WO2011080757A2

WO2011080757A2 - Method for aligning and positioning a module mounted on a vehicle

Info

Publication number: WO2011080757A2
Application number: PCT/IN2010/000856
Authority: WO
Inventors: Kishore Kumar Venkataswamy
Original assignee: The Tata Power Company Ltd.
Priority date: 2009-12-29
Filing date: 2010-12-27
Publication date: 2011-07-07
Also published as: WO2011080757A3

Abstract

A method for aligning and positioning a module mounted on a vehicle is provided in accordance with the present invention. Modules requiring azimuth and elevation position accuracy need to be aligned to be relatively horizontal (true to earth) for efficient operation. The method in accordance with this invention achieves this by providing an adaptor, typically a substantially flat plate element, on a vehicle frame for mounting the module. The vehicle frame is first aligned true to earth using a screw jack and an electronic sensor is calibrated with reference to the vehicle frame. Then the adaptor is aligned such that it is also true to earth. The module is fitted and locked on the leveled adapted plate. Hydraulic jacks are provided to adjust the vehicle frame and accordingly the adaptor to align true to earth irrespective of the type of terrain the vehicle is located on.

Description

METHOD FOR ALIGNING AND POSITIONING A MODULE MOUNTED ON A VEHICLE

FIELD OF THE INVENTION

This invention relates to aligning and positioning systems. BACKGROUND

Sensitivity of certain equipment / modules relate to the accuracy with which it is maintained stable when subjected to azimuth and elevation movements. Maintaining accuracy of position when there is a change in position of the equipment / module from a pre-determined equilibrium state is a challenge faced during the operation of such modules. Sensitivity in terms of output is of crucial importance in cases where the module is subjected to high payloads resulting in deflection for varied azimuth and elevation movement.

The operation of equipment wherein sensitivity and efficient output is critical, the accuracy of output is predominantly attributed to the manner in which it is mounted for its operation based on pre-determined specifications on uneven terrain. The test of a true mounting platform lies in how parallel and coplanar the mounting surface is with respect to the earth without affecting the accuracy of operation of the equipment.

The main factors that affect the operation of such equipment or any equipment which deal with high loads are maintaining the center of gravity, true to earth alignment, repeatability, stability and rigidity at various angular movements. Modules need a parallel and coplanar mounting platform for accurate operation which is hard to establish due to various manufacturing and assembly tolerances of all the parts that are assembled to form a mounting system for such modules. A cumulative of tolerances of a perfectly manufactured part will also result in a non coplanar and non parallel mount when such modules move over uneven terrain. Mounting assemblies known in the art require tremendous man power for operation with no guarantee of success or repeatability.

There is thus felt a need for a method for aligning and positioning such portable modules that overcomes the drawbacks of the methods known in the art.

OBJECTS OF THE INVENTION

An object of this invention is to provide a method for establishing and providing a horizontal (true to earth) and coplanar (with respect to ground) plane within 20 microns parallelity on a multi-axle vehicle.

Another object of this invention is to provide a method for rigidly aligning and positioning a module mounted on a vehicle during azimuth and elevation movements while transiting any kind of terrain.

Still another object of this invention is to provide a highly repeatable and easily achievable method for aligning and positioning a module mounted on a vehicle during azimuth and elevation movements. Yet another object of this invention is to provide a simple method for aligning and positioning a module mounted on a vehicle during azimuth and elevation movements.

An additional object of this invention is to provide a reliable method for aligning and positioning a module mounted on a vehicle during azimuth and elevation movements.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a method for aligning and positioning a module mounted on a vehicle, the module being in need of azimuth and elevation position accuracy and therefore requiring a relatively accurate horizontal (true to earth) alignment, the vehicle being fitted with a plurality of hydraulically operated jacks for the aligning and positioning,

the method comprising:

• a calibration step comprising:

o mounting a vehicle frame on the vehicle;

o providing an electronic level sensor on the vehicle frame;

o leveling the vehicle frame to be true to earth (trunnion axis); o calibrating the electronic level sensor to read zero with reference to the true to earth (trunnion axis) leveled vehicle frame;

o mounting a substantially flat adaptor at a pre-determined location on the vehicle frame; o leveling the adaptor with reference to the true to earth (trunnion axis) leveled vehicle frame;

o fitting the module on the adaptor; and

o leveling the module fitted adaptor with reference to the leveled vehicle frame post fitting; and

• an operative leveling step comprising:

o transporting the adaptor and module fitted vehicle to a location where the module is to be deployed; and

o leveling the vehicle frame with reference to the calibrated position of the adaptor using the hydraulically operated jacks and the electronic level sensor.

Preferably, in accordance with this invention, the step of leveling the vehicle frame includes the steps of:

using at least one mechanical screw jack such that the vehicle frame is aligned true to earth (trunnion axis); and

leveling a pitch surface of the vehicle frame using water tubes such that the vehicle frame and the vehicle are aligned true to earth (trunnion axis).

