FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10; rule 13]
TITLE: “A REAR UNDERRUN PROTECTION SYSTEM FOR A VEHICLE AND A
METHOD THEREOF”
Name and Address of the Applicant: TATA MOTORS LIMITED; Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India.
Nationality: Indian
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.

TECHNICAL FIELD
Present disclosure generally relates to the field of automobiles. Particularly, but not exclusively, the present disclosure relates to a rear under run protective system employed in automobiles such as commercial vehicles and a method for operating the system.
BACKGROUND OF THE DISCLOSURE
Commercial vehicles such as trucks, tippers, semi-trucks etc., include an underrun protective device (UPD) at various locations to prevent underrun during an accident. Usually, these UPD’s are installed in the sides, and rear end as a guard or a protection device. The rear underrun protective device (RUPD) absorbs significant amount of impact energy during rear-end collisions and also prevent other vehicles from getting under the chassis or wheels of the vehicle. Usually, such RUPD’s are employed in commercial vehicles that have high ground clearance. Thereby prevents serious injuries to the occupants during accidents. Conventionally, RUPD is usually in the form of a longitudinal beam which is attached to a rear end of the vehicle via frame members or arms in a traverse direction. These arms may be rotatable such that the RUPD can be raised above the ground.
Generally, RUPD’s tend to contact the road surface during travel of the vehicle on a gradient which bends the RUPD and causes damage. Also, due to irregular ground surfaces and undulations during travel of the vehicle, the RUPD may repeatedly contact the ground surface and hence it is subjected to scraping or damage. This damage to the RUPD does not serve the intended purpose of preventing the underruns and hence fail to fully absorb the impact or prevent vehicle going under the vehicle upon collisions. To overcome this damage to RUPD, several conventional actuating mechanisms are provided to lift the RUPD above the ground surface. These actuators may be manually or automatically operated. These actuators may be linear actuators or rotary actuators coupled to the frame members and are operated by a user. This operation of the actuators occurs without any feedback such as the gradient or a distance of the RUPD from the ground surface. Further, an actuation signal must be given by the user through an actuation switch. This requires a driver or a skilled operator to pay attention to the status of the RUPD which may distract the driver while driving the vehicle.
The present disclosure is directed to overcome one or more limitations stated above or other such limitations associated with the prior art.

SUMMARY OF THE DISCLOSURE
One or more shortcomings of conventional systems are overcome, and additional advantages are provided through a method and a system as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered as a part of the claimed disclosure.
In one non-limiting embodiment of the disclosure, a system for protecting a rear underrun protective device (RUPD) of a vehicle is disclosed. The system comprises of at least one guard bar. At least one connector having a first end is connected to the at least one guard bar and a second end coupled to the chassis. At least one actuator is coupled to the at least one connector at the first end to pivot the at least one connector about an axis A-A. Further, a control unit is communicatively coupled to the at least one actuator and is configured to receive a first signal from a gradient sensor associated with the vehicle corresponding to a gradient angle of a surface. Receive a second signal from a sensor associated with the chassis corresponding to a distance between the at least one guard bar and the surface. Compare the gradient angle and the distance with a predetermined data and generate an actuation signal based on the comparison. Lastly, the control unit is configured to actuate the at least one connector to operate the at least one connector about the axis A-A to displace the at least one guard bar from a first position to a second position.
In an embodiment of the disclosure, the first end of at least one connector is defined with a provision to receive a coupling member for pivotal movement of the at least one connector to displace the at least one guard bar.
In an embodiment of the disclosure, the at least one actuator is a linear actuator configured to pivotally displace the at least one connector.
In an embodiment of the disclosure, the gradient angle is determined by the gradient sensor based on a position of the vehicle plying over the surface and the distance is measured by the sensor based on the distance of the chassis with respect to the surface.
In an embodiment of the disclosure, wherein the gradient sensor and the sensor are at least one of an angle sensor, a proximity sensor, potentiometer, distance measurement sensor.

