roller 10, and the detected rotation speed is converted to a running speed using a detector 20-2 and output.

Further, the sharing setting device 32 of the embodiment includes a setting device 32a that sets the front wheel sharing ratio X, and a calculator 32b that calculates and outputs the rear wheel sharing ratio (1-x) based on this set value, Each of these sharing ratios is input to the full load calculation circuit 28.

Further, this full load calculation circuit 28 includes a running resistance calculation section 60.
and an inertia resistance calculating section 62, which calculates the running resistance torque Tv based on the vehicle running speed and the inertia torque Tα based on the acceleration α.

That is, the running resistance calculating section 60 includes a load setting device 64 and a pair of integrator 66, 68.

The load load setting device 64 calculates and outputs the running resistance torque Tv at the average speed output from the full width average speed calculation circuit 22.

As such a load setting device 64, devices employing various methods are well known, and in this embodiment, the relationship between the vehicle speed V and the running resistance torque is set in advance, and the torque corresponding to the speed is formed so as to output as running resistance torque Tv.

One of the integrator 66 calculates the running resistance torque T of the entire four-wheel drive vehicle output from this load setting device 64.
v is multiplied by the sharing ratio X of the front drive wheels, and the front drive wheels 11
Running resistance sharing torque (xTv) applied to 0a and 110b
is calculated and output.

Further, the other integrator 68 calculates the driving force sharing ratio of the rear drive wheels 110c and 110d (
1-x), these rear drive wheels 110c,
Running resistance sharing torque (1-x)Tv applied to 110d
Calculate and output.

The inertial resistance calculation unit 62 also includes a vehicle mW setter 70 that sets the vehicle weight W of the four-wheel drive vehicle 100, and includes a vehicle mW setter 70 that sets a set value W.
is input to integrator 74 and 76.

The integrator 74 integrates the vehicle weight W and the front wheel side sharing ratio X,
The inertia load WX of the front drive wheels 110a and 110b is calculated and input to the subtracter 78.

Similarly, the other integrator 76 integrates the vehicle weight W and the rear wheel side sharing ratio (1-x), and calculates the same rear wheel drive width 110c,
The inertial load W(1-x) shared by 110d is calculated and input to the subtracter 80.

The inertial resistance calculation unit 62 also includes a setting device 82 for setting the fixed inertial load Wr3F of the front wheel roller and the dynamometer.
It includes a setter 84 for setting the fixed inertia W n RG of the rear wheel side roller and the dynamometer, and these set values are manually input to the corresponding subtractors 78 and 80 .

Then, one subtracter 78 subtracts the fixed inertial load WBP from the inertial load WX on the front wheel side, and the subtracted value (W x
Wnp) is the electric inertia load WEF on the front wheel side, and the integrator 8
4 direction is output.

Similarly, the other subtracter 80 subtracts the output of the setter 84 from the output of the previous stage integrator 76, and the subtracted value 1W (1
-X)-WB,) is outputted to the integrator 88 as the electrical inertia negative 41 W□ on the rear wheel side.

The inertial resistance calculation section 62 detects the acceleration α using the acceleration sensor 72 in order to calculate the electrical inertia load thus obtained into an electric inertia torque corresponding to the acceleration α.

In the embodiment, the acceleration sensor 72 calculates and outputs the acceleration α by differentiating the vehicle 81 and the uniform velocity.

Then, each integrator 84 and 88 calculates the electric inertia shared torque TCP on the front wheel side and the electric inertia shared torque TER on the rear wheel side based on the following equation, and adds these to the corresponding addition'! The signals are input to five devices 90 and 92, respectively.

TEF-α・WEF-xTE...(16) TEL-
cx -WER-(1-x) TE-(17) and
One adder 9o adds the running resistance shared torque and electric inertia shared torque of the front wheels output from the integrators 66 and 86 as shown in the following formula, and converts the added value into the total load shared torque of the front drive wheels. Output as TF.

TF-x Tv +x TE-X ・(Tv +TE)
(18) Similarly, the other adder 92 includes integrators 68 and 8.
The running resistance sharing torque and electric inertia sharing torque of the rear drive wheels outputted by No. 8 are added as shown in the following formula, and the added value TR is output as the full load sharing torque TR of the rear drive wheels 110c and 110d. .

TR=(1-x) TV +(1-X) TE-(1-
x) (T v + T E) ... (1
9) Furthermore, the front and rear wheel differential speed calculation circuit 38 of this embodiment uses the steering angle θ output from the setting device 214 and the speed output from the full width average speed calculation circuit 22 to calculate the equation (4) above. Based on this, the differential speed ΔV1 between the front and rear wheels is calculated and output.

The front and rear wheel differential speed torque calculation circuit 30 of the embodiment includes a subtractor 30a that detects the differential speed between the average speed V of the left and right front wheels and the average speed VR of the left and right rear wheels, and The differential speed torque τ1 is calculated and outputted using a torque calculator 30c so that the detected deviation becomes zero.

