Claims:
1. An apparatus for testing a sensor (4) for real-time application, the apparatus comprising:
a cantilever arm (2) having a housing at free end(2a) for adapting the sensor (4) to be tested;
at least one motor (3) mounted at the cantilever arm (2); the motor (3) configured to provide multi-axis vibrations;
a rotating means (5) adapted at a predetermined distance from the sensor (4);
at least one control unit (11,12) configured to control the speed variation of the rotation means (5) and the speed, position and orientation of the motor (3) to achieve the predetermined vibration levels subjected to the sensor (4) in three axes (X, Y, Z) for real-time testing of the sensor and obtaining the output of the sensor (4) thereof.
2. The apparatus as claimed in claim 1, wherein the apparatus comprises an accelerometer sensor (10) positioned over the sensor (4) or at the cantilever arm (2) said accelerometer is connected to the control unit to measure the vibration amplitude levels and provides feedback to the control unit.

3. The apparatus as claimed in claim 1, wherein the motor (3) is slideably mounted at the cantilever arm (2).

4. The apparatus as claimed in claim 1, wherein the apparatus comprises an adjustable mounting screw (13) connected with the motor (3) for altering and locking the axis of rotation of the motor (3).

5. The apparatus as claimed in claim 1, wherein the motor (3) allows attaching an eccentric mass of predetermined weight.

6. The apparatus as claimed in claim 1, wherein the cantilever arm (2) comprises means for attaching an additional motor to generate combined vibration effects for testing sensors.

7. An apparatus for testing a sensor (4) for real-time application, the apparatus comprising:
a sliding means (14) connected with a beam (8);
a support arm (9) connected with the beam (8), the support arm (9) having a housing for adapting a rotating means (5);
at least one motor (6) mounted at the support arm (9), the motor (6) is connected with the rotating means shaft to adapt one or more rotating means of predetermined size;
a driving motor (7) coupled with the sliding means (14) for moving the beam (8) in an axial direction;
a housing on the support arm for adapting a sensor (4) at a predetermined distance from the rotating means (5) for testing the sensor (4) under air gap variation;
at least one control unit (11,12) connected with the motor (6) and the driving motor (7) to control the air gap between the sensor (4) and the rotating means (5) in accordance with the predetermined speed of the rotating means (5) and its position with respect to the sensor(4) and obtaining the output of the sensor (4) thereof.

8. The apparatus as claimed in claim 9, wherein the air gap variation between the sensor (4) and the rotating means (5) is achieved by controlling the driving motor (7) by a control unit (12).

9. The apparatus as claimed in claim 1 or claim 7, wherein the predetermined distance between the sensor (4) and the rotating means (5) ranges between 0.5mm to 5 mm.

10. A method for testing a sensor for real-time application, the method comprising the steps of
placing a sensor (4) on a cantilever arm (2) for testing;
positioning a motor (3) at the cantilever arm (2) to produce vibrations;
configuring a control unit (11) to control the speed, position and orientation of the motor (3) to achieve the predetermined vibration levels subjected to the sensor (4) in three axes (X, Y, Z) for real-time testing of the sensor; and
obtaining the output of the sensor (4).

11. A method for testing a sensor (4) for real-time application, the method comprising the steps of
positioning a rotating means (5) on a support arm (9) connected with a sliding means (14);
placing a sensor (4) in front of the rotating means (5) for testing air gap variation of the sensor (4);
moving the sliding means (14) to vary the air gap between the rotating means (5) and the sensor (4);

configuring a control system control the air gap between the sensor (4) and the rotating means (5) in accordance with the predetermined speed of the rotating means (5) and its position with respect to the sensor (4); and
obtaining the output of the sensor (4).
, Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10, Rule 13]

