JP2833320B2 - ABS test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test apparatus for an antilock brake system (hereinafter referred to as "ABS") capable of preventing tire slippage caused by locking of a wheel during braking, and more particularly to a smooth braking operation on the test road. The present invention relates to an improved ABS test apparatus.

[0002]

2. Description of the Related Art Conventionally, an anti-lock brake system is known which can prevent a tire from slipping due to locking of a wheel at the time of sudden braking or braking on a slippery road surface, thereby ensuring a stable vehicle posture and directional stability. It is. Vehicles equipped with this ABS cover a wide range from trucks to passenger cars. In recent years, some specific vehicles (for example, 10
(Trailers over 13 tons or tractors over 13 tons) are obliged to install ABS, and the details of the performance test are defined in the technical standards for ensuring the confirmation of their safety performance.

[0003] The test items are a bench braking force test and AB which serve as criterion data for an energy consumption test described later.
It was determined whether the road u (friction coefficient) of the S test satisfies the standard road surface conditions from 40 km / h during braking to 20 km / h.
Adhesion coefficient (K value) calculation test to measure and determine the adhesion coefficient from the deceleration time until, braking efficiency assurance test to determine how effectively the frictional resistance of the test road surface is controlled by braking efficiency measurement, ABS operation A lock avoidance performance confirmation test that directly checks the locked state of the braking wheels during braking, a brake control followability of the vehicle against an extreme change in the road surface u of the test road surface, a performance confirmation test for a drop in the so-called dive adhesion coefficient, and a jump-out The performance confirmation test for the increase in the adhesion coefficient (the road surface transfer test including both) is a performance confirmation test in which the former jumps from a high μ road to a low μ road and the change is a decrease in the adhesion coefficient of the road surface. / H and 8
Implement at a specified speed of 0 km / h. On the other hand, the latter is a performance confirmation test in which the road surface jumps from a low μ road surface to a high μ road surface and the change is an increase in the adhesion coefficient, and is performed at a specified speed of 50 km / h. In addition, a performance confirmation test (split test) on a non-uniform road surface for confirming vehicle controllability and vehicle stability on a road surface having extremely different right and left u at a braking initial speed of 50 km / h, and a constant value in an ABS operation state It consists of an energy consumption test for examining the residual braking capacity after conditional braking.

[0004]

The ABS test items include those performed while the test vehicle is stopped and those performed while the vehicle is running. Particularly, the latter is performed when the ABS is operating or not operating. In many cases, a braking operation is performed. For example, in the K value calculation test, in order to check whether or not the road surface u (friction coefficient) of the ABS test satisfies the standard road surface condition, the air pressure adjusted near the lock limit pressure in a state where the ABS is not operated is determined. Apply braking by using the 4
The adhesion coefficient is measured and determined from the deceleration time from 0 km / h to 20 km / h. Such a K value measurement test is performed on a low μ road, a high μ dry road, a high μ wet road, and a loaded or empty vehicle. In both cases, the number of times of measurement is measured three times each. However, since it is necessary to check the brake air pressure up to the lock limit, the number of times until the measurement is increased and the measurement time is extremely long.
In the case of the K value measurement, the brake operation is performed in the vicinity of the lock limit, so that the brake lining temperature rises, thereby decreasing the lining μ, making it difficult to perform an accurate braking test.

In the energy consumption test, there is an ABS operation test step from the initial braking speed Vo to 15 km / h in addition to the baseline measurement step and the air consumption test step performed at the time of stopping. Final speed (1
Unless the braking is immediately released at the time when the speed reaches 5 km / h), an error in the operation time occurs, which is disadvantageous in performance.
Further, in each of the above tests, it is necessary to output a brake signal and a vehicle speed signal to a printer or the like in conjunction with the brake operation, so that the operation becomes complicated.

The present invention has been made in view of the drawbacks of the prior art, and
ABS with brake operation such as value measurement and energy consumption
It is an object of the present invention to provide an ABS test apparatus capable of performing accurate measurement while rationalizing a braking operation as much as possible in a test. Another object of the present invention is to provide an ABS test apparatus capable of quickly releasing the braking when a predetermined deceleration speed is reached, thereby obtaining highly reproducible measurement data even when the same test is repeated. The purpose is to provide.

