US20160097183A1

US20160097183A1 - System and method for monitoring position of machine implement

Info

Publication number: US20160097183A1
Application number: US14/506,915
Authority: US
Inventors: Karl A. Kirsch; Paul R. FRIEND
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2014-10-06
Filing date: 2014-10-06
Publication date: 2016-04-07

Abstract

A system for monitoring a position of an implement of a motor grader relative to a frame thereof is provided. The motor grader includes an actuation system to selectively move the implement relative to the frame. The system includes a fiber optic cable extending along at least a portion of the frame, a portion of the actuation system and a portion of the implement. The fiber optic cable is configured to move with the portion of the actuation system and the portion of the implement, and selectively generate signals indicative of a shape thereof. The system further includes a controller in communication with the fiber optic cable. The controller is configured to determine the shape of the fiber optic cable based on the signals received therefrom, and further determine a position of the implement relative to the frame based on the shape of the fiber optic cable.

Description

TECHNICAL FIELD

The current disclosure relates to an implement of a machine, and more particularly to a system and a method of monitoring a position of an implement of a motor grader.

BACKGROUND

A motor grader typically includes a front frame and a rear frame. An engine and a transmission system are disposed in the rear frame, while an operator cab is disposed in the front frame. The front frame also includes a beam to support an implement. A position and an orientation of the implement relative to the front frame are regulated by a drawbar, a circle member and multiple cylinders. The drawbar is supported on the beam, and moved in vertical and horizontal directions relative to the front frame via hydraulic cylinders. The circle member is attached to the drawbar. The circle member is allowed to rotate relative to the drawbar via a motor. The implement is coupled to the circle member through a retainer. Hydraulic cylinders further control linear movement and angular movement of the implement relative to the circle member. The position and orientation of the implement along with those of the various actuation elements, including the drawbar and the circle member, may have to be monitored for precise control of the implement.
U.S. Pat. No. 8,478,492 (the '492 patent) discloses a method and a system for performing non-contact based determination of the position of an implement. The '492 patent includes a non-contact based measurement system to determine the relative position of an implement coupled with a mobile machine. The geographic position of the mobile machine is determined based on a satellite based position determination system. The geographic position of the implement is determined based upon the geographic position of the mobile machine. Hence, the position of the implement is determined relative to the mobile machine.
Fiber optic shape sensing is known in the art. For example, a system for sensing fiber optic shape is disclosed in US Patent Publication Number 2013/0308138. The patent includes a fiber optic cable having one or more cores. An optical interrogation console generates reflection spectrum data indicative of a measurement of both amplitude and a phase of a reflection for each core as a function of wavelength. A 3D shape reconstructor reconstructs a 3D shape of the optical fiber.

SUMMARY OF THE DISCLOSURE

In one aspect of the current disclosure, a system for monitoring a position of an implement of a motor grader relative to a frame of the motor grader is provided. The motor grader includes an actuation system configured to selectively move the implement relative to the frame. The system includes a fiber optic cable extending along at least a portion of the frame, a portion of the actuation system and a portion of the implement. The fiber optic cable is configured to move with the portion of the actuation system and the portion of the implement. The fiber optic cable is further configured to selectively generate signals indicative of a shape thereof. The system further includes a controller in communication with the fiber optic cable. The controller is configured to determine the shape of the fiber optic cable based on the signals received therefrom. The controller is further configured to determine a position of the implement relative to the frame based on the shape of the fiber optic cable.
In another aspect of the current disclosure, a motor grader is provided. The motor grader includes a frame and an implement movable relative to the frame. The motor grader includes an actuation system coupled to the frame and the implement. The actuation system is configured to selectively move the implement relative to the frame. The motor grader further includes a fiber optic cable extending along at least a portion of the frame, a portion of the actuation system and a portion of the implement. The fiber optic cable is configured to move with the portion of the actuation system and the portion of the implement. The fiber optic cable is further configured to selectively generate signals indicative of a shape thereof. The motor grader further includes a controller in communication with the fiber optic cable. The controller is configured to determine the shape of the fiber optic cable based on the signals received therefrom. The controller is further configured to determine a position of the implement relative to the frame based on the shape of the fiber optic cable.
In yet another aspect of the current disclosure, a method of monitoring a position of an implement of a motor grader relative to a frame of the motor grader is provided. The motor grader includes an actuation system configured to selectively move the implement relative to the frame. The method includes providing a fiber optic cable along at least a portion of the frame, a portion of the actuation system and a portion of the implement. The fiber optic cable is configured to move with the portion of the actuation system and the portion of the implement. The method further includes receiving signals from the fiber optic cable. The signals are indicative of a shape of the fiber optic cable. The method also includes determining the shape of the fiber optic cable based on the received signals. The method further includes determining a position of the implement relative to the frame based on the shape of the fiber optic cable.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a motor grader, according to an aspect of the current disclosure;

