JPH02269934A - Reproducing device for slip state for vehicle test - Google Patents

Abstract

PURPOSE:To easily and accurately reproduce the slip state of the vehicle corresponding to a road surface state by reproducing the slip state of the vehicle with the engagement state of an electromagnetic clutch. CONSTITUTION:When both a wheel M2 and a flywheel M3 rotate, a slip state generating device M4 applies a braking force or driving force to the wheel M2 to generate a slip state between the wheel M2 and flywheel M3. Then the flywheel M3 corresponds to the actual inertial force of the vehicle and the engagement state of the electromagnetic clutch M1 corresponds to the road state which is set as a test condition. For the purpose, the relation between the slip rate of the wheel M2 and flywheel M3 and the engagement state of the electromagnetic clutch M1 is matched with the relation the slip rate of a driving wheel in the actual slip state of the vehicle stored in a storage means M6 and transmission torque from a driving system to a road surface to reproduce the actual slip state of the vehicle in the road state set as the test condition.

Description

[Detailed Description of the Invention] 1. Field of Industrial Application The present invention relates to a slip state reproduction device for vehicle testing that reproduces the slip state during acceleration or braking of a vehicle under a set road surface condition. .

[Prior Art] Various test reproduction devices have been proposed to evaluate vehicle acceleration, braking, etc. performance, and a brake test device that compares flywheel inertia to vehicle weight is well known. (For example, Japanese Patent Application Laid-open No. 162025/1983).

Recently, there has been progress in the development of devices that use electronic control to adjust the braking force to suppress the occurrence of slippage during vehicle braking or acceleration.In order to evaluate the performance of this electronic control device, we A device has been proposed for reproducing the slip condition of a vehicle depending on the condition.

As a conventional vehicle slip state reproducing device (as shown in Table 7), a motor d is connected to the wheel a of the wheel a via an electromagnetic clutch C, and a motor d is connected to the surface of the wheel a to drive the wheel a.
There is one equipped with a flywheel e that rotates together with the flywheel e, and a hydraulic cylinder f that presses the wheel a against the flywheel e. The hydraulic cylinder f applies a pressing force to the wheel a via a slide bearing g fitted on the outside of the wheel, and the hydraulic pressure is maintained at a constant level by a pressure reducing valve. Since it changes depending on the road surface condition, the evaluation of devices that control slip conditions, such as anti-skid control devices that prevent the wheels from locking even if sudden braking is applied on a slippery road surface such as a snowy road, is based on the actual road surface. It is necessary to do this depending on the situation. In the conventional device shown in FIG. 7, the friction coefficient μ of the road surface is adjusted by applying soapy water to the contact area between the wheel a and the flywheel e, and the pressing force by the hydraulic cylinder f (i.e. Transmission torque F= between wheel a and flywheel e by adjusting the ground load N) in the actual vehicle
By adjusting μ・N, various road surface conditions are reproduced.

[Problem to be solved by the invention 1 However, as mentioned above, the friction coefficient μ of the contact surface between the wheel a and the flywheel e is used as a parameter for reproducing the road surface condition.
It is difficult to adjust accurately. Specifically, wheel a
Since the surface of wheel a wears out with use, the coefficient of friction μa of wheel a itself is not constant over time, and the problem is that it is not possible to accurately reproduce the coefficient of friction μ of the road surface even if the amount and type of soapy water applied are the same. As a result, the reproducibility of the slip condition of the vehicle depending on the road surface condition was poor.In addition, for the above reasons, each time during the test, the actual transmission torque F between the wheel a and the flywheel e was determined in advance. There is a problem in that the pressing force N by the hydraulic cylinder f has to be finely adjusted each time based on the result, and the workability is poor. The object of the present invention is to solve such problems and easily and accurately reproduce the slip condition of a vehicle depending on the road surface condition.