[0007]

According to the present invention, for example, the above-mentioned K value measurement or AB
In an ABS test apparatus for performing an S operation test, a detecting means for detecting depression of a brake petal at the first vehicle speed is provided, and at least a brake signal is output based on a detection signal from the detecting means. Vehicle speed detection signal generating means for transmitting a signal when the vehicle reaches a second vehicle speed (C vehicle speed), which is the final braking vehicle speed, after the brake operation by depressing the pedal; It is characterized in that the braking can be automatically released based on a signal from the generating means.

[0008]

According to this technical means, since the braking operation frequently performed in the ABS test and various signal outputs accompanying the braking operation can be transmitted to the printer in conjunction with the operation of the brake pedal, the ABS performance test items can be set. In addition to being able to perform the test in a short time and effectively with a limited number of test personnel, the burden and skill of the tester are greatly reduced, safety is also favorable, and printout can be reliably performed at the time of braking. In addition, the test accuracy is improved. In addition, since the braking is automatically released when the vehicle speed reaches the C vehicle speed, it is easy to perform the energy consumption test and the K value measurement repeatedly by running the vehicle on the original test road immediately and in a short time. I can do things.

In the case of the K value measurement, the braking operation is performed near the lock limit, so that the temperature of the brake lining rises, and the lining μ decreases, so that an accurate braking test cannot be performed. Since the braking is automatically released when the vehicle speed has been reached, unnecessary increase in brake temperature can be prevented, and the above-mentioned disadvantage can be easily solved.

Further, in the ABS operation test step from the braking initial speed Vo to 15 km / h, the braking operation starts at 15 km / h.
15km / h (C speed) to apply full braking to h
If the braking is not immediately released at the point of time, an error in the operation time occurs, which is disadvantageous in performance. Therefore, according to the present invention, when the vehicle speed reaches the C vehicle speed, the brake release timing can be known by the LED display and the buzzer sound, the error of the operation time can be eliminated, and a test method with high data reproducibility can be obtained from this aspect. Can be done.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, dimensions, materials, shapes, relative arrangements, and the like of the constituent means described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just FIG. 2 shows a pneumatic circuit around a brake related to the ABS test apparatus. 4A is the main air tank,
And OFF pressure switch 14D is the the tank 4A the pressure is air pressure governor PG set pressure _{P 1} by air supply from the air compressor 14 through the electromagnetic valve 14B and the check valve 14C, as shown in FIG. 3, LED14
e turns off and it can be determined that charging is completed. And the pressure of the main air tank 4A is specified pressure _(P 1 -a)
When the pressure falls below, the pressure switch PS returns and the LED
The lighting of 14e is performed. FIG. 3 shows such a compressor 1
4 / Chart diagram showing the operating state of the pressure switch PS / LED 14e, showing the case where the pressure switch PS is normally closed. When the pressure switch PS is normally open, the ON / OFF operation reverse to the above is performed.

Therefore, whether or not the charging is completed can be determined by the display of the LED 14e. In particular, in the energy consumption test method, it is possible to easily determine the full charge of the ABS operation test step and the baseline measurement step performed during running. The discharge side of the main air tank 4A is connected to a trailer air tank 4E, a rear air tank 4B and a front air tank 4C via a reducing valve 14F and a check valve 19A, and the auxiliary air tank 4D is connected to an electromagnetic valve 15B. It is connected via a check valve 15C.

The rear air tank 4B and the front air tank 4C are connected to respective brake circuits 13R, 13R via a brake valve 16 and double check valves 12C, 13C.
The auxiliary air tank 4D supplies air pressure to auxiliary equipment such as a clutch booster and an exhaust brake, which is supplied to 12F and performs braking based on known ABS control.
The trailer air tank 4E is connected to the dummy tank 4F via a dual relay valve 18 which operates in response to a trailer brake signal or an air pressure signal from the front / rear brake circuit together with the trailer emergency circuit.
Is supplied with air pressure.

The main tank 4A is provided with an air regulator 10 having a pressure gauge 10a, a switching valve 11A, and solenoid valves 12B and 13 for measuring a K value (adhesion coefficient) of a test road surface.
The adjusted air pressure can be supplied to the double check valves 12C and 13C of the corresponding brake circuits 12F and 13R via B.