FIG. 2 is a perspective view of an actuation system of the motor grader and a system for monitoring a position of an implement associated with the actuation system, according to an aspect of the current disclosure;

FIG. 3 is a sectional perspective view of a fiber optic cable of the system, according to an exemplary aspect of the current disclosure;

FIG. 4 is a perspective view of an arrangement of the fiber optic cable to determine a position of the implement, according to another aspect of the current disclosure;

FIG. 5 is a block diagram illustrating the system for determining the position of the implement, according to an aspect of the current disclosure;

FIG. 6 is an output of the system showing the position of the implement of FIG. 2, according to an aspect of the current disclosure;

FIG. 7 is an output of the system showing another position of the implement; and

FIG. 8 is a flowchart of a method of determining the position of the implement, according to an aspect of the current disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to specific aspects or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.
FIG. 1 shows a side view of a motor grader 100, according to an aspect of the current disclosure. The motor grader 100 may be used to level a surface of a ground. The motor grader 100 may include a frame. The frame may include a front frame 102 and a rear frame 104 coupled with the front frame 102. The front frame 102 may be pivotally coupled with the rear frame 104 such that the front frame 102 may rotate relative to the rear frame 104. In another aspect of the current disclosure, the motor grader 100 may include a single frame. The front frame 102 and the rear frame 104 may be supported on ground engaging members 107. The front frame 102 may include a beam 105 having a front end 111 coupled with the ground engaging members 107 and a rear end 109 pivotally coupled with the rear frame 104. In another aspect of the current disclosure, the ground engaging member 107 coupled with the front frame 102 may include an axle having both ends rotatably coupled with wheels. Similarly, the ground engaging members 107 coupled with the rear frame 104 may include one or more axles having both ends rotatably coupled with wheels. Alternatively, the ground engaging members 107 may be tracks.
The motor grader 100 may further include an implement 106 for performing various earth moving operations, such as ground levelling. The implement 106 may be disposed in the front frame 102. Specifically, the implement 106 may be supported on the beam 105. The implement 106 may include a blade 108 configured to be in contact with a surface of the ground. The motor grader 100 may further include a power source (not shown) to supply power to various components including, but not limited to, the ground engaging members 107 and the implement 106. In another aspect of the current disclosure, the power source may be an engine. The engine may be disposed in the rear frame 104. In another aspect of the current disclosure, the power source may include a battery, a fuel cell or any other electrical power storage device known in the art. The engine may drive the ground engaging members 107 via a transmission (not shown). The transmission may produce multiple output speed ratios or a continuously variable speed ratio between the engine and the ground engaging member 107. Further, an operator cab 110 may be supported on the front frame 102. The operator cab 110 may include various operator controls, along with displays or indicators used to drive the motor grader 100 and convey information to an operator.
FIG. 2 shows a perspective view of an actuation system 112 of the motor grader 100. The actuation system 112 may be configured to selectively move the implement 106 relative to the front frame 102. In another aspect of the current disclosure, a system 114 may be further associated with the actuation system 112 for monitoring a position of the implement 106. The actuation system 112 may include a drawbar member 120 movably coupled to the beam 105. The drawbar member 120 may include a first leg 122, a second leg 124 and a third leg 126. Ends of the first leg 122 and the second leg 124 may be connected to a bracket 127 disposed on the beam 105. The other ends of the first leg 122 and the second leg 124 may be connected proximate to a first end and a second end of the third leg 126, respectively. Thus, the drawbar 120 may define a tapered end 128 and a base end 130 distal from the tapered end 128. The tapered end 128 of the drawbar member 120 may be pivotally coupled to the front end 111 of the beam 105 via a joint, for example, a ball and socket joint. Hence, the drawbar member 120 may have multiple degrees of freedom of movement with respect to the front frame 102.
The drawbar 120 may include a yoke plate 158 adjacent to the base end 130. A circle member 160 may be rotatably coupled to the yoke plate 158. The circle member 160 may include an outer circumference 162 and an inner circumference 163. The circle member 160 may further include an arm portion 164 extending from the outer circumference 162. The arm portion 164 may extend towards the implement 106. Further, the arm portion 164 may be pivotally coupled to the implement 106. The circle member 160 may be further operatively coupled with a rotary actuator 161 (shown in FIG. 1). The rotary actuator 161 may be an electric motor or a hydraulic motor. The rotary actuator 161 may include a gear configured to engage with teeth (not shown) provided on the inner circumference 163 of the circle member 160. Further, the rotary actuator 161 may be mounted on the yoke plate 158 to engage with the circle member 160. The rotary actuator 161 may facilitate rotation of the circle member 160 about a first axis A1. Hence, the implement 106 may also be rotated about the first axis A1 substantially perpendicular to a plane of the yoke plate 158.