Additionally, in accordance with the present invention, the step of leveling the adaptor includes the steps of:

providing a spirit level for indicating the level of the adaptor; and using adjustable bushes for aligning the adaptor with reference to the trunnion axis.

Typically, in accordance with this invention, the step of fitting the module on the adaptor includes the steps of: using circular slots provided on the adaptor; and

locking the module in a desired position on the adaptor.

Typically, in accordance with this invention, the step of using water tubes comprises the steps of:

providing a plurality of water tubes co-operating with a trunnion axis; measuring the lower meniscus of water in the water tubes;

recording the difference in level of water in the water tubes; and operating the screw jack such that difference in level of water in the water tubes is reduced to zero.

Preferably, in accordance with this invention, the step of locking the module in a desired position on the adaptor comprises the step of providing guide pins that serve as reference for relocation of the module, in the event that it is removed for maintenance.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The invention will now be described in relation to the accompanying drawings, in which:

FIGURE 1 illustrates an adaptor in accordance with the present invention;

FIGURE 2 illustrates an arrangement of the adaptor of FIGURE 1 on a vehicle frame;

FIGURE 3 illustrates a plan view and a cross sectional side view of an arrangement of the adaptor of FIGURE 1 on a vehicle frame; and FIGURE 4 illustrates a plan view and a cross sectional view of a mounting arrangement of a module on the adaptor of FIGURE 1.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The invention will now be described with reference to the embodiments shown in the accompanying drawings. The embodiments do not limit the scope and ambit of the invention. The description relates purely to the exemplary preferred embodiments of the invention and its suggested applications.

The diagrams and the description hereto are merely illustrative and only exemplify the invention and in no way limit the scope thereof.

Sensitive modules mounted on vehicles, typically multi-axle vehicles, require accurate alignment for its operation during azimuth and elevation movements. Such modules are faced with the challenge of having mounting means plagued by manufacturing tolerances and assembly of parts leading eventually to errors in planes and subsequently the operation of the modules. In accordance with the present invention, a method for aligning and positioning of such modules is envisaged to overcome the drawbacks of the prior art. This method typically involves a step of calibration followed by an operative leveling step.

The method for aligning and positioning a module mounted on a vehicle in accordance with the present invention is explained herein below with reference to FIGURES 1-4, wherein, FIGURE 1 illustrates an adaptor in accordance with the present invention and is indicated generally by the numeral 100; FIGURE 2 illustrates an arrangement of the adaptor of FIGURE 1 on a vehicle frame and is indicated generally by the numeral 200; FIGURE 3 illustrates a plan view and a cross sectional side view of an arrangement of the adaptor of FIGURE 1 on a vehicle frame; and FIGURE 4 illustrates a plan view and a cross sectional view of a mounting arrangement of a module on the adaptor of FIGURE 1.

The main components of the mounting arrangement as illustrated in FIGURES 1-4 are referenced generally as given below: adaptor 10;

vehicle frame 12;

pad 14;

bushes 16 (12 sets);

springs and washers 18 (6 each);

esk screws 20 (6 Nos.);

grub screws 22 (6 Nos.);

module 24;

nuts 26 (4 Nos.);

guide pins 28 (2 Nos.); and

dowel pins 30 (4 Nos.).

A module 24 that needs azimuth and elevation position accuracy requires a relatively accurate horizontal (true to earth) alignment. When such a module 24 is mounted on a vehicle, it transits across all kinds of terrain. The vehicle is fitted with at least one hydraulically operated jack (not shown) for providing the required alignment. Preferably, in accordance with the present invention, four hydraulically operated jacks are provided.

Firstly, the vehicle frame 12 is mounted on the vehicle. An electronic level sensor (not shown) is mounted on the vehicle frame 12. The vehicle frame 12 is leveled such that it is aligned true to earth (trunnion axis). At least one mechanical screw jack is provided externally for this leveling procedure. A pitch surface of the vehicle frame 12 is also made zero using water tubes by adjusting the screw jack. The lower meniscus of water in the water tubes is measured and the difference in level of water in the water tubes is recorded. The screw jack is then operated such that the difference in level of water in the water tubes is reduced to zero.

The electronic level sensor is calibrated to read zero with reference to the vehicle frame 12 which has been aligned true to earth (trunnion axis). An adaptor 10, typically a substantially flat plate element, is mounted on the vehicle frame 12 at a pre-determined location using about 6 nos. spring washer 18, about 6 nos. csk screw 20. The adaptor 10 is then leveled with reference to the vehicle frame 12 which has been aligned true to earth (trunnion axis). 12 sets of adjustable bushes 16 are provided for this purpose and a spirit level is used for indicating the level of the adaptor 10. The module 24 is then fitted rigidly on the adaptor 10 using nuts 26. This adaptor 10 serves to be a mounting platform for the module 24 and hence is required to be maintained coplanar within approximately 20 micron parallelity and designed such that it stays even during any movement off a pre-determined equilibrium position for a pay load of approximately 18 tons. The module 24 is mounted on the leveled adaptor 10 using 4 nos. circular slots provided therein. The positional errors are computed for various angles during elevation movements. The module 24 is then adjusted to achieve a pre-determined accuracy level of say, approximately ± 5 sec. For this purpose the module 24 is rotated in a clockwise and anticlockwise (it creates angular movement of the module) direction, until the desired positional accuracy is achieved. With this alignment, a series of confirmatory checks are carried out to ensure precision and accuracy^The adjustment process is repeated till nearly perfect results are obtained and upon ensuring the same, the module 24 is locked.