[Means for solving the problem] The slip state reproduction device for vehicle testing of the present invention (which reproduces the slip state that occurs on the drive shaft of the vehicle in response to the road surface condition when the vehicle is accelerating or braking) A slip state reproduction device for experimentally reproducing a vehicle test, which applies braking force or driving force to a vehicle M2 and a flywheel M3 whose rotating shafts are connected to each other via an electromagnetic clutch M1, and to the wheel M2. slip state generating means M4 for generating a slip state between the wheel M2 and the flywheel M3; and the slip state generating means M4 for generating a slip state between the wheel M2 and the flywheel M3. a slip rate calculating means M5 for calculating a slip rate between the wheel M2 and the flywheel M3 based on the rotational speed of the wheel M2 and the flywheel M3 after
and a storage means M6 that stores the relationship between the slip ratio of the drive shaft and the torque transmitted from the drive system to the road surface in an actual vehicle with respect to the road surface condition set as the test condition, and with reference to the storage means M6. , the slip rate calculation means M
5, the torque transmitted from the drive system to the road surface determined in accordance with the slip ratio calculated in step 5 is set as a target value of torque to be transmitted between the wheels M2 and the flywheel M3 by the electromagnetic clutch M1. Torque target value setting means M7 and the electromagnetic clutch M according to the set transmission torque target value based on the characteristics of the electromagnetic clutch M1.
The present invention is characterized in that it includes an electromagnetic clutch control means M8 that controls the engagement state of the first clutch.

[Function] In the slip state reproduction device for vehicle testing having the above configuration, when both the wheel M2 and the flywheel M3 are rotating, the slip state generating device M4 reproduces the slip state of the wheel M2.
By applying braking force or driving force to the wheel M2
A slip condition is generated between the flywheel M3 and the flywheel M3. (Table) When the vehicle @ M2 and the flywheel M3 are stopped, the slip state generating means M4 applies a driving force to the wheel M2, thereby generating a slip state between the wheel M2 and the flywheel M3. let

When a slip condition occurs, the slip rate calculating means M5 calculates the slip rate between the wheels M2 and the flywheel M3 based on the rotational speed of the wheels M2 and flywheel M3. When the slip ratio is calculated, the transmission torque target value setting means M7 refers to the storage means M6 and sets the transmission torque from the drive system to the road surface corresponding to this slip ratio to the wheels M2 and the flywheel using the electromagnetic clutch M]. This is set as the target value of the torque to be transmitted between M3 and M3. According to the transmission torque target value thus set, the electromagnetic clutch control means M8 controls the engagement state of the electromagnetic clutch M1 according to its characteristics.

In the device of the present invention, the flywheel M3 corresponds to the inertia force of the actual vehicle, and the engagement state of the electromagnetic clutch M1 corresponds to the road surface state set as the test condition. Therefore, the relationship between the slip rate between the wheel M2 and the flywheel M3 and the engagement state of the electromagnetic clutch M1 can be determined from the slip rate of the driving wheels and the drive system in the actual vehicle slip condition stored in the storage means M6. By matching the relationship with the torque transmitted to the road surface, it is possible to reproduce the actual slip state of the vehicle in the road surface state set as the test condition.

[Example 1] Next, as an example of the slip condition reproducing device for vehicle testing of the present invention, a device configured as a device for testing the control performance of an anti-skid control device for a vehicle will be described. Figure 2 shows the system configuration diagram.

As shown in FIG. 2, the device of the embodiment (Table: wheel 1, flywheel 3, powder clutch 9 that connects the rotating shafts of both (wheel 5 and flywheel shaft 7), and electromagnetic clutch)] A motor that provides rotational force to the wheels 5 ] 3
and a wheel rotation speed sensor that detects the rotation speed of the wheel 5]
5, a flywheel rotational speed sensor that detects the rotational speed of the flywheel shaft 7] 7, and an electronic control device 20 that receives the detection values of the sensors 15 and 17 and adjusts the engagement state of the powder clutch 9. , and a brake 30 that applies braking to the wheels 1.

On the other hand, an anti-skid control device 40 whose performance is tested by this device is installed so as to receive the detection values of the rotational speed sensors 15 and 17 and adjust the braking force of the brake 30.