AN APPARATUS AND A METHOD FOR TESTING A SENSOR FOR REAL-TIME APPLICATION

MAHINDRA & MAHINDRA LIMITED, A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT, 1913, HAVING ADDRESS AT MAHINDRA & MAHINDRA LIMITED, MAHINDRA RESEARCH VALLEY, MAHINDRA WORLD CITY, PLOT NO.41/1, ANJUR P.O., CHENGALPATTU, KANCHIPURAM DISTRICT, TAMILNADU – 603004, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE INVENTION
The present invention relates to an apparatus and a method for testing a sensor for real-time application.
BACKGROUND
Sensors are the devices used for detecting the change or variation in the conditions wherein the sensors are deployed. Due to their vast utility and reliability, sensors have become an imperative component of many systems. Also, due to increasing dominance of embedded systems in the industry and majorly the automotive and aerospace, sensors have become integral parts of the embedded world.
Many of the sensors used for detecting speed, proximity for various applications are Magnetic Reluctance based or Hall effect-based sensors. Primarily, these sensors detect the variation in the air gap within their functional range.
Before placing the sensor into the systems, it is essentially required to check the quality parameters of the functional range of the sensors. It is well known to test the functionality of the sensors via an apparatus by simulating the operating conditions in which sensor will be subjected for their real-time application. For example, if a sensor is to be placed in an engine, the sensor is required to be tested by the apparatus or device by simulating the operating conditions of the engine.
It has been observed that in real-time application, the sensors are subjected to high levels of vibrations in automotive applications which are quite higher than the vibrations produced by the apparatus while testing. When this vehicle is an off-road vehicle, then the vibration levels generated are immense and thus cannot be simulated by existing devices.
It has also been observed that there is a huge difference in the amplitudes of vibrations and the axis of vibration generation between the simulated vibrations produced by the apparatus and the vibrations produced during real time applications of the sensors. Thus, the parameters of vibrations and air gap variation of these tested sensors lacks precision.
There are existing prior art devices which provides a vibrating motor mounted over a shock isolated base and a cushion socket to create vibrations whereas the cushion socket is equipped with the driving device for driving vibration mechanism to rotate and a driving device is interfaced using an elastic buffer with a shaft arrangement. However, it has been observed that the existing testing devices or apparatus have limitations in terms of testing the sensors while simulating the multi-dimensional vibrations. Further, due to the designs and configuration of the existing testing devices, they have been found to be complex in operation and having limited operating ranges.
It is also well known to use Piezoelectric diaphragm or a transducer that produces vibrations on to a platform while testing the vibrations. Piezoelectric vibrations create vibrations on a platform, however, the use of the same has been observed that the magnitude of vibrations generated by these devices is very less. Also, piezoelectric transducers have limitations in producing vibrations in multiple axes.
It has also been observed that existing testing devices due to their configuration have limitations in conducting vibration testing and air gap variation simultaneously as when one operation is being conducted i.e. vibration test, the other operation i.e. air gap variation remains stationary.
Furthermore, in assessing the expected life span of a sensor, the testing is an essential factor which requires the apparatus to test the sensor effectively for real-time application.
Therefore, the sensor of the present invention is to solve one or more of the aforesaid issues.
OBJECT OF THE INVENTION
The primary objective of the present invention is to provide an apparatus for testing a sensor for real-time application which is capable of testing the sensors in multi-dimensional vibrations/ along with eccentric mass.
Another objective of the present invention is to provide an apparatus for testing a sensor for real-time application capable of testing the sensors for air gap variation.
Another objective of the present invention is to provide an apparatus for testing a sensor for real-time application simultaneously for testing vibration and air gap variation of the sensor.
Another objective of the present invention is to provide an apparatus for testing a sensor by simulating the speed, air gap variations and multi axis vibrations to which the sensor will be subjected in real-time application.
One another sensor of the present invention is to provide an apparatus which is advantageously simple, efficient, highly cost-effective, multifunctional and universally for testing a sensor for real-time application.
SUMMARY OF THE INVENTION
