FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
A MODULAR VEHICLE TESTING SYSTEM
2. APPLICANT(S)
MAHINDRA & MAHINDRA LTD.
GATEWAY BUILDING, APOLLO BUNDER, MUMBAI - 400001, MAHARASHTRA, INDIAN.
The following specification describes the invention.

Field of the Invention
The present invention relates to a comprehensive modular system and method for testing vehicles. In particular the invention relates to testing off road vehicles including tractors.
Background of the Invention
It is well established fact that the vehicles are to be tested or validated
at on road real life conditions to estimate various performance
parameters such as fuel consumption. However, there are
impediments for this kind of on road testing due to factors such as ever increasing fuel prices, transport, site running costs etc. Further it is important to conduct repetitive tests for confirming with repeatability aspect. The problems in on road testing aggravate for failure analysis on site with relatively limited instrumentation leading to considerable time consumption. This reflects in delay in launching vehicle or developing new product.
In case of off road vehicles such as tractors, there are combination of loads / variables to be tested, they are as follows:
√ Vehicle inertia due to its weight can be simulated on test facility. √ Power Take Off loading, for tractors / Agricultural purpose vehicles √ Hydraulic loading for hydraulic applications on Off Road vehicle
hydraulics application of loader & backhoe. √ Durability testing of transmission driveline with loading through
rear wheel loading with help of DC Dynameters. √ Varied environmental conditions such as ambient temperature (Heaters & HVAC) & Moisture, dust etc.

The conditions wherein tractor is operated also demands testing for vertical acceleration in which case the wheels experience vertical displacement and vibration due to obstacles / surface irregularities in the field.
To overcome these problems there is an alternative in terms of testing or validating vehicle using chassis dynamometers that are used to simulate road condition. The chassis dynamometer comprises of rollers/ set of rollers corresponding to individual wheels of the vehicle to create reaction and / or traction. However these conventional chassis dynameters suffer from the limitation that they are provided with either front wheel and / or rear wheel driven rollers only and are not capable of testing vehicles for combination of above mentioned loads / variables.
There is a need to provide a testing facility to simulate the field conditions in terms of variables like loads / combination of loads, temperatures, vibrations, environmental conditions etc.
It may be noted that in the context of the present invention, off road vehicle term is used to include vehicles, in particular slow moving tractive vehicles including tractor, trolleys, earth moving equipment, JCBs but not limited to it. The definition of the off-road vehicle varies as per respective standards in various countries. The term off-road vehicle used in the present invention hereinafter should not be construed to be the definition as per the standards / conventions in India or respective countries. The off-road vehicle in the context of this invention in particular include vehicles with maximum speed of 40 km/h that are used alone or in combination with any other means to cater to tractive load.

Testing systems are reported in the prior art, they are as follows:
United States Patent 3680368 discloses system for measuring tractive power with controlled application of load. The system measures horsepower at the drive wheels of a truck tractor under conditions which very closely simulate actual road conditions. For each set of drive wheels there are a driver roll and an idler roll mounted on a frame for rotatably supporting the drive wheels, and a dynamometer is connected to measure the power transmitted from the tractor drive wheels to the drive roll. A hydraulic cylinder and piston rod unit is mounted to the support frame and extends rearward. A flexible link connects the movable end of the hydraulic cylinder and piston rod unit to the fifth wheel on the tractor for forcing the tractor wheels against the driver roll while removing weight from the idler roll -- thus transmitting the entire torque at the drive wheel to the driver roll while leaving full control of the applied load in the hands of the operator. The driver roll and idler roll for one set of drive wheels is mounted on a movable chassis for accommodating all wheel bases; and the idler rolls are independently movable relative to their associated driver rolls for controlling the distribution of traction between the driver and idler rolls. In a modification, the pulling angle of the flexible link may be set for further controlling the application of torque to the driven roll.
United States Patent 5154077 discloses chassis dynamometer. It comprises of a load roller and a free roller both of which are driven by a tested object, such as, an automotive vehicle. The load roller is drivingly connected to a dynamometer and mounted onto a first rotary shaft for co-rotation therewith. The free roller is mounted on a second shaft such that the free rofler is rotatable relative to the second shaft.