FIG. 1 is an overall block diagram showing an ABS test apparatus according to an embodiment of the present invention. As shown in FIG.
Brake circuit 13 for front wheel or rear wheel via 1A
It is configured to be selectively connectable to the electromagnetic valves 12B and 13B that conduct to R and 12F. The boundary sensor 8B is formed by a diffuse reflection type photoelectric sensor provided at a side portion of a test vehicle (not shown), for example, at a step near the front axis, and has, for example, 700 n.
m red LED and a photo IC as a light receiver.

The reflection plate 8A is disposed at a lateral position off the road surface 2 so that the boundary sensor 8B can operate when the center of the front shaft of the test vehicle is positioned on the road surface boundary line 2a. Then, as shown in FIG. 9 (A), when the ABS-equipped test vehicle is driven from the low μ road to the high μ road or from the high μ road to the low μ road, when the front axis passes through the boundary line 2a, The reflector 8A faces within the beam width of the boundary sensor 8B, and a trigger pulse-shaped boundary line passing signal is output from the sensor 8B to the centralized control box 20 described later.

Reference numeral 20 denotes a centralized control box for performing overall control.
The control signals for B and 13B, the filling control signal for the brake air tank, and the shutoff control signal for the auxiliary device tank are sent to the corresponding solenoid valves 14B and 15B, respectively. In response to the brake signal from the brake pedal switch 31 and the μ jump signal from the boundary sensor 8B, a brake trigger and a μ jump trigger are sent to the fifth wheel amplifier 50, and a brake signal and a μ jump signal are sent to the analog printer 40 side. It is configured to be possible.

The fifth wheel amplifier 50 is a fifth wheel speed / distance meter with an ABS test function, and outputs a vehicle speed signal obtained from the fifth wheel detector 5 from the control box 20. And a μ jump trigger to output a vehicle speed signal to the printer 40, and output a signal when the vehicle speed reaches the braking end speed (C vehicle speed) of the K value measurement or the energy consumption test. The C vehicle speed switch 36 is operated. The fifth wheel is a floating wheel attached to the rear end of the test vehicle as is well known, and a vehicle speed detector 5 is mounted at the center of the floating wheel. The brake signal, the C vehicle speed output, and the like provide an outside lamp display 42 via a relay box 41.

The distortion amplifier 60 includes a steering angle meter 61,
The signals from the pressure pickups 62 to 64 are respectively supplied to the front tank 4C, the rear tank 4B, and the dummy tank 4F,
That is, a steering wheel angle signal required for a performance confirmation test (split test) on a non-uniform road surface, a front tank pressure, a rear tank pressure, a dummy tank pressure, etc. required for an energy consumption test are amplified and output to the printer 40 side.

The printer 40 uses an input-insulated analog printer in order to avoid noise to the ABSCPU (not shown), and outputs the vehicle speeds of the front and rear wheels taken from the wheel speed sensors together with the above-mentioned brake signal and vehicle speed output. The signal can be recorded. The hit point thermometer 70 detects the temperature in the vicinity of the brake lining, and when the lining temperature increases, the lining μ decreases, and the accurate AB
S test cannot be performed. Therefore, the test is set to start when the temperature is around 100 ° C. 80 is a generator.

FIG. 4 is a detailed circuit diagram of the centralized control box. A boundary sensor circuit for receiving a μ jump signal and outputting a μ jump trigger to the fifth wheel amplifier upon receiving a μ jump signal during a road transition test, and calculating an adhesion coefficient. A K value measurement circuit for testing, a brake signal circuit C at the time of ABS operation, a vehicle speed detection circuit which is a main part of the present invention, a circuit for an energy consumption test, and the like are incorporated.

These circuits will be described below according to the functions described above.
The description will be made according to the S test order. First, after performing a bench braking force test, which serves as determination reference data for an energy consumption test described later, a test for calculating an adhesion coefficient (K value) of an ABS test road surface u is performed. The test was performed by removing the fuse of the ABS control unit (not shown) and deactivating the ABS.
Approximately 50km / h to 20km / h on roads and high μ roads
While applying braking at the braking pressure just below the lock limit, the sticking coefficient (K value) is measured and determined from the deceleration time from 40 km / h to 20 km / h. Therefore, in this test, the initial braking speed exceeding 40 km / h It is necessary to apply the adjusted air pressure to the front shaft or the rear axle side without any fluctuation while applying braking to 20 km / h, while the adjusted pressure is applied during the braking operation. Therefore, it is necessary to take measures to enable forced release or emergency braking if necessary. Therefore, in the above-described circuit, a device for solving these problems is set with discipline.