In an embodiment of the disclosure, the distance is determined by a sensor mounted on the chassis at a front-end of the chassis and at a rear end of the vehicle.
In an embodiment of the disclosure, the first position of the at least one guard bar is an active position, when the RUPD is parallel to the road surface and the second position of the RUPD corresponds to an actuated position achieved upon pivotable movement of the at least one connector about an axis A-A.
In an embodiment of the disclosure, the control unit generates an actuation signal to displace the RUPD to the second position when the gradient angle (x) is equal to or less than 10° and the vertical distance is equal to or less than 100 mm.
In an embodiment of the disclosure, the control unit deactivates the at least one actuator to retract the RUPD from the second position to the first position if at least one of the gradient angle and the vertical distance overlaps with the predetermined data.
In another non-limiting embodiment of the disclosure, a method for operation of a rear underrun protective system of a vehicle is disclosed. The method comprises of receiving, by a control unit, a first signal corresponding to a gradient angle of the vehicle from a gradient sensor associated with the vehicle. Receiving, by the control unit, a second signal corresponding to a distance between the at least one guard bar and a surface from a sensor connected to a chassis of the vehicle. Comparing, by the control unit, the gradient angle and the distance with a predetermined data. Generating, by the control unit an actuation signal to drive an at least one actuator connected to the chassis of the vehicle, the at least one actuator is coupled to at least one connector which is in turn connected to the at least one guard bar. Actuating, by the control unit, the at least one actuator to operate the at least one connector to displace the at least one guard bar from a first position to a second position if the determined gradient angle and the distance is less than the predetermined data. The method also includes deactivating, by the control unit, the actuator to retract the at least one guard bar from the second position to the first position if the gradient angle and the distance overlaps with the predetermined data.
It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:
Figs. 1a and 1b is a perspective view and side view of a rear underrun protective system of a vehicle in accordance with an embodiment of the present disclosure.
Fig. 2 is an exploded view of a rear underrun protective system of a vehicle in accordance with an embodiment of the present disclosure.
Fig. 3 is a schematic layout of the rear underrun protective system, in accordance with an embodiment of the present disclosure;
Fig. 4 illustrates a flow chart showing preconditions to activate the system of fig. 3;
Fig. 5 is a side view depicting a gradient angle and a distance with respect to a surface;
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the figure and will be described below. It should be understood, however, that it is not intended to limit the

disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of the method and the system, without departing from the scope of the disclosure. Therefore, such modifications are considered to be part of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skilled in the art having benefit of the description herein. Also, the method of the present disclosure may be employed in variety of vehicles having different specification.
The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that of a system that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, method, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
Embodiments of the present disclosure relates to a rear underrun protective system to prevent and protect damage to a rear underrun protective device (RUPD) of a vehicle. Generally, RUPD’s equipped in vehicles tend to contact the ground surface due to irregularities, undulations etc. In some scenarios, the RUPD may also contact a ground surface when the vehicle is traversing on a gradient which may damage the RUPD. This damage to the RUPD does not serve the intended purpose of preventing the underruns. Faulty RUPD’s fail to fully absorb the impact during collisions and may cause serious injuries. Conventionally, the RUPD is actuated by actuators which are manually operated by a user or a driver. This requires attention by the user and may distract the user while driving the vehicle which is undesired. Further, frequent replacement of the damaged RUPD also increases maintenance cost.
In view of this, embodiments of the present disclosure disclose a system for protecting rear underrun protective device (RUPD) of a vehicle and a method thereof. The system comprises of at least one guard bar connected to a chassis of the vehicle. At least one connector having a first end is connected to the at least one guard bar and a second end coupled to the chassis. At