Further, the front wheel side differential speed calculation circuit 40 of the embodiment is used for the four-wheel drive vehicle 1.
Based on the traveling speed of 00, the wheel base L, the distance between the king pins K, and the steering angle θ of the front wheels, the differential speed ΔV2 between the left and right front wheels is calculated and output using the equation (9).

The front wheel differential speed torque calculation circuit 42 includes a subtracter 42
a, 42b and a calculated torque value 42c, and the differential speed torque τ2 of the left front wheel 110, a is set so that the deviation between the differential speed (Va - Vb) between the front left and right wheels and the calculated differential speed ΔV2 becomes 0.
is calculated and output.

Further, the rear wheel side differential speed calculation circuit 44 of the embodiment uses the traveling speed of the four-wheel drive vehicle, the wheel base L, the distance between king pins K, and the steering angle θ, and calculates the speed difference between the left and right rear wheels based on the above-mentioned equation (10). The differential speed ΔV3 is calculated and output.

The rear wheel differential speed torque calculation circuit 46 includes a subtracter 46
a, 46b, and a torque calculator 46c, and calculates and outputs the differential speed torque τ3 of the left rear wheel so that the deviation between the differential speed (Vc - Vd) of both left and right rear wheels and the calculated differential speed ΔV3 becomes 0. ing.

The dynamometer control circuit 54 of the embodiment also includes a load cell 54-1 that detects the rocking torque of the corresponding dynamometer 12 and outputs it via the amplifier 54-2, and a rocking torque and the output of the adder 48. The torque control circuit 54-4 includes a gate pulse generator 54-5 and a thyrisk unit 5 so that the verification values match.
4-6 controls the output of the dynamometer 12.

[Effects of the Invention] As explained above, according to the present invention, the differential speed occurring between each drive wheel of a four-wheel drive vehicle is divided into the differential speed occurring between the front and rear wheels and the left and right wheels on the front wheel side. The differential speed that occurs is divided into three elements: the differential speed that occurs between the wheels, and the differential speed that occurs between the left and right rear wheels, and the differential speed that occurs is systematically analyzed. Therefore, when a four-wheel drive vehicle is actually running with a predetermined speed difference between each drive wheel, the rotational torque applied to each drive wheel can be calculated easily and quickly. The differential speed control of each drive wheel of a car can be performed automatically and in real time using a simple device.

Further, according to the present invention, since the sum of the rotational torques applied to each of these driving wheels is controlled to always be equal to the total load torque applied to the four-wheel drive vehicle during actual driving, the four-wheel drive It becomes possible to accurately simulate and measure the power of various power tests on wheel drive vehicles, especially when a four-wheel drive vehicle is turning under predetermined torque conditions.

In particular, according to the present invention, if the wheelbase and distance between the king pins of the four-wheel drive vehicle are set in advance, the steering angle θ of the four-wheel drive vehicle can be inputted during the power test, and the four-wheel drive vehicle can be It is possible to automatically calculate and control the differential speed between the front and rear wheels, the differential speed between the left and right front wheels, and the differential speed between the left and right rear wheels.

Therefore, it is possible to accurately reproduce the same situation when a four-wheel drive vehicle turns the steering wheel on the road on a chassis dynamometer with simple operations, and to perform various vehicle turning performance tests.

Furthermore, according to the present invention, by simply setting the wheelbase of the test vehicle and the distance between the king pins in advance, it is only necessary to perform a simple operation such as setting the steering angle θ as necessary during the test. Therefore, the burden on the operator can be significantly reduced.

[Brief explanation of the drawing]

1 and 2 are block diagrams showing a preferred embodiment of a chassis dynamo for a four-wheel drive vehicle according to the present invention, FIG. 3 is an explanatory diagram showing the principle of the present invention, and FIG. 4 is a diagram similar to that shown in FIG. Figure 5 is an illustration of the vehicle weight applied to the front and rear wheels of a four-wheel drive vehicle, and Figure 6 is an illustration of the specific circuit configuration of the block diagram shown in Figure 6. FIG. 10a, 10b, 10c, 10d-o-ra 12a, 12
b, 12c, 12d--Dynamometer 14...Control circuit 20a, 20b, 20c, '20d--Speed sensor 22...All-wheel average speed calculation circuit 24...Front wheel average speed calculation circuit 26- ... Rear wheel average speed calculation circuit 28 ... Full load calculation circuit 32 ... Front and rear wheel differential speed torque calculation circuit 38 ...
Front and rear wheel speed differential calculation circuit 40... Front wheel side differential speed calculation circuit 42... Front wheel side differential speed torque calculation circuit 44...
Rear wheel side differential speed calculation circuit 46... Rear wheel side differential speed torque calculation circuit 50a,
50b, 50c, 50d... Dynamometer control circuit

Claims (5)