Also, the electronic control unit 20f is a well-known CPU2+.

ROM23. RAM25. It includes an input/output section 27 and a common bus 29 that interconnects these sections, and is configured as a logic operation circuit.

In the ROM 23 (above) A package of processing programs. When the vehicle is actually slipping, the value of the torque to be transmitted from the vehicle's drive system to the road surface in various road surface conditions with respect to the slip rate of the vehicle's drive wheels is stored in advance. What is determined is stored in memory.Specifically, a curve representing the relationship between slip ratio and transmitted torque for each road surface condition can be referenced in the form of a function or a map, as shown in Figure 3. There is.

In addition, the input/output section 27 (air) is in charge of transmitting and receiving signals between the inside of the electronic control device 20 and external measuring devices, etc., and is used to set road surface conditions etc. as conditions for performance testing of the anti-skid control device 40. When the signal from the keyboard 50 is received, the +L signal is sent to the XY plotter 60 during the test.
The slip rate occurring between the flywheel 3 and the flywheel 3 is sent out moment by moment.

Here, to explain a little about Fig. 3, the horizontal axis of the figure represents the slip ratio SR, and the vertical axis represents the torque Tt transmitted between the drive shaft and the road surface in an actual vehicle. There is. Further, the curve T corresponds to a dry state of the asphalt road surface, the curve 2 corresponds to a wet state of the asphalt road surface, and the curve 2 corresponds to an ice burn.

Next, the slip state reproduction process executed by the electronic control device 20 in the performance test of the anti-skid control device 40 is as follows.
This will be explained based on the flowchart shown in FIG. The anti-skid control device 40 operates independently of the main body of the slip state reproduction device, and controls the hydraulic pressure of the brake 30 to set the slip ratio SR between the wheels 1 and the flywheel 3 to a predetermined value (in this embodiment). 20%).

At the start of the test, settings such as vehicle speed and road surface conditions are made as test conditions to be reproduced (step 100).

Next, the electromagnetic clutch 11 is connected and the motor 13 is driven to adjust the rotational speed NO of the wheel 1 to the set vehicle speed condition while referring to the detected value of the wheel rotational speed sensor 15, and then the electromagnetic clutch is connected. 11 and stop the motor 13 (step]]0).

Once the initial conditions are set as described above, the performance test of the anti-skid control device 40, which is the purpose of the test, is finally started. This test will be described later based on the flowchart in Figure 5 above.

Electronic control device 2017: Performs control independently of anti-skid control, and first reads wheel rotation speed N+ and flywheel rotation speed N2 detected by wheel rotation speed sensor 15 and flywheel rotation speed sensor 17 (
Step 120). Based on this read value, the slip ratio SR between the wheel 5 and the flywheel shaft 7 = (N2
-Nl )/N2 is calculated (step 130).

Subsequently, referring to the function stored in the ROM 23, step] 40) calculates the transmission torque target value RTt to be reproduced between the wheel 5 and the flywheel shaft 7 based on the slip ratio SR (step 150). . Specifically, as shown in Fig. 3, for example, when a wet asphalt road surface is selected as the road surface condition, the value Ttl on the vertical axis of the curve ■ corresponding to the calculated slip ratio SRI is read. , this is the transmission torque target value RTt
shall be.

Based on the transmission torque target value RTt thus calculated, the current applied to the powder clutch 9 is adjusted to adjust its engagement state (step 160). The relationship between the current applied to the powder clutch 9 and the engagement state (transmitted torque between the wheels 5 and the flywheel shaft 7) is uniquely determined, and this is also stored in the ROM 23 as a function or map. has been done.

Thereafter, it is determined whether or not the test termination condition is met based on conditions such as the vehicle speed being zero or a predetermined time elapsed (step 170), and the processes from step 120 onward are repeated until the test is terminated.

Note that the processes in steps 120 to 170 have a practical meaning after a slip condition occurs between the wheel and the flywheel 3, and before that, the processes in steps 120 to 170 are performed without changing the engagement state of the powder clutch 9. It's just repeating the loop.

