MXPA00011230A - Portable roller dynamometer and vehicle testing method. - Google Patents

Abstract

A roller dynamometer is provided, having at least one supporting carriage having a rotatable roller and a dynamometer linked to the roller for measuring torque output of a vehicle. The carriages are rollable on a substrate for positioning under a vehicle. In one aspect, multiple dynamometer and roller units are provided, for engagement with multiple vehicle wheels, with the units being linked electrically for common control by a control unit that simulates either straight line or curved driving conditions. In a further aspect, the dynamometer is supported on the carriage by a rotary mount. In a further aspect, the rollers have a generally hourglass shape to permit vehicle wheel self-centering.

Description

PORTABLE ROLLER DINAMOMETER AND TEST METHOD FOR VEHICLE FIELD OF THE INVENTION The invention relates to a dynamometer and a test method for simulating road conditions, to test a vehicle having at least two drive wheels; and more particularly, to a dynamometer having rollers for coupling with the wheels of the vehicle, and which is relatively compact, inexpensive and portable. Furthermore, the invention relates to an apparatus and method that allows the simulation of driving conditions in a straight line and in curves. The invention can also be adapted for use with a vehicle having a single drive wheel such as a motorcycle.

BACKGROUND OF THE INVENTION Vehicle emission and maintenance tests are effective if the driving conditions of the vehicle can be effectively simulated. This is typically completed by means of the arrangement of a roller that has contact with the driving wheels of the vehicle, with the rollers being operably connected to a dynamometer to place a No. Ref .: 124639 controlled load on the rollers. The load amount will be a function of the rotational speed of the rollers (ie, the simulation speed of the vehicle), of the actual and simulated friction losses, and of a polynomial equation representing the wind resistance of the vehicle in particular. The dynamometer simulates two aspects of vehicle performance, called inertia and engine drag. In this case, the inertia is governed by the weight of the vehicle and the equivalent of the masses in rotation of the vehicle, with the device simulating in this way the inertia, based on this factor. The drag is simulated by the dynamometer, which applies resistance to the rollers, governed by the current speed of the vehicle and the wind resistance factor. The inertial energy can be provided by means of a steering wheel as well as the simulation by other means.

Conventional roller test standards for motor vehicles typically comprise one or more large rollers, with a single roller running through the left and right wheels of the vehicle. For example, the apparatus published in U.S. Pat. 3,554,023 (Geul); U.S. Patent 5,154,076 (Wilson et al) and U.S. Pat. 5,193,386 (Hesse, Jr. Et al), all are of this type. Also, it is known to provide a test assembly for use with a motorcycle that has contact with the single drive wheel of the vehicle (US Patent 5,429,004 -Cruickshan).

The conventional resistance of the dynamometer is provided by a braking mechanism such as an electric motor, a hydraulic brake, etc. However, other resistance generating means may be employed and the present invention is not limited to the use of any particular means of braking.

It is desired to provide a portable chassis dynamometer assembly, which can be easily transported to a test vehicle, such as a vehicle depot, and quickly and easily prepared to perform vehicle emission performance tests. This eliminates the need to take each vehicle to a specific test site separately. For this purpose, it is desired to provide a portable chassis test dynamometer assembly comprising individual subunits that can be transported separately and easily assembled in place without having to physically or subunit the subunits. mechanically. The solution proposed by the present inventors is to provide individual subunits of the left and right hand roller dynamometer, which can be simply placed on it. floor to the center of the wheels of the test vehicle. Such subunits can be linked electronically by means of a common control subassembly.

It is known from the provision of assemblies to test vehicles with two or more drive wheels (ie, wheels driven by the engine), comprised of individual rollers of left and right side. Either the rollers of such assemblies share a common axis or are connected by a bar or frame that traverses the pairs of rollers. See as an example the U.S. Patent. 5,193,386 (of Hesse, Jr. et al.) And W097 / 32189 (of D'Angelo). Because of the large framework required in such arrangements, they do not provide an easily portable dynamometer arrangement that would allow for easy transportation and placement. Assembly for such units at the test site would take time and would require specialized experts. Thus, such arrangements do not satisfy the need for a simple and easy test assembly. transport, which is also simple in its assembly for use in the test place.