A flywheel is mounted on the second shaft co-rotatably therewith for forming a simulated inertial load. A power transmission unit, such as, a combination of timing pulleys and a timing belt is provided for transmitting a driving power from the first shaft to the second shaft such that the second shaft is rotated faster than the first shaft. Since the second shaft i.e. the flywheel is rotated faster than the first shaft, i.e. the load and free rollers, an inertial load created by rotation of the flywheel is increased so that a weight of the flywheel can be reduced.
United States Patent 5450748 discloses multiple functional chassis dynamometer capable of performing a multiplicity of tests and of simulating a variety of conditions, including wind resistance, weight of the vehicle and grade or slope of a road, includes first and second pairs of rolls for supporting the tires of a vehicle to be tested. An electric drive motor is connected with the roffs to drive them, and a single flywheel and associated eddy current motor are connected with the rolls to impart various levels of apparent inertia to the rotational movement of the rolls for thereby simulating the various conditions encountered by a vehicle travelling on a road. The frame is of open construction and the drive motor, eddy current motor, flywheel, rolls and associated components are confined within the periphery of the frame.

However the systems mentioned in the prior art suffer from following drawbacks:
√ Lack of provision to test combination of loads / variables
√ Lack of provision to test varied power outlets in particular in case of off vehicles such as tractor in terms of power to wheels, PTO, hydraulic power at lower link hitch point and top link draft sensing point; √ Lack of provision to simulate vertical acceleration / vibration conditions and test the vehicle for the same for rear and/ or front wheels; √ Lack of testing vertical acceleration effect and torque simultaneously; √ Lack of flexibility to adjust distance between rollers corresponding to rear and front wheel (axle) of the vehicle, imposing limitation on testing varied capacity vehicles; √ Lack of testing effects at varied environmental conditions; √ Lack of provision to simulate vehicle inertia and simultaneously providing traction for wheels √ Lack of rear wheel loading using DC dynamometers. √ Lack of provision to test 2 Wheel Drive as well as 4 Wheel Drive vehicles √ Lack of provision to test off road vehicles such as tractor for load due to soil resistance at the tractor top link
There is unfulfilled need to develop a comprehensive testing system comprising aforementioned lacking provisions and combination in the prior art for vehicles, in particular for off road vehicles such as tractors.

Summary of the Invention
Main object of the invention is to provide a system and method for testing vehicles. Further object of the invention is to provide a comprehensive system and method to test off road vehicles such as tractors.
Another object of the invention is to provide a testing system and method thereof to test off road vehicle such as tractor for combination of loads / variables such as vehicle inertia simulation, power take off (PTO) loading, hydraulics power outlet and combination thereof.
Another object of the invention is to provide a testing system for testing vehicles under varied environmental conditions such as ambient temperature, moisture, dust etc.
Yet another object of the invention is to provide a testing system to simulate vertical acceleration / vibration conditions and test the vehicle for the same for rear and/ or front wheels.
Another object of the invention is to provide rollers for simulating vertical acceleration conditions.
Another object of the invention is to provide a testing system to test vertical acceleration effect and torque simultaneously.
Yet another object of the invention is to provide a testing system to provide flexibility to adjust distance between rollers corresponding to rear and front wheel (axle) of the vehicle.

Yet another object of the invention is to provide a testing system to simulate vehicle inertia and simultaneously providing traction for wheels.
Yet another object of the invention is to provide a testing system to eliminate or reduce the vehicle testing/ validation dependency on road or field testing.
Yet another object of the invention is to provide testing system to test 2 wheel drive as well as 4 wheel drive vehicles.
Yet another object of the invention is to provide comprehensive testing system to test off road vehicles such as tractor for load due to soil resistance at the tractor top link.
Another object of the invention is to provide modular testing system
comprising modules for testing various vehicle variables / performance
parameters.
Yet another object of the invention is to provide front roller assembly
module for the said testing system.
Yet another object of the invention is to provide rear roller assembly module for the said testing system.
Yet another object of the invention is to provide vertical acceleration simulation module for the said testing system.
Yet another object of the invention is to provide timing belt driven clutch enabled inertia flywheels module for the said testing system.
Yet another object of the invention is to provide regenerative DC Dynamometer module for the said testing system.

Yet another object of the invention is to provide PTO Loading Dynamometer & controller module for the said testing system.
Yet another object of the invention is to provide hydraulic loading module for the said testing system.
Yet another object of the invention is to provide environmental condition simulation module for the said testing system.
Thus in accordance, one aspect of the invention provides a comprehensive modular testing system comprising √ Base frame structure module √ front roller assembly module √ rear roller assembly module √ vertical acceleration module √ timing belt driven clutch enabled inertia flywheels module √ regenerative DC dynamometer Module √ PTO loading dynamometer & controller Module √ hydraulic loading module √ unmanned system module √ vehicle loading & unloading on the chassis. √ environmental condition simulation module √ control system module comprising of accelerometers & data acquisition system
wherein rollers of the said front and / or rear roller assembly module comprises of detachable profiled wedge blocks mounted on the roller outer surface at diagonally opposite locations wherein the said rollers are in one of the embodiments made up of pipe