If the start button 45 of the anti-skid control device 40 is pressed at this point (step 110 and below), the brake 3
0 operates to suppress the rotational speed of the wheels, and a slip condition occurs between the wheels 1 and the flywheel 3.

Next, the processing executed by the anti-skid control device 40 will be explained.

First, after wheel 1 reaches the rotational speed NO, which is the test condition (
In step 110), when the start button 45 of the anti-skid control device 40 is pressed, the process of the flowchart in FIG. 5 is started. Anti-skid control device 40 (table
A hydraulic cylinder (not shown) of the brake 30 is driven with a predetermined oil pressure to apply a predetermined braking force to the wheel 1 (step 200).

The magnitude of the braking force applied here is set as an initial condition. For example, if you are testing anti-skid control performance during sudden braking, the hydraulic pressure corresponding to the maximum braking force should be applied to the hydraulic cylinder of brake 3o. It will be done.

Next, read the wheel rotation speed N1 (step 210
), this wheel rotational speed N1 is compared with the maximum vehicle body deceleration estimated from the initial wheel deceleration, and the slip ratio SRe is calculated (step 220).

It is determined whether the calculated slip ratio SR is 20%, which is the target value for anti-skid control, and 5R=2.
If it is 0%, maintain the braking force as it is (Step 240)
, if SR>20%, reduce the braking force (step 25
0), if SR<20%, increase the braking force (step 260).Until the test termination condition is met, repeat the process from step 210 onwards to increase the slip ratio SR to 20%.
Execute control to maintain in %.

As described above, the test device reproduces a predetermined road surface condition by the slip condition reproduction control, and the anti-skid control device 40 independently executes one anti-skid control. Here, regarding the responsiveness and accuracy of anti-skid control, the XY plotter 60 connected to the electronic control device 20
The determination can be easily made by storing the change in the slip ratio SR over time.

As explained above, in this embodiment, a configuration is adopted in which the slip condition of the vehicle is reproduced by the engaged state of the powder clutch 9. Therefore, by adjusting the electric signal instructing the engaged state of the powder clutch 9, Vehicle slip conditions can be uniquely and directly reproduced.

Further, the engagement state of the powder clutch 9 is adjusted by referring to the relationship between the slip ratio SR of the drive wheels of the actual vehicle for each road surface condition stored in the ROM 23 and the torque Tt transmitted from the drive system to the road surface. By adopting this method, it is possible to reproduce a slip state in which the slip rate of the vehicle changes sequentially, such as when reproducing the braking of a vehicle, by accurately corresponding to the road surface condition.

Furthermore, even when changing the braking force of the brake 30 during braking, such as anti-skid control, it can be handled independently of the brake operation.

As a result, according to the device of this embodiment, it is possible to easily and accurately reproduce the slip condition of the vehicle for each road surface condition. Because it relies solely on Therefore, there is no need to check the reproducibility of the slip condition in advance, and the workability of the test is improved.As a result, in the performance test of a device that controls the slip condition itself, such as the anti-skid control device 40, such a device is used. The performance of the anti-skid control device 40 can now be judged accurately and easily.In addition, since the road surface condition is reproduced independently of the anti-skid control, the performance of the anti-skid control device 40 can be judged based on the slip over time of the xY plotter. It is only necessary to look at the change in the rate SR, and an extremely easy and accurate determination can be made.

In this embodiment, the performance test of the amplifier skid control device 40 was explained as an example, but it can also be used to test the traction performance as shown in FIG.

In this case, the first test condition is the road surface condition.

The initial speed (zero if starting), acceleration force, etc. are set (step 300), and the motor 13 is activated according to this acceleration force.
is driven to rapidly accelerate the wheel 1 side to generate acceleration slip between the wheel 1 and the flywheel 3 (step 31).
0). Thereafter, the slip ratio SR is determined from the rotational speeds of the wheels 1 and the flywheel 3 in the same way as in the anti-skid control described above, and the transmission torque target value RTt obtained by referring to the ROM 23 based on this value is determined. The engagement state of the powder clutch 9 is controlled so that (steps 320 to 37
0).