An additional and useful feature of vehicle dynamometers is that they are capable of centering vehicle wheels on rollers. This can be accomplished by providing rollers in cut-cone-shaped pairs that decrease inwardly and toward each other to support the two opposed driving wheels (cf. de Hesse Jr., et al.). In this arrangement, the vehicle is centered between the individual left and right cut cone rolls. However, this arrangement requires that the left and right hand roller assemblies be either joined by a rigid frame or fixed to the floor to prevent a sliding sideways of the roller assemblies. Alternatively, the background releases left and right hand rollers that can move independently on a common rail, and that can be held in position when the rollers have been centered on the wheels of the vehicle (D'Angelo). However, this arrangement is still unsuitable for the use contemplated in this invention, because this requires a rigid and large frame or rail that joins the left and right hand rollers, which would be inappropriate for portable use. To complete the objective of a simple and easily portable assembly, it is desired to provide a simple means for centering a vehicle on the dynamometer assembly during the operation of the device. In the solution proposed by these inventors, this is provided without some third-party centering means, and in a manner consistent with the provision of left and right roller subunits lying on the floor.

It is also known to provide a logic circuit that independently controls the front and rear roller sets to test various vehicle front / rear load parameters, such as the change of position. See EPO 0 522 198 Al (from Yorikatso). However, the background does not suggest the use of logical circuitry to separately control the left and right roller assemblies that are not mechanically attached.

Conventional test devices based on dynamometers are typically large, heavy and correspondingly expensive. This results in part from the provision of a single roller, for contact with the left and right drive wheels of a vehicle, which is what wide enough for use with substantially all conventional vehicles, resulting in a large and heavy roller arrangement. This drawback can be solved by providing a test apparatus formed of separate left and right hand roller dynamometer subassemblies for the individual support of the vehicle's drive wheels, with the sub-assemblies not being mechanically attached to provide easy transportation and assembly. The individual dynamometer assemblies are linked only electronically through a controller. The individual dynamometers can thus be in communication with a common control unit to equalize the simulated loads between the drive wheels of the vehicle. This arrangement also allows to simulate a vehicle driven around a curve for unequal wheel loads and speeds between the individual units.

DESCRIPTION OF THE INVENTION An object of the present invention is to provide an improved roller dynamometer and a test method for simulating road conditions for testing a vehicle.

A further objective is to provide a roller dynamometer comprising several dynamometer assemblies, not mechanically linked to each other for a common rotational movement, each dynamometer assembly having contact with a single wheel of the vehicle, with an effective width of the roller dynamometer being variable by changing the distance between the individual units.

A further objective is to provide a roller dynamometer which can be used with any conventional vehicle, and which has the ability to simulate, driving conditions either in a straight line or in a curve.

A further objective is to provide a relatively light portable roller dynamometer that can be conveniently transported to a test location.

In view of the above objects, the present invention comprises in one aspect a roller dynamometer assembly for simulating road conditions for a vehicle having at least two drive wheels, of the type comprising: first and second roller assembly to rotationally support the left and right drive wheels of the manual vehicle, each roller assembly being associated with a dynamometer having means of roller speed and wheel torque sensors, characterized by: first and second carriages independently supporting said first and second roller assemblies, said first and second roller carriages each comprising a separate and separately transportable unit, not mechanically connected to the other unit; the carriage support means for supporting at least said first and second carriages on a substrate independently of said other first and second carriages, wherein said at least one carriage can be removed on the substrate in a lateral direction to the elongated shaft of said vehicle and said substrate, while supporting said vehicle; and each trolley supporting a dynamometer, each dynamometer embedded to a corresponding roller to apply a load to said corresponding roller where the road conditions are simulated on a vehicle built into said apparatus.

The carriage support means, which preferably comprises the roller means such as an array of linear bearings, allows a lateral movement (relative to the vehicle) independent of the carriages on a hard, level surface, such as a concrete floor. This allows adjustment of the carriage spacing to accommodate different vehicles (allowing the use of relatively compact rollers) and centering rollers by themselves on the wheels of the vehicle when the device is in use. The left and right roller hand carts can be positioned independently on a support surface, and not be joined to each other by any fixed mechanical joint. This provides transportation and placement.

The rollers may also have a stepped portion at each opposite end to serve as a wheel and steering wheel brake.

In addition, the apparatus conveniently incorporates a rotary assembly to support and mount each dynamometer to corresponding carriages for limited rotational movement relative to said carriage.