FIG. 5 shows a brake signal circuit and a C vehicle speed detection signal circuit extracted from the entire circuit shown in FIG.
7 shows a K value measuring circuit, and FIG. 7 shows a main part pneumatic circuit obtained by extracting a K value measuring portion from the entire circuit shown in FIG. First, the output side of the regulator 10 of the pneumatic circuit shown in FIG.
And the solenoid valves 12B, 13 of the electric circuit shown in FIG.
B is connected to the solenoid valve 12B on the front shaft side via the changeover switch 11a. Brake signal circuit Pressing the brake pedal (not shown), microswitch 31 provided on the pedal is turned ON, the relay X ₁ is energized, the two relay contacts X ₁ is turned ON, the printer 40
The brake signal is sent to the side of the Olympics amplifier 50 and the brake trigger signal is sent to the Olympics amplifier 50 side.

As shown in FIG. 6, when the KTEST switch 37b is turned on and the 24V power supply 21 is applied to the circuit through the fuse 22, the brake switch 37e is activated at the time of the initial braking speed exceeding 40 km / h. the by turns oN the relay X ₃ is energized the relay contact X ₃ is energized electromagnetic valve 12B turned oN, air pressure regulated from the air regulator 10 is supplied to the corresponding brake circuit 12F, the braking is started . Incidentally, the air pressure is 1 Kgf / cm ² is almost low μ road, the high μ road 7~8Kgf / cm ²
Is set to The brake circuit 12F is connected to the brake valve 16 of FIG. 1 via a double check valve 12C.
When it is necessary to perform emergency braking during the braking, the emergency braking can be performed by stepping on the brake valve 16.

BRAK when the remote switch 37b is connected
X when E button 37c or remote switch 27 is turned ON
₃ relay is operated, _{X 3} relays a be OFF the ON switch _{X 3} 37e and the remote switch 27 relay contacts are closed _{X 3} relay contact 37c remain operating acts as a self-holding circuit.

[0026] In addition, or once _{X 3} relay 37a which is turned ON to OFF the K test switch 37b press the OFF button of the remote switch 27, or _{X 2} relay contact 37
When the test is released by a wheel lock or the like during the braking operation, the brake is easily released by performing the above operation because the wheel is not turned off unless f is operated. X ₂ relay contact 3
Reference numeral 7f denotes the above-mentioned C vehicle speed signal which operates at a speed lower than the C vehicle speed and serves as an automatic braking release signal. When the remote switch 27 is not in contact, the operation is the same as described above except that the remote switch 27 does not function. 37h is a switch used when it is desired to temporarily turn on the solenoid valve 12B for checking the operating air pressure after pressure adjustment, etc. The solenoid valve 12B is automatically turned off by releasing the hand for an automatic return mechanism. It is turned off.

[0027] Therefore, according to this circuit, unless forced cutoff or the C cars by a remote switch 27 (20km / h) speed of the relay _{X 2} at arrival time relay contacts 37f does not turn OFF the OFF or KTEST switch 37b, the air Supply continues. And the vehicle speed is 20 km / h
, And C based on the signal from the fifth wheel amplifier 50
Vehicle speed switch is turned ON, thereby the relay _{X 2} is excited _{X 2} relay contacts 37f is OFF, in order to be released excitation of the relay _{X 3} and _{X 3} relay contact 37g is turned OFF, energization of the solenoid valve 12B Is released, the air pressure in the brake circuit 12F is released to the atmosphere, and the braking is released. Thereby, the brake can be applied up to 20 km / h while applying the adjusted air pressure to the front shaft or the rear shaft without causing a fluctuation, and on the other hand, forcible release or emergency braking is performed as required during the braking operation. I can do things.

Next, after performing a braking efficiency assurance test and a lock avoidance performance confirmation test, a so-called dive and jump test (roadway transfer) for confirming the braking control followability of the vehicle with respect to an extreme change in the road surface u of the test road surface. In particular, in the road surface transfer test, it is necessary to accurately detect the boundary position between the boundary between the high μ (low μ) road surface and the low μ (high μ) road surface. The vehicle speeds at 40 km / h and 80 km / h in the dive test and 50 km / h in the pop-up test are very difficult to accurately detect because the specified speed varies greatly. Therefore, in the present embodiment, the following measures are taken.