wherein the said front roller module can be distanced apart from the rear rollers with the help of automated motorized mechanism, to suit the test vehicle wheel base wherein the front & rear rollers are connected to each other with timing belt to enable simultaneous rotation of both front & rear rollers;
wherein regenerative DC dynamometer is used to load the drive train through rollers in contact with the rear tyres of the vehicle to be tested;
wherein varied inertia on vehicle is simulated by clutching & declutching
flywheels
of the time belt drive clutch enabled inertia flywheel module;
wherein the dynamometers are connected to the PTO shaft of the rolling & jumping tractor with help of propeller shaft & the controllers are interfaced with the said control system;
wherein the loads at tractor top link due to soil resistance are simulated using external hydraulic system;
wherein a pneumatic control system is provided for loading and unloading the vehicle on & off the rollers obviating manual intervention wherein disc brake arrangement is provided to avoid the roller rotations when the vehicle is mounted & loaded and unloaded on & off the rollers; the pneumatic control system has interlock which ensures the disc brakes are actuated before mounting & dismounting the vehicle on & off the rollers.

Brief Description of the Drawings
Features and advantages of the invention will become apparent in the following detailed description and the preferred embodiments with reference to the accompanying drawings.
FIG. 1 Schematic of the Elevation of the System
FIG. 2 Schematic of the Plan of the System
FIG. 3a Schematic of the front roller
FIG. 3b Schematic of the rear roller
FIG. 4 Schematic of loading / unloading arrangement
FIG. 5 Schematic of the control room with controlled environment
Detailed Description of the Invention
FIG.1 illustrates schematic of the layout of the testing system. Elevation is depicted in this Figure. The system comprises of base structure module 6 grouted in the pit. Base structure module supports the other modules of the test facility and also the test vehicle against all the loads (i.e. Vibrations & forces etc). The vehicle to be tested is indicated by numeral 3 in this representation. Though it is shown as tractor, the invention and the scope is not limited to it. The PTO shaft 9 of the tractor is connected to the dynamometer 8. Control system 1 is installed in the proximity of the base structure module 6. The timing belt 5 connects front and rear rollers enabling testing of two wheel as well as four wheel drive vehicle types. The said testing system comprises of a provision in terms of external hydraulic system 2 to simulate loading conditions due to soil resistance on the tractor top link. Speed pick up 7 provided at the rear rollers has zero speed interlock, so that vehicle dismounting cylinders & brakes are applied to rollers only at zero speed for safety purpose. Front roller module 4 is mounted on linear bearing for wheel base adjustment.

FIG.2 illustrates top view of the testing system. As illustrated in the Figure, the front roller module 4 is adjustable with the help of automated motorized mechanism, so as to the distance between front & rear rollers can be varied to suit the test vehicle wheel base. Variable inertia arrangement 13 is provided to simulate different vehicles inertias. The inertia can be varied by clutching & declutching flywheels. Regenerative DC dynamometer 12 is used to load the drive train through rollers in contact with the rear tyres. The vehicle is equipped with accelerometers & data acquisition system to capture & analyze acceleration spectra. The acceleration spectra is simulated with the help of wedge blocks mounted on rollers & verified by accelerometers mounted on vehicles in same positions as that of field.
FIG.3a & 3b Illustrates roller details. One or plurality of detachable wedge blocks 17 are provided on the surface of the roller to generate vertical accelerations or vibrations experienced in the actual vehicle usage. The said wedge block is profiled so as to achieve desired vertical acceleration level. Design of wedge requires following input parameters such as acceleration in field applications at specified speed of vehicle, wheel diameter & test rig roller diameter. Number of wedges per roller could be varied as well to simulate desired conditions. In one of the embodiments the wedges are provided on front and / or rear rollers. The rollers in one of the embodiments are made up of pipe.

Figure 4 illustrates loading / unloading provision. Once the test is started by operator no manual intervention required. A pneumatic control system 19 is provided for loading and unloading of the vehicle on & off the rollers. The disc brake 18 is provided to avoid the roller rotations when the vehicle is loaded / unloaded on/ off the rollers. The pneumatic control system has interlock which ensures the disc brakes are actuated before mounting & dismounting the vehicle on & off the rollers.
FIG.5 illustrates the Test facility enclosed in control room 20 where the air heaters 21 are placed on top of vehicle 23 to simulate ambient temperature. Water tank with spray arrangement 22 is provided to simulate the rain conditions. And tank with fine dust 24 is placed in the room which is mixed with compressed air & thrown out on the test vehicle.
It is evident from the present invention that the comprehensive modular testing system for vehicles disclosed in this invention provides much needed system to simulate the field conditions in terms of combination of loads in particular for off road vehicles such as tractor, vary performance parameters, test vehicle for vertical acceleration (vibrations), simulate diverse ambient conditions obviating problems associated with actual road testing.