Once the positional accuracy is met, the module 24 is locked to the adaptor 10 by using 2 Nos. guide pins 28 (diagonally opposite). Typically, split guide pins are used which are flexible at the core due to its geometry and material and very rigid at the surface. The guide pin hole is transferred to the adaptor 10 through the holes which are available in the module 24 for this purpose. The split guide pins with bushes counter the tilt while drilling guide pin holes. The guide pins 28 are provided, so that if the module 24 is removed for maintenance, it should get relocated in the same position as the calibration is done in that position. The positional accuracy is thus maintained in that position.

When the adaptor and module fitted vehicle transits different terrain to reach a location where the module 24 is to be deployed, four hydraulically operated jacks are used to level the vehicle frame with reference to the calibrated position of the adaptor 10. Thus the vehicle frame 12 and the adaptor 10 are made parallel and coplanar for various positions including yaw, pitch and roll. The module 24 is mounted on a platform, in the form of the adaptor 10, which is essentially aligned true to earth irrespective of the terrain on which the vehicle is located.

A Finite Element Analysis is carried out on the mounting arrangement to ensure perfectness of the design and ensure that the adaptor does not deflect upon loading.

TECHNICAL ADVANCEMENTS

The technical advancements offered by the present invention include the realization of:

• a method for establishing and providing a horizontal (true to earth) and coplanar (with respect to ground) plane within 20 microns parallelity on a multi-axle vehicle;

• a method for rigidly aligning and positioning a module mounted on a vehicle during azimuth and elevation movements while transiting any kind of terrain;

• a highly repeatable and easily achievable method for aligning and positioning a module mounted on a vehicle during azimuth and elevation movements;

• a simple method for aligning and positioning a module mounted on a vehicle during azimuth and elevation movements; and • a reliable method for aligning and positioning a module mounted on a vehicle during azimuth and elevation movements.

The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.

While considerable emphasis has been placed herein on the particular features of this invention, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiment without departing from the principles of the invention. These and other modifications in the nature of the invention or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Claims

Claims:

1. A method for aligning and positioning a module mounted on a vehicle, said module being in need of azimuth and elevation position accuracy and therefore requiring a relatively accurate horizontal (true to earth) alignment, the vehicle being fitted with a plurality of hydraulically operated jacks for said aligning and positioning, said method comprising:

• a calibration step comprising:

o mounting a vehicle frame on the vehicle;

o providing an electronic level sensor on the vehicle frame; o leveling the vehicle frame to be true to earth (trunnion axis);

o calibrating said electronic level sensor to read zero with reference to the true to earth (trunnion axis) leveled vehicle frame;

o mounting a substantially flat adaptor at a pre-determined location on the vehicle frame;

o leveling said adaptor with reference to the true to earth

(trunnion axis) leveled vehicle frame;

o fitting the module on said adaptor; and

o leveling said module fitted adaptor with reference to the leveled vehicle frame post fitting; and

• an operative leveling step comprising:

o transporting said adaptor and module fitted vehicle to a location where the module is to be deployed; and o leveling the vehicle frame with reference to the calibrated position of said adaptor using the hydraulically operated jacks and said electronic level sensor.

The method for aligning and positioning a module mounted on a vehicle as claimed in claim 1 , wherein the step of leveling the vehicle frame includes the steps of:

leveling a pitch surface of the vehicle frame using water tubes such that the vehicle frame and the vehicle are. aligned true to earth (trunnion axis).

The method for aligning and positioning a module mounted on a vehicle as claimed in claim 1 , wherein the step of leveling said adaptor includes the steps of :

providing a spirit level for indicating the level of said adaptor; and

using adjustable bushes for aligning said adaptor with reference to said trunnion axis.

The method for aligning and positioning a module mounted on a vehicle as claimed in claim 1, wherein the step of fitting the module on said adaptor includes the steps of:

using circular slots provided on said adaptor; and

locking the module in a desired position on said adaptor.

5. The method for aligning and positioning a module mounted on a vehicle as claimed in claim 2, wherein the step of using water tubes comprises the steps of:

providing a plurality of water tubes co-operating with a trunnion axis;

measuring the lower meniscus of water in said water tubes; recording the difference in level of water in said water tubes; and

operating the screw jack such that difference in level of water in said water tubes is reduced to zero.

6. The method for aligning and positioning a module mounted on a vehicle as claimed in claim 4, wherein the step of locking the module in a desired position on said adaptor comprises the step of providing guide pins that serve as reference for relocation of the module, in the event that it is removed for maintenance.