In accordance with the present invention, an apparatus for testing a sensor for real-time application is provided. The apparatus comprises: a cantilever arm having a housing for adapting the sensor to be tested; a motor slideably mounted at the cantilever arm to provide multi-axis vibrations. The Apparatus comprises a rotating means adapted at a predetermined distance from the sensor and a control unit configured to control the speed variation of the rotation means and the speed, position and orientation of the motor to achieve the predetermined vibration levels subjected to the sensor in all three axes (X, Y, Z) for real-time testing of the sensor and obtaining the output of the sensor thereof.
In accordance with the present invention, the apparatus comprises an accelerometer sensor positioned over the sensor or at the cantilever arm; said accelerometer is connected to the control unit to measure the vibration amplitude levels and provides feedback to the control unit. The apparatus comprises an adjustable mounting screw connected with the motor for altering and locking the axis of rotation of the motor.
In accordance with the present invention, the cantilever arm comprises means for attaching an additional motor to generate combined vibration effects for testing sensors.
In accordance with another embodiment, an apparatus for testing a sensor for real-time application is provided. The apparatus comprises a sliding means connected with a beam; a support arm connected with the beam. The support arm is having a housing for adapting a rotating means. The apparatus comprises a motor mounted at the support arm whereas the motor is connected with the rotating means shaft. The rotating means shaft is adaptable to receive one or more rotating means of a predetermined size. The testing apparatus comprises a driving motor coupled with the sliding means for moving the beam in an axial direction and a housing on the support arm for adapting a sensor at a predetermined distance from the rotating means for testing the sensor under air gap variation. The apparatus comprises a control unit connected with the motor and the driving motor to control the air gap between the sensor and the rotating means in accordance with the predetermined speed of the rotating means and its position with respect to the sensor and obtaining the output of the sensor thereof. The air gap variation between the sensor and the rotating means is achieved by controlling a driving motor by a control unit.
In accordance with another embodiment of the present invention, a method for testing a sensor for real-time application is provided. The method comprising the steps of placing a sensor on a cantilever arm for testing; positioning a motor at a cantilever arm to produce vibrations; configuring a control unit to control the speed, position and orientation of the motor to achieve the predetermined vibration levels subjected to the sensor in three axes (X, Y, Z) for real-time testing of the sensor; and obtaining the output of the sensor.
In accordance with another embodiment of the present invention, a method for testing a sensor for real-time application is provided. The method comprising the steps of positioning a rotating means on a support arm connected with a sliding means; placing a sensor in front of the rotating means for testing air gap variation of a sensor; moving the sliding means to vary the air gap between the rotating means and the sensor; configuring a control system control the air gap between the sensor and the rotating means in accordance with the predetermined speed of the rotating means and its position with respect to the sensor; and obtaining the output of the sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made to embodiments of the invention which may be illustrated in the accompanying figure(s). These figure(s) are intended to be illustrative and not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
FIG. 1 is an isometric view of general assembly of essential components of an apparatus for testing sensors in accordance with an embodiment of the present invention.
FIG. 2A, 2B shows the sub assembly of essential components of the apparatus for testing sensors in accordance with an embodiment of the present invention.
FIG. 3 is an exploded view of the assembly of the apparatus in accordance with an embodiment of the present invention.
FIG. 4 shows a perspective view of essential components of the apparatus in accordance with an embodiment of the present invention.
FIG. 5 shows the orientation of the vibration motor in X direction in accordance with an embodiment of the present invention.
FIG. 6 shows the orientation of the vibration motor in Y direction in accordance with an embodiment of the present invention.
FIG. 7 shows the orientation of the vibration motor in Z direction in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The subject matter is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It may be evident; however, that such matter can be practiced with these specific details. In other instances, well-known structures as shown in diagram form in order to facilitate describing the invention.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.
