FORM 2


THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Slip Simulation Device for ABS Electronics Testing and method of testing thereof
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India

INVENTORS
Sandeep Anandrao Salunkhe and Preesty Thomas J
both Indian nationals of TATA MOTORS LIMITED,
An Indian company having its registered office at
Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
3 0 MAR 2009
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in
which it is to be performed.


FIELD OF INVENTION
This invention relates to the testing of Anti-Lock Brake System (ABS) ECU (Electronic Control Unit) and sensor testing which requires generating slip in the wheels of the vehicle and more particularly it relates to slip simulation device for anti lock braking system ( ABS) for vehicle.
BACKGROUND OF THE INVENTION
The Anti-Lock Braking System (ABS) system level test is required to ensure
robustness of electronic system.
The ECU constantly monitors the rotational speed of each wheel. When the ECU
detects that one of the wheel is turning significantly faster than the others, brake
hydraulic pressure to the wheel is increased so the braking force is re-applied and the
wheel slows down to the desired speed. In vehicles not equipped with ABS, the driver
has to manually pump the brakes to prevent wheel lockup.
To test the anti braking system (ABS) ECU as mounted on the vehicle currently
there is no such method in existence. With the proposed invention we can evaluate the
performance of ABS system electronics on vehicle at standstill condition.
OBJECTS OF INVENTION
The main object of the present invention is to provide a slip simulation device for anti lock braking system (ABS) for vehicle.
Another object of the present invention is to provide a slip simulation device for anti lock braking system (ABS) for vehicle which simulate the slip occurring on the wheels of the vehicle to generate ABS system actuation and to monitor behaviour of the system at time of braking.

SUMMARY OF INVENTION
In accordance with the present invention , a slip simulation device comprises; at least four dummy wheels (2,11) with braking arrangement, at least four Pneumatic cylinders (1,7), a metal fixtures (3,10) for holding the said dummy wheels The vehicle is mounted on the another vertical fixture (4,9) so as it free to rotate its wheels (5,12). The said dummy wheels (2,11) with braking arrangement are mounted on the said metal fixtures (3,10) and said dummy wheels (2,11) is engaged in friction with wheels ( 5,12) of vehicle. The braking of the said dummy wheels (2,11) can be achieved with said pneumatic cylinders (1,7) or by any other suitable actuation system. The said pneumatic cylinders is interfaced with programmable control system and is operated to achieve the level and sequence of braking to create slip in desired vehicle wheel.
BRIEF DESCRIPTION OF DRAWINGS
Figure-01-Shows test setup for mounting the vehicle in the position where slip can be generated in accordance with this invention.
Figure-02- Shows the side and top view of the setup exploring the exact placement of the dummy wheels in-line with the wheels of the vehicle.
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same,
In accordance with the present invention , a slip simulation device comprises; at least four dummy wheels (2,11) with braking arrangement, at least four Pneumatic cylinders (1,7), a metal fixtures (3,10) for holding the said dummy wheels
The vehicle is mounted on the another vertical fixture (4,9) which allows to rotate said wheels (5,12) freely . The said dummy wheels (2,11) with

braking arrangement are mounted on the said rigid fixtures (3,10) and said dummy wheels (2,11) is engaged in friction with wheels ( 5,12) of vehicle. The braking to the said dummy wheels (2,11) can be achieved with said pneumatic cylinders (1,7) or by any other suitable actuation system. The said pneumatic cylinders are interfaced with programmable control system and is operated to achieve the level and sequence of braking.
Now referring to figure-01, The said dummy wheels (2,11) are mounted on the said rigid fixture (3, 10) which provides the support for the said dummy wheel like (2,11) during the actuation and prevents vibrations produced at time of slip generation. The said dummy wheels (2, 11) are having the brake system which when actuated, creates a slip on the vehicle wheels (5, 12) of the vehicle.
The said brake system comprising brake calliper/shoe , brake lining and tandem master cylinder, wherein said brake calipper with brake lining ,which in turn connected to tandem master cylinder (TMC) which is actuated through pneumatic cylinder (1,7) to apply brakes on said dummy wheels (2,11) or a cable lever arrangement actuating the calliper /shoe of dummy wheel can be used
The braking on the said dummy wheels (2,11) can be actuated by means of brake Tandom Master Cylinder (TMC) and / or brake cable which can be controlled progressively or instantly to the level required as per test with the help of pneumatic cylinders (1, 7).
Referring to figure-02, wherein one set of pneumatic cylinder (1) and tandem master cylinder (TMC) (13) which is connected through brake lines to each dummy wheel ( 5,12) which is frictionally engaged to vehicle wheels.
The system can be programmed through Real time (RT) controller for the generation of slip for the various types of road surfaces like skid surface , icy surface or bump

road condition by changing the duration / pressure of braking system of said dummy wheel in the required sequences like high slip or low slip as per the test run.
The vehicle is put into driving mode by means of operating the clutch, gear, accelerator and brake system by using said real time (RT) controller as per the requirement.
The Pneumatic cylinders used to control Clutch Pedal, Gear Shift Lever,Accelerator Pedal,Brake Pedal,Front Right Wheel,Front Left Wheel,Rear Right Wheel,Rear Left Wheel of the test vehicle.
The braking system of test vehicle is programmed thourgh Rear Time (RT) in such a way that it runs as per the real life drive cycle.
The said pneumatic air cylinders (1,7) which are fitted to the said dummy wheel (2,11) for the simulation of the drive cycle of vehicle. The method of testing ABS of vehicle comprising;
i. Starting the vehicle by means of giving crank input; ii. Engaging the said clutch by pressing the said clutch pedal; iii. Transmitting the engine power to the wheels by presssing the said gear
shift lever as desired ; iv. Accelerating the vehicle to desired speed at which it should generate the
slip by press the Accelerator pedal; v. Actuating the desired dummy wheels after reaching desired speed of vehicle to generate additional torque required for slip by operating opposite wheel cylinder progressively or instantly to the level required depending on vehicle braking; vi. After vehicle braking is applied, the ABS system senses the required slip in vehicle wheels by relative speed difference in one of the wheels; the ABS system tries to equalize the brake force in the relative wheels, to avoid the skidding of the vehicle.

Thus we can create various low slip and high slip surfaces, by means of locking and unlocking the said wheels of test vehicle on the test setup to generate slip. Advantages of the present invention of generating slip.
Simple in design and no need of special arrangements.
Eliminates the need of chassis dynamometer/road simulator type setup.
System is much cost effective as it needs no costlier test equipment.
We can simulate the various test conditions, so there is less need of time
consuming road trials for functionality testing.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.
Dated this 26th day of March 2009
TATA MOTORS LIMITED By their Agent & Attorney

Karuna Goleria of DePENNING & DePENNING