[Claims] (1) Four rollers provided in one-to-one correspondence with each drive wheel of a four-wheel drive vehicle, four dynamometers connected to each of these rollers, and output torque of each of the dynamometers. dynamometer control means for individually controlling and simulating the actual running state of the four-wheel drive vehicle on the rollers, the dynamometer control means for setting the wheel base L and the distance between the king pins of the four-wheel drive vehicle; a steering angle setting device for inputting the front wheel steering angle θ of the four-wheel drive vehicle, a speed detection section for detecting the speed of each drive wheel of the four-wheel drive vehicle, and a steering angle setting device for inputting the front wheel steering angle θ of the four-wheel drive vehicle; and a front wheel steering angle θ, a speed difference calculation circuit that calculates and outputs a speed difference ΔV_1 between the front wheels and the rear wheels, a speed difference ΔV_2 between the left and right front wheels, and a speed difference ΔV_3 between the left and right rear wheels based on a predetermined calculation formula. Then, calculates the full load torque of the four-wheel drive vehicle based on the traveling speed and acceleration, and calculates the full load shared torque shared by each of the front and rear drive wheels based on the front and rear wheel sharing ratio of the four-wheel drive vehicle. The full load calculation circuit calculates front wheel side differential speed torque and rear wheel side differential speed torque that have the same absolute value and differ only in positive and negative signs so that the actual differential speed between the front and rear wheels matches the calculated differential speed ΔV_1. The front and rear wheel differential speed torque calculation circuit, and the differential speed ΔV_2 that calculates the actual differential speed between the left and right front wheels.
A front wheel side differential speed torque calculation circuit calculates and outputs a left front wheel differential speed torque and a right front wheel differential speed torque that have equal absolute values and differ only in positive and negative signs, and a a rear wheel side differential speed torque calculation circuit that calculates and outputs a left rear wheel differential speed torque and a right rear wheel differential speed torque that have equal absolute values and differ only in positive and negative signs so as to match the calculated differential speed ΔV_3; and a front wheel side a first dynamometer control circuit that controls the output torque of the front left wheel dynamometer based on the full load sharing torque, the front wheel side differential speed torque, and the left front wheel differential speed torque; a second dynamometer control circuit that controls the output torque of the right front wheel dynamometer based on the speed torque and the right front wheel differential speed torque, and the rear wheel side full load sharing torque, the rear wheel side differential speed torque, and the left rear wheel differential torque. a third dynamometer control circuit that controls the output torque of the left rear wheel dynamometer based on the rear left wheel speed torque; The fourth controller controls the output torque of the rear wheel side dynamometer.
The dynamometer control circuit controls the vehicle speed of each drive wheel of the four-wheel drive vehicle so that the sum of rotational torque applied to each drive wheel is always equal to the full load torque, and the four-wheel drive vehicle A chassis dynamo for four-wheel drive vehicles that is characterized by simulating driving conditions on the road at a steering angle θ. (2) In the device according to claim (1), the speed difference calculation circuit calculates a speed difference ΔV_1 between the front wheels and the rear wheels according to a predetermined calculation formula based on the traveling speed of the four-wheel drive vehicle and the front wheel steering angle θ. a front wheel side differential speed calculation circuit that calculates and outputs a front wheel differential speed calculation circuit, and a front wheel side differential speed calculation circuit that calculates a differential speed difference ΔV_2 between the left and right front wheels according to a predetermined calculation formula based on the traveling speed, wheel base L, distance K between king pins, and steering angle θ. a calculation circuit; and a rear wheel side differential speed calculation circuit that calculates a differential speed ΔV_3 between the left and right rear wheels according to a predetermined calculation formula based on the traveling speed, wheel base L, distance between king pins, and steering angle θ. A chassis dynamo for four-wheel drive vehicles. (3) In the device according to any one of claims (1) and (2), the front and rear wheel speed difference calculation circuit calculates the speed difference between the front and rear wheels based on the following equation using a constant A, a front wheel steering angle θ, and a running speed V. A chassis dynamo for a four-wheel drive vehicle characterized by calculating and outputting a wheel speed difference ΔV_1. ΔV_1A×V×[(L/cosθ)-1] (4) In the device according to any one of claims (1) to (3), the front wheel side differential speed calculation circuit comprises a constant A, a traveling speed V, a wheel base L, a distance between king pins K, and a front wheel steering angle. A chassis dynamo for a four-wheel drive vehicle, characterized in that it calculates and outputs a differential speed ΔV_2 between left and right front wheels based on the following equation using θ. ΔV_2=A×V×(K/L) sinθ (5) In the device according to any one of claims (1) to (4), the rear wheel side differential speed calculation circuit comprises a constant A, a traveling speed V, a wheel base L, a distance between king pins K, and a steering angle. Using θ,
A chassis dynamo for a four-wheel drive vehicle, characterized in that it calculates and outputs a differential speed ΔV_3 between left and right rear wheels based on the following equation. ΔV_3=A×V×(K/L)tanθ