Fig. 1 shows an isometric view of general assembly of essential components of the apparatus in accordance with an embodiment of the present invention. The apparatus comprises a stationary pole (1) for holding a cantilever arm (2) having a housing at free end (2a) for adapting a sensor (4) to be tested. The apparatus comprises one motor (3) slideably mounted at the cantilever arm (2). The motor (3) is configured to provide multi axis vibrations. A rotating means (5) is adapted at a predetermined distance from the sensor (4). The apparatus comprises a control system configured to control the speed variation of the rotation means and the speed, position and orientation of the motor (3 to achieve the predetermined vibration levels subjected to the sensor (4) in three axes (X, Y, Z) for real-time testing of the sensor and obtaining the output of the sensor thereof. The apparatus comprises an accelerometer sensor (10) positioned over the sensor (4) or the cantilever arm (2) to measure the vibration amplitude levels and provide feedback to the control system. The control system comprises a control unit (11) connected with the accelerometer sensor (10) and the motor (3). The accelerometer sensor measures the vibration amplitude levels of the sensor (4) and provides the feedback to the control unit (11).The simulated vibration amplitude levels received from the accelerometer sensor are fed to the control unit (11) which is configured to control the Speed, Position and Orientation of the Vibration motor to achieve the desired vibration levels. The motor (3) is slideably movable on the axis of the cantilever arm in order to increase or decrease the amplitude of vibrations to be subjected to the sensor adapted on the free end of the cantilever arm. The motor (3) includes housing for attaching an eccentric mass of different predetermined weight as required by user for increasing or varying the vibration levels. The apparatus comprises an adjustable mounting screw (13) connected with the motor (3) for altering the axis of rotation of the motor (3). The adjustable mounting screw (13) locks the orientation of the motor (3) during testing of the sensor.The cantilever arm (2) of the apparatus comprises means for attaching an additional motor to generate combined vibration effects for testing sensors. The apparatus comprises a sliding means (14) connected with a beam (8). A support arm (9) is connected with the beam (8). The support arm (9) is having a housing for adapting a gear (5). A motor (6) is mounted at the support arm whereas the motor is connected with a gear shaft. A driving motor (7) is coupled with the sliding means (14) for moving the beam (8) in an axial direction. The apparatus comprises a sensor adapted adjacent to the gear for testing. The apparatus comprises a control system configured to control an air gap between the sensor and the gear (5) in accordance with the predetermined speed of the gear (5) and its position with respect to the sensor and obtaining the output of the sensor thereof. The control system comprises a control unit (12) connected with the motor (6) and the driving motor (7). According to the present invention, the air gap variation between the sensor (4) and the gear (5) is achieved by controlling the driving motor (7) via. a control unit (12).
In accordance with a non-limiting embodiment of the present invention, the rotating means (5) is a gear having predetermined number of teeth required to test the sensor by the apparatus.
In accordance with an advantageous embodiment of the present invention, the apparatus includes a configuration in which the sensor (4) to be tested and the rotating means / gear (5) are interchangeable. Accordingly, the housing of the cantilever arm (2) is adaptable to receive the gear (5) and the housing of the support arm is adaptable to receive the sensor (4) to be tested.
In accordance with an embodiment of the present invention, the predetermined air gap between the sensor to be tested and the rotating means generally ranges between 0.5 mm to 5 mm depending upon the size, variety and application of the sensor.
In accordance with an embodiment of the present invention, the stationary pole (1) holds and adjusts the height of the cantilever arm (2) in accordance with the size of the sensor (5) to be tested. A screwed wing nut mechanism is used to link the first beam and the cantilever arm. The height of the cantilever arm may be adjusted by adjusting the wing nut.
FIG. 2A shows the sub assembly of essential components of the apparatus in accordance with an embodiment of the present invention. Fig. 2A shows the configuration of the assembly of the apparatus for testing the sensor against the predetermined level of vibrations produced by the motor (3) attached at the cantilever arm (2). The cantilever arm (2) comprises means for attaching an additional motor to generate combined vibration effects for testing sensors. The apparatus comprises an adjustable mounting screw (13) which is fixedly attached with the mounting enclosure of the motor (3). The shape of the mounting enclosure is rectangular which assist the user in sliding the motor (3) or changing the orientation of the motor. The adjustable mounting screw also locks the orientation of the motor. The sensor (4) is placed at the free end of the cantilever beam (2). Frequency of vibration subjected to the sensor is changed by altering the input voltage to the motor (3).