The rotary assembly preferably comprises first and second concentric members, such as a disc and a bolt bearing arrangement, embedded to said dynamometer and carriage respectively for relative rotation to each other.

In one version, the dynamometers are in communication with a control device, the control device receives information on wheel speed and torque from each of the dynamometers. The control device includes the processing means for comparing the differences in speed of rotation between the first and second dynamometers, and the torque control means for controlling the torque applied in at least one and preferably in both dynamometers to equalize substantially the respective rotation speeds for each mentioned roller.

The control means directs a faster spinning dynamometer to apply a greater amount of power absorption to its corresponding roller, relative to the slower torque dynamometer.

The control device may include the total energy absorption calculation means, where the total energy absorbed between all the dynamometers is calculated as a function of the mass of the vehicle, the speed and acceleration of each roll, and a value associated with the aerodynamic and frictional losses of the vehicle and friction losses inside the dynamometers.

In one version, the torque control means also allows the control of one or both dynamometers to apply an unequal speed of controlled rotation of the respective rollers to simulate a driving condition in a curve.

In another aspect, the invention comprises a roller dynamometer assembly for vehicle testing to simulate road conditions for a vehicle, of the type comprising: at least one roller mounted on a frame for supporting and contacting, in a rotational manner , with a vehicle wheel; a dynamometer coupled to the roller to apply a load to the roller with which the road conditions are simulated on the vehicle coupled to the apparatus; characterized by: a rotary assembly for coupling and supporting the dynamometer on the frame for rotational movement Regarding the frame, the rotary assembly comprises the first and second concentric members coupled to said dynamometer and carriage, respectively.

The rotary assembly is conveniently of the type previously described. In addition, the apparatus is conveniently provided with rollers to have contact with the driving wheels of the test vehicle.

In a further aspect, the invention comprises a roller dynamometer for simulating the road conditions for a vehicle having at least two drive wheels, of the type comprising: first and second roller dynamometer assemblies for an independent coupling with the corresponding drive wheels, each roller dynamometer assembly comprises at least one roller coupled to a corresponding dynamometer, the first and second dynamometer assemblies for the independent rotation of the respective rollers, relative to each one, and each one has a speed of rotation and detection means, and energy absorption means; and characterized by: a control unit for receiving the information of rotation speed and torque from said dynamometers and having a logic circuit for comparing and measuring any difference in speed and controlling one, and preferably, both dynamometers in response to two differences The control device of the logic circuit controls the energy absorption means of the first and second dynamometers to perform the driving simulation, either in a straight line or in a curve.

The control device conveniently includes the total energy absorption calculation means, wherein the total energy absorbed among all the dynamometers is calculated as a function of the mass of the vehicle, the speed and acceleration of each roll, and an associated value with the aerodynamics and friction losses of the vehicle, and the frictional losses inside the dynamometer.

In a further aspect, the invention comprises a method for simulating road conditions for a vehicle of the type, comprising the steps of: providing the first and second independent roller dynamometer assemblies, each associated with the torque and speed sensors of rotation, the first and second assemblies are associated with a control device for receiving the speed and torque information from each dynamometer assembly and independently controls the resistance applied thereby; supporting, at least, two drive wheels of the vehicle on the corresponding first and second roller dynamometer assemblies; drive the drive wheels with the test vehicle; independently measuring the speed and torque of the two driving wheels; characterized by: independently controlling, at least one, and, preferably, both roller dynamometer assemblies to control the speed of rotation thereof to selectively simulate the vehicle traveling in either a straight or a curved line.

An additional step may comprise the measurement of the total energy output of the vehicle with an algorithm that calculates the total energy absorption of the dynamometer, where the total energy absorption between all the dynamometers is calculated as a function of the mass of the vehicle, the speed and acceleration of each roller, and a value associated with the aerodynamics and frictional losses of the vehicle and frictional losses within the dynamometer.

The rollers preferably comprise, in any of the above devices and methods, a general hourglass configuration for the self-centering of the wheels of the vehicle.

The present invention will now be described in the manner of a detailed description and illustration of the specific examples.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of one embodiment of the present invention, Figure 2 is a side elevational view of a portion of the apparatus as shown in Figure 1; Figure 2a is an end elevation view of Figure 1; Figure 3 is a plan view of an individual roller unit for use in accordance with the present invention; Figure 4 is a plan view of a further embodiment of a roller carriage; Figure 5 is a side view of Figure 4; Figure 6 is a perspective view of the apparatus in use; and Figure 7 is a block diagram showing the operation of the invention.