As shown in FIG. 2, the base end 130 of the drawbar member 120 may be coupled to the beam 105 via a support member 132. The support member 132 may be movably mounted on the beam 105. Further, the support member 132 may include a first lift arm 136 and a second lift arm 138. The first lift arm 136 and the second lift arm 138 may be pivotally coupled to the support member 132. Specifically, the first lift arm 136 may be pivotally coupled to one side of the beam 105 and the second lift arm 138 may be pivotally coupled to another side of the beam 105 opposite to the first lift arm 136. Each of the first and the second lift arms 136, 138 may include a leg 140 that may extend towards the drawbar member 120. A free end of the legs 140 may be coupled with a length adjusting member 142. The length adjusting member 142 may include a plurality of mounting holes 144 distributed along a length thereof. The free ends of the legs 140 may be coupled to any one of the mounting holes 144 in order to adjust a position of the first and second lift arms 136, 138.
A first linear actuator 146 may couple each of the first lift arm 136 and the second lift arm 138 to the base end 130 of the drawbar member 120. The first linear actuator 146 may be configured to move the drawbar member 120 along the first axis A1. In another aspect of the current disclosure, the first linear actuator 146 may be actuated by a hydraulic system (not shown) of the motor grader 100. The first linear actuator 146 may include a cylinder 152 and a piston rod 154 slidably disposed within the cylinder 152. The cylinder 152 may be coupled with the first lift arm 136 and the piston rod 154 may be coupled to the first end of the third leg 126. In another aspect of the current disclosure, the first linear actuator 146 may be a double acting cylinder. In such a case, a head end and a rod end of the cylinder 152 defined by the piston rod 154 may be in fluid communication with the hydraulic system. In another aspect of the current disclosure, the first linear actuator 146 may be a single acting cylinder. In such a case, the head end of the cylinder 152 may be in fluid communication with the hydraulic system.
In an exemplary aspect of the current disclosure, the hydraulic system of the motor grader 100 may include a pump (not shown) drivably coupled to the power source to supply pressurized fluid to the first linear actuator 146 from a fluid reservoir (not shown). The fluid reservoir may be disposed in the rear frame 104. The hydraulic system may further include one or more control valves to regulate supply of pressurized fluid to the first linear actuator 146. The control valves may be regulated by a controller 150 of the motor grader 100 based upon input signals from an operator controlled device. The first linear actuator 146 may be actuated by the hydraulic system to move the drawbar 120 upwards or downwards along the first axis A1. Hence, the implement 106 may also be moved along the first axis A1 with respect to the front frame 102.
The base end 130 of the drawbar member 120 may be further coupled to the support member 132 via a second linear actuator 156. The second linear actuator 156 may be configured to move the drawbar member 120 along a second axis A2 substantially perpendicular to the first axis A1. The second linear actuator 156 may be a hydraulic cylinder similar to the first linear actuator 146. One end of the second linear actuator 156 may be coupled to any one of the plurality of mounting holes 144 of the length adjusting member 142 and another end may be coupled adjacent to the second end of the third leg 126. The second linear actuator 156 may also be coupled to the hydraulic system similar to the first linear actuator 146. Thus, the second linear actuator 156 may be actuated to move the base end 130 along the second axis A2. Hence, the implement 106 may also be moved along the second axis A2 with respect to the front frame 102.
As shown in FIG. 2, the implement 106 includes the blade 108 and blade rails 103 coupled to the blade 108. The blade rails 103 may be further slidably coupled to a retainer 172. Further, the retainer 172 may be pivotally coupled to the arm portion 164 of the circle member 160. Further, the retainer 172 may be coupled to the circle member 160 via a third linear actuator 174. The third linear actuator 174 may be a hydraulic cylinder similar to the first linear actuator 146. One end of the third linear actuator 174 may be coupled to the retainer 172 and another end may be coupled to the circle member 160 to rotate the implement 106 relative to the arm portion 164 about the second axis A2. The third linear actuator 174 may also be coupled to the hydraulic system similar to the first linear actuator 146.
The actuation system 112 may further include a fourth linear actuator 180 received within the retainer 172. The fourth linear actuator 180 may be configured to slide the implement 106 relative to the retainer 172 along the second axis A2. The fourth linear actuator 180 may be a hydraulic cylinder similar to the first linear actuator 146. The fourth linear actuator 180 may include a cylinder 182 mounted on the retainer 172 and a piston rod 184 slidably disposed within the cylinder 182. The fourth linear actuator 180 may be coupled to the hydraulic system similar to the first linear actuator 146. Thus, the fourth linear actuator 180 may be actuated to linearly move the blade 108 along the second axis A2 relative to the retainer 172 and the arm portion 164.