In accordance with an embodiment of the present invention, the shape of the cantilever arm may be but not limited to rectangular and circular shape.
In accordance with an embodiment of the present invention, the cantilever arm is printed with the amplitude levels of vibrations for each position of sliding the motor which assists the user in varying the amplitude levels of the vibrations.
According to an embodiment of the present invention, the sensor to be tested is a sensor, or a device that needs to be subjected to vibration test. The sensors may be but not limited to magnetic sensor or Hall Effect based sensor.
Fig. 2B shows the sub assembly of essential components of the apparatus in accordance with an embodiment of the present invention. Fig. 2B shows the configuration of the assembly of the apparatus for testing the sensor for air gap variation. The apparatus comprises a beam connected with the sliding means (14). The sliding means (14) is a guide rail arrangement. The support arm (9) is attached to the beam (8). The support arm (9) comprises a housing for adapting a gear (5). A motor (6) is mounted at the support arm whereas the motor is connected with a gear shaft. The driving motor (7) is coupled with the sliding means (13) for moving the beam (8) in an axial direction. The motor (6) rotates the gear (5). The speed variation of the gear (5) is achieved by controlling the motor (6) via. the control unit (12). The air gap variation between the sensor (4) and the gear (5) is achieved by controlling the driving motor (7), which is controlled via a control system. The gear (5) is adaptable to mount gears of different dimensions which increase the scope or utility of the apparatus.
According to the present invention, the gear includes predetermined number of teeth as required by the user.
FIG. 3 is an exploded view of the assembly of the apparatus for testing sensors in accordance with an embodiment of the present invention. The components of the testing devices can be assembled with ease. The apparatus allows the user to conduct simultaneously the vibration test along with the air gap variation.
FIG. 4 shows a perspective view of essential components of the assembly of apparatus in accordance with an embodiment of the present invention. The apparatus comprises a cantilever arm (2) having a housing at free end (2a) for a sensor (4) to be tested. The apparatus comprises one motor (3) eccentrically mounted on the cantilever arm (2). The motor (3) is configured to provide multi axis vibrations. A gear (5) is adapted adjacent to the sensor (4). The apparatus comprises an accelerometer sensor (10) positioned over the sensor (4) or the cantilever arm (2) to measure the vibration amplitude levels and provide feedback to a control system of the apparatus. The motor (3) is slideably connected at the cantilever arm. The motor (3) is movable on the longitudinal axis of the cantilever arm in order to increase or decrease the amplitude of vibrations to be subjected to the sensor adapted on the free end of the cantilever arm. The apparatus comprises an adjustable mounting screw (13) connected with the motor (3) for altering the axis of rotation of the motor (3). The adjustable mounting screw (13) locks the orientation of the motor (3) during testing of the sensor. A sliding means (14) is connected with the beam (8). A support arm (9) is connected with the beam (8). The support arm (9) is having a housing for adapting a gear (5). A motor (6) is mounted at the support arm whereas the motor is connected with a gear shaft. A driving motor (7) is coupled with the sliding means (14) for moving the beam (8) in an axial direction. The apparatus comprises a control system having a control unit (11) connected with the accelerometer sensor (10) and the motor (3). The control system is configured to control the speed variation of the rotation means and the speed, position and orientation of the motor (3) to achieve the predetermined vibration levels subjected to the sensor (4) in three axis (X, Y, Z) for real-time testing of the sensor and obtaining the output of the sensor thereof. The control system further comprises a control unit (12) connected with the motor (6) and the driving motor (7) wherein the control system is also configured to control an air gap between the sensor and the gear (5) in accordance with the predetermined speed of the gear (5) and its position with respect to the sensor and obtaining the output of the sensor thereof. The air gap variation between the sensor (4) and the gear (5) is achieved by controlling a driving motor (7) via. a control unit (12). The control system having control units (11, 12) is configured to perform and control simultaneously the vibration testing and the air gap variation of the sensors.
According to an embodiment of the present invention, the said control units (11, 12), can be combined or integrated into a single electronic control unit (ECU).