In this way, the device of this embodiment not only tests anti-skid control performance by applying braking force to the wheel 1 side, but also tests traction control performance by rapidly accelerating the wheel 1 side. can also be provided.

Such effects (such as wheel 1
This is because the torque transmitted from the drive system of the actual vehicle to the road surface is reflected in the engagement state of the powder clutch 9 using the slip ratio between the flywheel 3 and the flywheel 3 as a parameter.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments. For example, a hysteresis clutch or the like may be used in place of the powder clutch 9. It can be implemented in various ways within the scope.

As described in detail, the slip state reproducing device for vehicle testing of the present invention adopts a configuration that reproduces the slip state of the vehicle from the engagement state of the electromagnetic clutch. and can be directly reproduced.

In addition, a configuration is adopted in which the engagement state of the electromagnetic clutch is adjusted by referring to the relationship between the slip ratio of the drive shaft of the actual vehicle for each road surface condition stored in the storage means and the torque transmitted from the drive system to the road surface. Therefore, slip conditions in which the slip rate of the vehicle changes sequentially, such as when reproducing vehicle braking or sudden acceleration, can be reproduced in accurate correspondence with road surface conditions.

As a result, the device of the present invention can be used as a +? The slip state of a vehicle for each road surface condition can be easily and accurately reproduced.

In addition, since this reproduced road surface condition depends only on the engagement state of the electromagnetic clutch, it does not include any uncertain factors and is extremely reliable. Therefore, there is no need to check the reproducibility of the slip condition in advance, and the workability of the test has also improved.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram illustrating the configuration of the present invention. FIG. 2 is a system configuration diagram of an embodiment of the present invention. FIG. 3 is a ROM 23.
FIG. 4 is a graph illustrating the relationship between the slip ratio and the transmitted torque for each road surface condition stored in the electronic control unit 20.
FIG. 5 is a flow chart of the anti-skid control process executed in the anti-skid control device 40, and FIG. 6 is a flow chart of the process to reproduce an accelerated slip condition in the device of the embodiment. , FIG. 7 is a configuration diagram of a conventional slip condition reproduction device for vehicle testing. Ml...Electromagnetic clutch M2-...Wheel M3...Flywheel M4...Slip state generating means M5...Slip rate calculation means M6...Storage means Ml...Transmission torque target value setting means M8 ... Electromagnetic clutch control means] ... Car @ 3 ... Flywheel 9 ... Powder clutch 11 ... Electromagnetic clutch 13 ... Motor
]5...Wheel rotation speed sensor]7...Flywheel rotation speed sensor 20...Electronic control device 23...
ROM30...Brake 40...Anti-skid control device

Claims (1)

[Scope of Claims] A slip state reproduction device for vehicle testing that experimentally reproduces the slip state that occurs in the drive wheels of a vehicle in response to road surface conditions when the vehicle is accelerating or braking, the device comprising: an electromagnetic clutch; a wheel and a flywheel whose rotating shafts are connected to each other; a slip state generating means that applies braking force or driving force to the wheel to generate a slip state between the wheel and the flywheel; and the slip state. a slip ratio calculating means for calculating a slip ratio between the wheel and the flywheel based on the rotational speed of the wheel and the flywheel after the generating means generates a slip state between the wheel and the flywheel; and as test conditions. a storage means that stores the relationship between the slip ratio of the drive wheels and the torque transmitted from the drive system to the road surface in an actual vehicle with respect to a set road surface condition; Transmission torque target value setting means for setting a transmission torque from the drive system to the road surface determined in accordance with the calculated slip ratio as a target value of the torque to be transmitted between the wheels and the flywheel by the electromagnetic clutch; , an electromagnetic clutch control means for controlling the engagement state of the electromagnetic clutch according to the set transmission torque target value based on the characteristics of the electromagnetic clutch.