Similar numeration in the drawings denotes similar elements.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figures 1 and 2, the apparatus 10 includes the first and second identical carriages 24, one of which is illustrated here. In use, the respective carriages are placed under the left and right drive wheels when a vehicle is coupled to be tested with the device. Each car supports the individual rollers, described below, to be coupled with the wheels of the vehicle, and the dynamometers are adjusted with the rollers. The carts are conveniently placed on a hard, level, flat surface. Each carriage can move laterally (relative to the vehicle) on the surface by means of a roller associated with each carriage, such as in a linear support system 30 (shown in Figure 2) on the bottom surface of the carriages. The roller means further allows the carriages to roll laterally, while supporting the vehicle, to accommodate the self-centering of the carriage rollers.

Referring to Figures 3-5, each carriage 24 comprises a generally rectangular carriage frame 32 composed of the side members 34 of the frame, the members 36 of the end of the frame, being completely divided into two parts by a pair of members 40 and 42. cross sections of the frame to form the first and second rectangular portions 32a and 32b of the carriage. The first portion 32a of the carriage supports the rollers, described below, and the second portion 32b of the carriage supports the dynamometer, described below. The end and transverse members 36 and '40 of the frame of the first portion 32a of the carriage, each supporting a pair of shaft bearings 50 for rotatably supporting the rollers 54. The roller axes 56, associated with each of the rollers, are supported rotationally within the shaft bearings. The end and transverse members 36 and 42 of the second portion 32b of the carriage support the assembly 60 of the dynamometer, to rotationally mount a dynamometer 46 on the carriage. The dynamometer and the mounts will be described below in more detail.

The first portion 32a of the carriage supports a pair of rollers 54 spaced apart in parallel orientation to rotatably support and engage a drive wheel of a vehicle.

In one version, one of the rollers 54, of the pair, is coupled to a dynamometer. The other roller rotates freely. Thus, each car supports a single dynamometer, comprising an energy absorption unit ("PAU") associated with a single driving wheel of the vehicle. It will be seen that with the modification, the rollers can be varied in size to accommodate pairs of drive wheels of the type found in trucks and buses.

The dynamometer assemblies 60 each comprise a disc 62 flexibly mounted to the portion 32b of the carriage to engage a corresponding front end 64 of the dynamometer 46. A circular system of bearing cartridges 66 are mounted on each front end of the dynamometer, and are rotatably coupled to the flexible disk, which includes a recessed crown 68 comprising a raceway.

A flange bushing of a strong metal comprises first and second arms 70, 72 extending from the dynamometer and the carriage member 32b, respectively. A sturdy metal rim 74 connects the respective arms and limits the rotation of the dynamometer relative to the carriage. The ridge of a strong metal comprises a transducer to convert the torque between the dynamometer and the car into electrical current.

In a further embodiment, shown in Figures 3 and 4, the carriages 24 each comprise the frame members 80 forming a rectangular configuration for supporting the rollers. A dynamometer support member 82 comprises a member, generally similar to a plate, which extends from a transverse member of the frame outwards, from the center of the apparatus. Each dynamometer holder has a bearing 84 that extends upwards to rotatably engage and support the dynamometer 86. Each roller 54 is releasably engaged to a corresponding dynamometer by means of a releasable coupling 90. A ridge of a strong metal, not shown, which joins the dynamometer with the dynamometer support, limits the rotational movement of each dynamometer and makes it possible to ensure the measurement of the rotational forces acting on the dynamometer.

Referring to rollers 54, which are shown more particularly in Figure 5, each of the rollers includes a portion 67 stepped up at each respective end serving as a steering wheel and as a brake to minimize the risk that a wheel of the vehicle will decoupling the roller.

Each roller 54 has an hourglass shape, generally. And it comprises a central axis, with the body of the roller diverging from the midpoint, generally, of central axis, at an angle of about 170 ° to around 179 ° 59 ', relative to the longitudinal axis of the roller.

It was found that this arrangement facilitates the safe placement and improves the centering of a wheel alone on the roller, without exceeding the wear of the rim. The lateral movement of the rollers, in response to the centering movement by itself, is accommodated by the rotary movement of the carriage on the substrate allowed by the linear bearings.