According to the present invention, the housing(s) of the cantilever arm and the support arm are adaptable to receive the sensor and the gear respectively or vice versa.
FIG. 5 shows the orientation of the vibration motor in X direction in accordance with an embodiment of the present invention. The motor is mounted to the cantilever arm using a flexible adjustable screwed linkage which enables the user in changing the orientation of the motor. The tilting of motor in X direction produces vibrations along the cantilever arm in X-axis. The frequency of the motor is varied by altering the input voltage of the vibration motor.
FIG. 6 shows the orientation of the vibration motor in Y direction in accordance with an embodiment of the present invention. The motor is mounted to the cantilever arm using a flexible adjustable screwed linkage which enables the user in changing the orientation of the motor. The tilting of motor in Y direction produces vibrations along the cantilever arm in Y-axis.
FIG. 7 shows the orientation of the vibration motor in Z direction in accordance with an embodiment of the present invention. The motor is mounted to the cantilever arm using a flexible adjustable screwed linkage which enables the user in changing the orientation of the motor. The tilting of motor in Z direction produces vibrations along the cantilever arm in Z-axis.
In accordance with an embodiment of the present invention, the apparatus comprises a single motor which will be oriented according to the axis in which vibration needs to be generated. Additionally, if required, the apparatus is adaptable to mount three different motors in three different directions i.e. X, Y and Z.
According to an embodiment of the present invention, the control system is configured to control the input power to the vibration motor. The motor power can be predefined which will eventually automate the system. The power source to the system can be AC / DC wherein it will help in making the setup portable. The control system may comprise a memory unit to store the vibration and air gap variation data for each sensor to be tested by the apparatus.
In accordance with another embodiment, the present invention provides a method for testing a sensor using the present apparatus. The method comprises the steps of: (a) placing a sensor (4) on a cantilever arm (2) for testing; (b) positioning a motor (3) at a cantilever arm to produce vibrations; (c) configuring a control unit (11) to control the speed, position and orientation of the motor (3) to achieve the predetermined vibration levels subjected to the sensor (4) in three axes (X, Y, Z) for real-time testing of the sensor; and (d) obtaining the output of the sensor (4).
In accordance with another embodiment, a method for testing a sensor for real-time application using the present apparatus is provided. The method comprising the steps of (a) positioning a rotating means (5) on a support arm (9) connected with a sliding means (14); (b) placing a sensor (4) in front of the rotating means (5) for testing the air gap variation of the sensor (4); (c) moving the sliding means (14) to vary the air gap between the rotating means (5) and the sensor (4); (d) configuring a control system control the air gap between the sensor (4) and the rotating means in accordance with the predetermined speed of the gear and its position with respect to the sensor (4); and (e) obtaining the output of the sensor (4).
ADVANTAGES OF THE INVENTION
Below are the technical advantages of the present invention: -
• The present invention can be used to simulate real-time Vibration for sensor validation, like Magnetic / Hall sensor validation methods. It provides a vibrational platform that consists of an eccentrically loaded mass motor to produce longitudinal and transverse vibrations.
• This apparatus is universal to its application which may conduct testing of a sensor or a sensor under test that is prone to a vibrational environment, create vibration using the proposed technique for multiple applications (like acoustics) etc., For example, a Magnetic/Hall sensor which finds its application on Vehicles and Engines, is subjected to a multi axial vibration during its operation. During its design and testing phases, the user simulates real time possible vibration to enhance the efficiency of the sensor.
• The present invention provides a multi-axial vibrational platform by simulating the degrees of vibration the actual sensor or sensor would undergo.
• The present invention provides a platform for testing simultaneously the multi axis vibration testing and air gap variation of the sensor to be tested.

The embodiments of the invention shown and discussed herein are merely illustrative of modes of application of the present invention. Reference to details in this discussion is not intended to limit the scope of the claims to these details, or to the figures used to illustrate the invention.

LIST OF REFERENCE NUMERALS
1- Stationary Pole
2- Cantilever Arm
3- Motor
4- Sensor
5- Rotating means / Gear
6- Motor
7- Driving Motor
8- Beam
9- Support Arm
10- Accelerometer Sensor
11- Control Unit
12- Control Unit
13- Adjustable Mounting Screw
14- Sliding Means