least one actuator is coupled to the at least one connector at the first end to pivot the at least one connector about an axis A-A. Further, a control unit is communicatively coupled to the at least one actuator and is configured to receive a first signal from a gradient sensor associated with the vehicle corresponding to a gradient angle of a surface. The control unit receives a second signal from a sensor associated with the chassis corresponding to a distance between the at least one guard bar and the surface. Further, the control unit is configured to compare the gradient angle and the distance with a predetermined data and generate an actuation signal based on the comparison. Lastly, the control unit is configured to actuate the at least one actuator to operate the at least one connector about the axis A-A to displace the at least one guard bar from a first position to a second position.
Further, the present disclosure also discloses a method for operating a rear underrun protective system of a vehicle is disclosed. The method includes the steps of receiving a first signal by a control unit corresponding to a gradient angle of the vehicle from a gradient sensor associated with the vehicle. Then a second signal corresponding to a distance between at least one guard bar and a surface is received by the control unit, from a sensor connected to a chassis of the vehicle. Later, the values of gradient angle and the distance are compared by the control unit with a predetermined data. Followed by generating an actuation signal to drive an at least one actuator connected to the chassis of the vehicle. Further, the at least one connector is actuated by the control unit, through the at least one actuator to displace the at least one guard bar from a first position to a second position if the determined gradient angle and the distance overlaps with the predetermined data. Lastly, the control unit deactivates the at least one actuator to retract the at least one guard bar from the second position to the first position if the gradient angle and the distance is overlaps with the predetermined data.
The following paragraphs describe the present disclosure with reference to Figs. 1a to 5. In the figures, the same element or elements which have similar functions are indicated by the same reference signs.
Fig. 1a illustrates a rear underrun protective system (1) for a vehicle. The RUPD (1) comprises at least one guard bar (1) and at least one connector (8) coupled to the at least one guard bar (9). The at least one guard bar (9) is connected to a chassis of the vehicle via the at least one connector (8). The at least one guard bar (9) is connected below the chassis (12) at a rear end of the vehicle. However, the same shall not be considered as limitation since the at least one guard bar (9) can be fixed anywhere on the vehicle where there is requirement. In an

embodiment, the at least one guard bar (9) may be connected at a front end or at sides of the vehicle based on the requirement. The at least one connector (8) is defined with a first end connected to the at least one guard bar (9) and a second end is coupled to the chassis (12). The first end of the at least one connector (8) is defined with a provision (16) to receive a coupling member (30). In an embodiment, the provision (16) may be defined in a hollow cylindrical shape, rectangular or square shape based on the requirement and the shape of the coupling member (30). The coupling member (30) is defined with a cylinder with a first flange (31) and a second flange (32) extending radially from both ends of the cylinder. The at least one first flange (31) is configured to support the first end of the at least one connector (8) on the chassis (12). The at least one second flange (32) is defined with a first plurality of holes (not shown) that match with a second plurality of holes (not shown) defined on the chassis (12). The at least one second flange (32) is fastened to the chassis (12) using suitable fastening means. The at least one connector (8) is pivotable about and axis A-A and the coupling member (3) and supports the pivotal movement of the at least one connector (8). The at least one connector (8) includes a projection (11) with a slot extending from its outer circumference at the first end. An at least one actuator (2) is coupled to the at least one connector (8) about the slot by a fastener. In an embodiment, the at least one actuator (2) may be a linear actuator coupled to the at least one connector (8) for pivotal movement of the at least one connector (8) about the axis A-A to displace the at least one guard bar (9) from a first position to a second position. However, this cannot be considered as a limitation and various types of actuators may be used for driving the at least one connector (1). The linear actuator comprises a motor and a piston connected to the motor. The rotating motion of the motor is converted to linear displacement of the piston within a cylinder in a controlled manner. In an exemplary embodiment, at least two connectors (8) are coupled to the at least one guard bar (9) at either ends of the chassis (12) and are connected to two separate actuators (2) to displace the at least one guard bar (9). However, the at least one guard bar (9) may be displaced by using a single connector (8) connected at a central portion of the chassis (12) and the at least one actuator (2) for displacement. Further, at least one support bracket is fixed to the chassis to arrest the movement of the at least one guard bar (9) in the first position. The first position of the at least one guard bar (9) is considered to be in an active position, when the at least one guard bar (9) is parallel to the ground surface. The second position of the at least one guard bar (9) corresponds to an actuated position when the pivotable movement of the at least one connector (8) displaces the at least one guard bar (9) about the axis A-A. In an embodiment, the first position is also defined as the rest position or a position at which the at least one guard bar (9) is parallel to the ground