Figure 6 illustrates the arrangement of the apparatus 10 under the front (motor) wheels of a vehicle 100 (shown in dotted line). In the arrangement shown, the vehicle under test comprises a front wheel drive vehicle. The apparatus can be easily adapted for use with motorcycles and other single-wheel drive vehicles, rear wheel drive vehicles or four-wheel drive vehicles, or other drive arrangements, by means of adaptation or repositioning of the unit and / or provision of additional units to be coupled with the corresponding drive wheels of the vehicle.

Each dynamometer includes the means of measuring the rotation speed, such as an internal optical position reader (referred to below), to measure the rotational position of the dynamometer axis. The data of the optical reader is transmitted to the central control device described below, which calculates the speed of rotation of the dynamometer and of the corresponding roller.

Each dynamometer is attached to the central control unit 200, which will now be described with reference to FIG. 7. The control unit allows the individual dynamometers, left and right, to apply a load substantially and exactly equal to the corresponding wheels to simulate the conditions of handling in a straight line. Alternatively, a controlled uneven load can be applied to simulate the vehicle by driving around a curve.

The electrical signals from the transducers 202, associated with the flanges 74 of resistant metal torque indicators, may comprise amplitude or variable frequency signals. These signals, together with the signals of the optical position reader 204, are transmitted to the control device. The control device receives separately the Speed and torque information from each corresponding roller unit. In a straight-line driving simulation, all the rollers must turn at the same speed. Since there is no mechanical connection to transmit the rotation movement between the roller units corresponding to the corresponding sides of the vehicle, a logical connection is created by the control device to allow the control device to control the transducer to maintain identical speeds . In compliance, the control device includes a comparator circuit 206 for evaluating any difference in speed between the respective dynamometers. If any speed difference is detected, this information is transmitted to the logic circuit 207, which, in turn, controls the left and right motor control circuits 208 associated with each dynamometer, which, in turn, increases or decreases, as can be the case, the load applied by the respective dynamometer.

Logic circuit 207 may include software that applies an energy distribution algorithm based on the difference in roller speed to control the respective diameters. The control algorithm calculates a Appropriate control signal such that more of the energy absorbed will be changed to the faster spinning rollers, with more load applied by the corresponding dynamometer, to make it slower. The dynamometer attached to the slower roll will be required to absorb less energy, allowing the corresponding roller to accelerate. A logical circuit of energy output of the vehicle, which can be managed by means of the software, will calculate the total energy absorbed among all the rollers, based on the following: a) the mass of the vehicle; b) roller acceleration in real time; c) the roller speed and the roller load to be simulated, the latter based on the known aerodynamics of the vehicle and the friction loss factors; d) friction losses inside the dynamometer to compensate; and e) the force output of the vehicle.

A display 212 displays the vehicle's simulated speed, the return radius and the energy output.

The examples given above identify a dynamometer of the electric motor type; it will be seen that any appropriate UAP can be used.

It will be further seen that the apparatus and method have been described with reference to the vehicle having at least two drive wheels, aspects of the invention that can be quickly adapted for use with a vehicle having a single drive wheel, such as a motorcycle. .

Although the present invention has been described in the manner of a preferred embodiment, it will be seen that numerous deviations and variations can be made to the invention without departing from the spirit and approach of the invention as defined in the claims.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (15)

REI VINDICACIONES

1. A roller dynamometer vehicle test assembly for simulating road conditions for a vehicle having at least two drive wheels, of the type that is supported on a floor surface and comprises first and second roller assemblies for supporting In a rotary way the vehicle wheels of the left and right side on the roller cylinders, each roller assembly is associated with a separate dynamometer having a means of roller speed sensor and wheel torque, each of said assembly The roller can be moved independently in the direction of the axis on said floor surface, characterized in that: the first and second roller carriage frames independently support the corresponding first and second roller assemblies, directly on said floor surface; the sliding means of the carriage associated with at least one of said carriage frames to allow at least one frame, already mentioned of carriage, to roll on said substrate independently of the other of said carriage frames in a direction that is axia-1 in relation to roller cylinders, while said vehicle is supported; said sliding means for allowing said carriage to move on said substrate along a single axis in the absence of the guiding means joining said carriage frames; each carriage supports a dynamometer, each dynamometer is coupled to a corresponding roller cylinder to apply a load to said corresponding roller where the road conditions are simulated on a vehicle coupled with said apparatus; and the wheel centering means associated with each roller assembly for automatically centering said vehicle wheels on said roller cylinders during the testing of said vehicle by placing said roller carriage frames on said substrate.