FIG. 8 shows a boundary sensor circuit portion extracted from the entire circuit shown in FIG. 3. Reference numeral 33 denotes a constant voltage circuit comprising a series diode 33a, a three-terminal regulator 33b, a capacitor, and the like; 34, a timer IC 34a;
1. A one-shot multi-circuit formed by combining capacitors and the like. When a power switch 32 is turned on, a 24V power supply 21 is connected to a series diode 34 via a fuse 22.
a, is supplied to the boundary sensor 8B and the one-shot multi-circuit 34, etc.
Is turned on to notify the energization state of the boundary sensor 8B.

On the other hand, as shown in FIG. 9 (A), the test vehicle equipped with the ABS is driven from the low μ road to the high μ road or from the high μ road to the low μ road, and while applying the braking from the braking start position 2b, When the front axis passes through the boundary line 2a, the reflector 8A faces within the beam width of the boundary sensor 8B, and the sensor 8B
A more trigger pulse-like boundary line passing signal is transmitted to the connector 17a.
Is output to the one-shot multi-circuit 34 via the. The passing signal largely depends on the width of the reflector 8A and the vehicle speed. When the vehicle travels at a vehicle speed of about 90 km / h as shown in FIG. 9B, the pulse width is as short as about 0.03 seconds. Becomes Therefore, every time the one-shot multi-circuit 34 including the timer IC 34a supplies the boundary passing signal 7c, a boundary detection pulse signal (7d) having a constant width determined by the variable resistor R1 is applied to the base side of the switch transistor 26, outputs μ jump signal by driving the relay X ₆ in the fifth wheel amplifier 50 to be described later s husband, it is possible to perform predetermined Noriutsuri tests on the basis of the signal.

In addition, in particular, the sensor may be used as a light projector, for example.
A diffuse reflection type photoelectric sensor using a 00 nm red LED and a photo IC as a light receiver (for example, GSR05 (trade name))
R (manufactured by Takenaka Electronics Co., Ltd.), as shown in FIG. 9 (C), the light-receiving sensitivity width spreads out at a close distance of 1 to 4 m, but becomes almost parallel at 4 to 8 m. Therefore, when the vehicle travels, the distance from the reflector installation position cannot always be set accurately, but in the case of the present embodiment, even if the distance fluctuates in the range of 4 to 8 m, accurate detection is possible.

Next, after performing a split test, an energy consumption test is performed. The energy consumption test consists of three steps: a baseline measurement step, an ABS operation test step, and an air consumption test step. The energy consumption measurement electric circuit shown in FIG. 10 extracted from the entire circuit of FIG. 2 and a pneumatic circuit for measuring energy consumption shown in FIG. 11 extracted from the whole air circuit of FIG.

First, in the baseline measurement step, the changeover switch 38f is switched to the manual side, the air tank pressure is fully charged as shown in FIG. 3, and this is confirmed by the LED 14e, and then the electromagnetic force of the main tank 4A and the auxiliary tank 4D is checked. Energize each valve. The air from the compressor 14 side is released to the atmosphere through the solenoid valve 14B by the energization.
Since the main tank 4A is equipped with a check valve 14C,
The charge is cut without releasing the air in the tank 4A, while the auxiliary equipment tank 4D is cut similarly. Thereafter, the brake pedal is fully depressed for 20 to 30 seconds, and the baseline measurement for reading the pressure of the dummy tank 4F at that time is performed.

Next, the process proceeds to an ABS operation test process. First, after the air tank 4A pressure is fully charged, the changeover switch 38f is switched to the Auto side, the charge from the compressor 14 is cut off, and the vehicle enters the test path 2 at a predetermined initial braking speed Vo, and the test vehicle completely enters. Then release the clutch and depress the brake pedal to apply full braking,
Microswitch 31 provided on the pedal as shown in FIG. 5 is turned ON, the relay X ₁ is excited, the two X ₁
The relay contact turns on and the current limiting resistor 23
Sends out a brake trigger signal also Olympic amplifier side brake signal via, is energized solenoid valve 14B of the relay X ₄ is excited by X ₄ relay contact 38g is ON and the main air tank 4A simultaneously, whereby said Braking is started with the charge cut. Then, when the vehicle speed becomes 15 km / h, the C vehicle speed switch 36 is turned on based on a signal from the fifth wheel amplifier 50, thereby turning on (or lighting) the LED 38C display and blowing the buzzer 38e. You can know the brake release timing. Air charge during braking is allowed, so when the brake pedal is depressed,
The air tank 4A is automatically charged. And without using the foot brake, return to the starting point at a very low speed,
The running is repeated again, and when the two runnings are completed, the vehicle stops without using the foot brake and ends.