surface. In an embodiment, the second position of the at least one guard bar (9) corresponds to a lifted position achieved upon pivotable movement of the pair of at least one connector (8) about the axis A-A. The at least one connector (8) is perpendicular to the chassis (12) in the first position such that the at least one guard bar (9) is in active state to prevent underruns during an accident or collision. The at least one connector (8) may be angularly oriented about the axis A-A in the second position of the at least one guard bar (9). Further, a gradient sensor (4) and a sensor (6) are installed on the chassis (12) proximal to the centre of gravity of the vehicle to detect a gradient angle (x) and a distance (a) between the ground surface and the chassis (12) of the vehicle respectively.
Referring to Fig. 3 which is a schematic layout of the system (100), the system (100) further comprises a control unit (10) to determine condition of the vehicle. In an embodiment, the condition of the vehicle may be as follows. In an ON condition, wherein, the engine of the vehicle is running. A second condition of the vehicle may be in OFF condition. However, this may not be considered as a limitation since any other vehicle condition such as an electric motor ON condition or electric motor OFF condition can also be sensed by the control unit (10). Further, the gradient sensor (4) is installed on the chassis (12) and near the centre of gravity of the vehicle to detect the gradient angle (x) based on position of the vehicle on a ground surface the vehicle is plying on. The sensor (6) is installed on the chassis (12) to detect a distance (a) between the surface and the chassis (12) of the vehicle. The control unit (10) is configured to receive the signals from the gradient sensor and the sensor (6) to determine the gradient angle (x) of the surface and the distance (a). In an embodiment, the control unit (10) derives the value of a distance (y) between the surface and the at least one guard bar (9) from the determined distance (a) value. In an embodiment, gradient sensor (4) and the sensor (6) are at least one of an angle sensor, a proximity sensor, potentiometer, distance measurement sensor. The control unit (10) compares the values of the gradient angle (x) and the distance (a) with a predefined value and drives the at least one actuator (2) to displace the at least one guard bar (9). The control unit (10) drives the at least one actuator (2) to displace the at least one guard bar (9) from the first position to the second position if the determined value is less than the predefined value. In an embodiment, the predefined value of the gradient angle (x) may be equal to or less than 10°and the vertical distance (a) may be equal to or less than 100 mm. In an embodiment, the gradient angle (x) alone is considered for actuation of the at least one guard bar (9) and however this cannot be considered as a limitation and the distance (a) alone or both the values may be considered for actuation. The control unit (10) drives the at least one actuator

(2) to retract the at least one guard bar (9) into the first position after the gradient is crossed by the vehicle or the distance (a) is at the predefined value.
Fig. 4 is a flow diagram depicting preconditions for operating the at least one guard bar (9) of the rear underrun protective system (100). The gradient angle (x) and the distance (a) are continuously detected by the gradient sensor (4) and the sensor (6) respectively. The detected values of the gradient angle (x) and the distance (a) are transmitted as signals to the control unit (10) which analyses the received data. Further, the control unit (10) compares the determined values of the gradient angle (x) and the distance (a) with predefined values. In an exemplary embodiment, if the value of the gradient angle (x) is less than the predefined value, the control unit (10) drives the at least one actuator (2) to actuate the at least one guard bar (9) to the second position. Alternatively, if the value of the gradient angle (x) is more than the predefined value, the control unit (10) drives the at least one actuator (2) to retract the at least one guard bar (9) from the second position into the first position. Similarly, if the distance (a) is found to be lesser than the predefined value, the control unit (10) sends a signal to drive the at least one actuator (2) to actuate the at least one guard bar (9) to the second position. If the distance (a) is equal to the predefined value, the at least one guard bar (9) is retracted into the first position. In an embodiment, the predefined values of the gradient angle (x) is equal to or less than 10° and the distance (a) is equal to or less than 100 mm.
In an embodiment, the at least one guard bar (9) is actuatable by the distance (z) and however this cannot be considered as a limitation, and this actuated distance (z) may varies by making the structural modifications of the rear underrun protective system (100). In an embodiment, the gradient angle (x) is considered from a point of contact of a tyre to the surface to the at least one guard bar (9) as shown in Fig. 5.
As an example, if the vehicle is travelling on a gradient or a slope surface, the at least one guard bar (9) in the active position tends to contact the ground surface. At this point, the gradient angle (x) between the vehicle body and the road surface tends to vary, such that the at least one guide bar (9) contacts the ground surface. This condition is sensed by the gradient sensor (4) and the corresponding signal will be sent to the control unit (10) such that the at least one guide bar (9) is displaced away from the surface in the second position if the gradient angle (x) is lesser than the predefined value. In an embodiment, this change in gradient angle (x) may also be caused during pitching of the vehicle which is the movement of the vehicle with respect to the traverse axis of the vehicle.