2 . The apparatus as defined in claim 1, characterized in that said carriage sliding means comprises a system of linear supports mounted on each of said carriages and are capable of allowing said carriage to be rolled laterally relative to the axis of said vehicle. , while it is supported on a hard and solid surface.

3. The apparatus as defined in claim 1, characterized in that there is a second additional roller support means associated with a second of said carriage frames for lateral movement on said substrate while said carriage supports. said vehicle.

4. The apparatus as defined in claim 1, characterized in that said wheel centering means each comprise an elongate body, generally cylindrical, having opposite ends and a middle region, said body having, in general, a clock shape. of sand, wherein the middle region has a narrow central diameter relative to the opposite ends of said body to support a vehicle wheel in said narrower region.

5. The apparatus as defined in claim 1, characterized in that said roller cylinders each comprise a generally cylindrical body, having opposite ends, and having a stepped portion upwards, at each of said opposite ends, having a diameter, wherein the diameter of said stepped portion is greater than the diameter of said roller cylinder immediately adjacent said portion.

6. The apparatus as defined in claim 5, characterized in that said stepped portion comprises a flywheel.

7. The apparatus as defined in claim 1, characterized in that a rotary assembly is additionally incorporated to mount, at least, one of said dynamometers for a limited rotary movement, relative to said carriage.

8. The apparatus as defined in claim 7, characterized in that said rotary assembly comprises first and second concentric members coupled to said carriage dynamometer, respectively, for relative rotation to each other.

9. The apparatus as defined in claim 8, characterized in that said first member comprises a disk and said second member comprises the disk coupling means.

10. The apparatus as defined in claim 9, characterized in that said disc coupling means comprises a bolt support system.

11. The apparatus as defined in claim 1, characterized in that said dynamometers are in communication with a control device, said control device receives the information of the speed of the wheel and the torque from each of said dynamometers, and has the means of processing for comparing the differences in speed of rotation between said first and second dynamometers and the torque control means for controlling the torque applied by, at least one of said dynamometers to substantially equal the respective speeds of rotation of said rollers.

12. The apparatus as defined in claim 11, characterized in that said control device includes the means of calculating the total absorption energy, wherein the total absorption energy between all the dynamometers is calculated as a function of the mass of the vehicle, the speed and acceleration of each roller cylinder, and a value associated with aerodynamics and friction losses of the vehicle and friction losses within the dynamometers.

13. The apparatus as defined in claim 11, characterized in that said torque control means additionally allows the control of said dynamometers to selectively apply a controlled rotation speed, equal or unequal, to the respective roller cylinders to selectively simulate, either a vehicle path in a straight line or in a curve.

14. A roll dynamometer as claimed in claim 13, characterized in that said dynamometer assembly includes, each, the torque detection means and the rotation speed and the energy absorption means, said control unit for receiving the information of the speed of rotation and touch from said dynamometers having a logic circuit to compare and measure any difference in speed between said dynamometers and control at least one of said dynamometers in response to said speed deferences, said The control device of the logic circuit is provided with the control means of the energy absorption means of at least one dynamometer mentioned for selectively simulating, either a vehicle path in a straight line or in a curve.

15. A method for simulating road conditions for a vehicle, of the type comprising the steps of: a) providing first and second roller dynamometer assemblies, each having torque and rotational speed sensors, and a command device for receiving torque and speed information from each dynamometer assembly, and independently control the resistance applied by these; b) providing a test vehicle having at least two drive wheels; c) supporting at least two mentioned driving wheels on the corresponding first and second roller dynamometer assemblies; d) driving, at least, two driven wheels mentioned with said test vehicle; e) independently measure the speed and torque of, at least, two mentioned driving wheels; Y f) independently controlling, with said control device, at least one of said first and second roll dynamometer assemblies for controlling the speed of rotation thereof, characterized in that: the first and second dynamometer assemblies are controlled to selectively simulate , be it the trajectory of the vehicle in a straight line or in a curve.