The ABS operation test is performed at a speed of 50 km / h to 1
Since the operating time is up to 5km / h, it is 15km
The braking time of less than / h results in an error in the operation time and is disadvantageous in performance. However, in the above embodiment, the LED display and the buzzer sound at the time of reaching 15 km / h.

After confirming that the total of the operation time (t1 + t2) has become equal to or longer than the time t in the divided ABS operation test, five full brake operations are performed, and each shaft tank pressure (rear tank pressure) after the last brake operation is performed. Pressure, front tank pressure) and dummy tank pressure. Thus, the predetermined ABS test ends.

The flicker circuit for displaying the lamp outside the vehicle comprises a blinking time setting timer 39b and a switch 39a.
Relay X ₅ by the relay contacts of the timer is ON
Is excited, the blinking display LED 39c and the lamp outside the vehicle are turned on, and it becomes easy for a monitor or an examiner outside the vehicle to grasp the test transition status as a guide for determining the lock time.

[0038]

As described above, according to the present invention, an ABS test apparatus capable of performing accurate measurement while rationalizing the braking operation as much as possible in an ABS test involving a braking operation such as K value measurement and energy consumption. You can get it. Further, according to the present invention, it is possible to obtain measurement data with high reproducibility even when the same test is repeated in order to release the braking immediately when a predetermined deceleration speed is reached or to inform the brake release timing. I can do it. And so on.

[Brief description of the drawings]

FIG. 1 is an overall block diagram showing an ABS test apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a pneumatic circuit around a brake related to the ABS test apparatus.

FIG. 3 shows the air compressor / pressure switch /
FIG. 4 is a chart showing an LED operating state.

FIG. 4 is an overall circuit diagram showing a detailed configuration of a centralized control box shown in FIG.

FIG. 5 is a main part circuit diagram showing a brake signal circuit and a C vehicle speed signal circuit extracted from the entire circuit shown in FIG. 4;

6 is a main part circuit diagram showing a K value measurement circuit extracted from the entire circuit shown in FIG. 4;

7 is a main part pneumatic circuit extracted from a circuit part related to K value measurement in the pneumatic circuit shown in FIG. 2;

8 is a main part circuit diagram of a signal flow portion of a boundary sensor extracted from the entire circuit shown in FIG. 4;

9 (A) is a layout diagram showing a positional relationship between a road surface and a boundary sensor in a transfer test, FIG. 9 (B) is a waveform diagram of an output signal from the sensor, and FIG. 9 (C) is a diagram showing a relationship between a reflector (reflector) and a boundary sensor. It is a graph which shows the measurable range corresponding to distance fluctuation.

10 is a main part circuit diagram showing a circuit portion related to an energy consumption test extracted from the entire circuit shown in FIG. 4;

11 is a main part pneumatic circuit extracted from a circuit part related to an energy consumption test in the pneumatic circuit shown in FIG. 2;

[Explanation of symbols]

 Reference Signs List 20 central control box 31 brake pedal switch 36 C vehicle speed switch 40 printer 50 fifth wheel amplifier 5 fifth wheel detector

Claims (1)

(57) [Claims] 1. An ABS test vehicle traveling on a test road is depressed by a brake pedal at a first vehicle speed and decelerated to a second vehicle speed (hereinafter referred to as C vehicle speed) by various deceleration operations. In an ABS test apparatus configured to be able to measure a road surface adhesion coefficient (hereinafter referred to as a K value) and an ABS performance on the test road based on a characteristic value, a detection unit for detecting a brake pedal depression at the first vehicle speed is provided. A vehicle speed detection unit configured to transmit at least a brake signal and a braking start vehicle speed signal to the printer based on a detection signal from the detection unit, and to transmit a signal when the second vehicle speed is reached after the braking operation. An ABS test apparatus comprising signal generating means, wherein said braking can be automatically released based on a signal from said generating means.