In yet another example, when the vehicle is travelling on a flat ground surface, the at least one guard bar (9) will be in the active position such that the impact of the collisions and underruns which may occur at the rear end of the vehicle are fully absorbed by the at least one guard bar (9). When a vehicle is travelling on uneven roads, the vehicle tends to move with respect to its longitudinal axis which is generally referred as a roll movement. During rolling, suspension dynamics of the vehicle tend to vary, and this may reduce the distance (a) between the surface and the chassis (12). This condition is sensed by the sensor (6) and the corresponding signal will be sent to the control unit (10) such that the at least one guide bar (9) is displaced away from the surface in the second position if the distance (a) is lesser than the predefined value. In an embodiment, this change in distance (a) may also be caused by improper or heavy loading of the vehicle and wheels getting stuck in loose or muddy areas. In an embodiment, the variation in the distance (a) may also occur during the yaw movement of the vehicle which is a movement with respect to vertical axis of the vehicle.
In an embodiment, the gradient angle (x) and the distance (a) are continuously monitored by the control unit (10) for dynamically operating the at least one guide bar (9) without any human intervention.
In an embodiment, the system (100) can be adopted or installed in any existing vehicle or trucks to protect the rear underrun protective device (RUPD).
In an embodiment, the RUPD is protected throughout the vehicle travel and also during pitch, roll and yaw movement of the vehicle in real time. Thereby prevents frequent maintenance and replacement of the RUPD and reduces cost of the system (100).
In an embodiment of the disclosure, the control unit (10) or electronic control unit may be a centralized control unit, or a dedicated control unit associated with the vehicle. The control unit (10) may be implemented by any computing systems that is utilized to implement the features of the present disclosure. The control unit may be comprised of a processing unit. The processing unit may comprise at least one data processor for executing program components for executing user- or system-generated requests. The processing unit may be a specialized processing unit such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc. The processing unit may include a microprocessor, such as AMD Athlon, Duron or Opteron,

ARM’s application, embedded or secure processors, IBM PowerPC, Intel’s Core, Itanium, Xeon, Celeron or other line of processors, etc. The processing unit may be implemented using a mainframe, distributed processor, multi-core, parallel, grid, or other architectures. Some embodiments may utilize embedded technologies like application-specific integrated circuits (ASICs), digital signal processors (DSPs), Field Programmable Gate Arrays (FPGAs), etc.
In some embodiments, the ECU may be disposed in communication with one or more memory devices (e.g., RAM, ROM etc.) via a storage interface. The storage interface may connect to memory devices including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as serial advanced technology attachment (SATA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), fiber channel, small computing system interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, redundant array of independent discs (RAID), solid-state memory devices, solid-state drives, etc.
It is to be understood that a person of ordinary skill in the art may develop a system of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.
Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent

is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (108) having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (108) having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
Referral Numerals:

System 100

Method 200
Rear underrun protective device (RUPD) 1
Actuator 2
Gradient sensor 4
Gradient angle x
sensor 6
Distance a, y, z
At least one connector 8
At least one guard bar 9
Control unit 10
Projection 11
Chassis 12
Provision 16
Support bracket 20
Coupling member 30
At least one first flange 31
At least one second flange 32

WE CLAIM:
1. A rear underrun protection system (100) for a vehicle, the system (100) comprising:
at least one guard bar (9);
at least one connector (8), having a first end connectable to the at least one guard bar (9) and a second end is coupled to the chassis (12);
at least one actuator (2) coupled to the at least one connector (8) at the first end to pivot the at least one connector (8) about an axis (A-A); and
a control unit (10) communicatively coupled to the at least one actuator (2), the control unit (10) is configured to:
receive a first signal from a gradient sensor (4) associated with the vehicle corresponding to a gradient angle (x) of a surface;
receive a second signal from a sensor (6) associated with the chassis (12) corresponding to a distance (a) between the at least one guard bar (9) and the surface;
compare the gradient angle (x) and the distance (a) with a predetermined data;
generate an actuation signal based on the comparison and actuate the at least one actuator (2) to operate the at least one connector (8) about the axis A-A to displace the g at least one guard bar (9) from a first position to a second position.
2. The system (100) as claimed in claim 1, wherein the first end of the at least one connector (8) is defined with a provision (16) to receive a coupling member (30) for pivotal movement of the at least one connector (8) to displace the at least one guard bar (9).
3. The system (100) as claimed in claim 1, wherein the at least one actuator (2) is a linear actuator is configured to pivotally displace the connector (8).
4. The system (100) as claimed in claim 1, wherein the gradient angle (x) is determined by the gradient sensor (4) based on a position of the vehicle plying over the surface and the distance (a) is measured by the sensor (6) based on the distance of the chassis with respect to the surface.

5. The system (100) as claimed in claim 1, wherein the gradient sensor (4) and the sensor (6) are at least one of an angle sensor, a proximity sensor, potentiometer, distance measurement sensor.
6. The system (100) as claimed in claim 1, wherein the distance (a) is determined by a sensor (6) mounted on the chassis (12) at a front end of the chassis (12) and at a rear end of the vehicle.
7. The system (100) as claimed in claim 1, wherein the first position of the at least one guard bar (9) is an active position, when the at least one guard bar (9) is parallel to the road surface and the second position of the at least one guard bar (9) corresponds to an actuated position achieved upon pivotable movement of the at least one connector (8) about an axis A-A.
8. The system (100) as claimed in claim 1, wherein the control unit (10) generates an actuation signal to displace the at least one guard bar (9) to the second position when the gradient angle (x) is equal to or less than 10° and the vertical distance (a) is equal to or less than 100 mm.
9. The system (100) as claimed in claim 1, wherein the control unit (10) deactivates the actuator (2) to retract the at least one guard bar (9) from the second position to the first position if at least one of the gradient angle (x) and the vertical distance (a) overlaps with the predetermined data.
10. A method (200) for operation of a rear underrun protection system (100) of a vehicle, the method (100) comprising:
receiving, by a control unit (10), a first signal corresponding to a gradient angle (x) of the vehicle from a gradient sensor (4) associated with the vehicle;
receiving, by the control unit (10), a second signal corresponding to a distance (a) between at least one guard bar (9) and a surface from a sensor (6) connected to a chassis (12) of the vehicle;
comparing, by the control unit (10), the gradient angle (x) and the distance (a) with a predetermined data;
generating, by the control unit (10) an actuation signal to drive an at least one actuator (2) connected to the chassis (12) of the vehicle, the at least one actuator (2) is

coupled to a rear underrun protective device (1), the device (1) comprises at least one connector (8) which is in turn connected to the at least one guard bar (9);
actuating, by the control unit (10), the at least one actuator to operate the at least one connector (8) to displace the at least one guard bar (9) from a first position to a second position, if the determined gradient angle (x) and the distance (a) is less than the predetermined data; and
deactivating, by the control unit (10), the at least one actuator (2) to retract the at least one guard bar (9) from the second position to the first position if the gradient angle (x) and the distance (a) overlaps with the predetermined data.