As shown in FIG. 2, the system 114 may include a fiber optic cable 302. The fiber optic cable 302 may extend along at least a portion of the front frame 102, a portion of the actuation system 112 and a portion of the implement 106. Further, the fiber optic cable 302 may be configured to move with the portion of the actuation system 112 and the portion of the implement 106. The portions of the front frame 102, the actuation system 112 and the implement 106 are described hereinafter in detail. The fiber optic cable 302 may include a first end 304 (shown in FIG. 3). In another aspect of the current disclosure, the first end 304 may be disposed at any position on the beam 105. The fiber optic cable 302 may then extend to the first leg 122 of the drawbar member 120 and coupled along a surface 305 of the first leg 122. Thus, the fiber optic cable 302 extends along a portion of the drawbar member 120. Specifically, the fiber optic cable 302 may extend to the second leg 124 of the drawbar member 120 and coupled along a surface of the second leg 124. The fiber optic cable 302 may be then coupled with the third leg 126 and extend to a center of the third leg 126. In the illustrated aspect of the current disclosure, the fiber optic cable 302 may then extend through the circle member 160, substantially along the axis A1, from the center of the third leg 126. The fiber optic cable 302 may then travel along the arm portion 164 and coupled thereto. Alternatively, the fiber optic cable 302 may extend perpendicularly from the center of the third leg 126 and may be coupled with the outer circumference 162 of the circle member 160.
The fiber optic cable 302 may be coupled along a surface 314 of the arm portion 164. The fiber optic cable 302 may then travel to a bottom end 316 of the arm portion 164. Thus, the fiber optic cable 302 may extend along a portion of the circle member 160. From the bottom end 316, the fiber optic cable 302 may be wound around the piston rod 184 of the fourth linear actuator 180 and extend to a location 318 where the piston rod 184 is mounted on the blade 108. In another aspect of the current disclosure, the fiber optic cable 302 may further travel along the blade 108 and coupled thereto. The fiber optic cable 302 may be further configured to selectively generate signals indicative of a shape thereof.
In another aspect of the current disclosure, the fiber optic cable 302 extending between the first end 304 and a second end 306 may include multiple fiber optic cables 302. The multiple fiber optic cables 302 may be coupled each other via various methods known in the art, such as fusion splicing, and mechanical connectors etc. Further, the fiber optic cable 302 may be coupled to the various components of the actuation system 112 and the beam 105 by mechanical fasteners 310, such as clamps, clips, and the like. Further, in various aspects of the current disclosure, the fiber optic cable 302 may also be embedded at least partially in one or more components.
FIG. 3 illustrates a sectional perspective view of the fiber optic cable 302, according to an aspect of the current disclosure. The fiber optic cable 302 may extend between the first end 304 and the second end 306 defining a length ‘L’ therebetween. The fiber optic cable 302 may further include at least one core 210 that may extend between the first end 304 and the second end 306 of the fiber optic cable 302. The core 210 may be configured to be a light-carrying element. Although the fiber optic cable 302, in the illustrated aspect of the current disclosure, includes one core 210, it may be contemplated that the system 114 may include a fiber optic cable having multiple cores.
The core 210 may be further surrounded by a layer 218 of cladding 212. A material of the core 210 and the cladding 212 may be a polymer, such as polystyrene, PMMA, or the like known in the art. The material used for making the core 210 may have a high transparency and the material used for the cladding 212 may have a refractive index lower than the material of the cores 210. A difference between the refractive indices between the core 210 and the cladding 212 may provide total internal reflection of light transmitted within the core 210.
The fiber optic cable 302 may further include a plurality of strain sensors 214 distributed along a length of the core 210. Each of the plurality of strain sensors 214 may be disposed in the core 210 such that a distance between every adjacent strain sensors 214 may be kept substantially equal. Each of the strain sensors 214 may be, for example, a Fiber Bragg Gratings (FBGs) or a Rayleigh Scatter Detector. The strain sensors 214 may be further configured to estimate bending and/or twisting of the fiber optic cable 302 at each location of the strain sensor 214. The strain sensors 214 may be configured to communicate with the controller 150.
Further, a layer 218 made from a polymer may be bonded to the cladding 212. The layer 218 may act as a protective coating. More specifically, the layer 218 may act as shock absorber to protect the core 210 and the cladding 212 from damage. The layer 218 may be further surrounded by a sleeve 220 that may be made from a reinforcing polymeric material, such as aramid.
Specifically, the sleeve 220 may surround the cladding 212 along the length ‘L’ of the fiber optic cable 302. In another aspect of the current disclosure, an outer surface of the layer 218 and an inner surface of the sleeve 220 may not be bonded, adhered, or otherwise attached to each other. Hence, the cladding 212 and the core 210 may rotate freely or twist within the sleeve 220 with minimal or no friction. In another aspect of the current disclosure, the sleeve 220 may be bonded to the layer 218.
The fiber optic cable 302, shown in FIG. 2, may be exemplary and should not be treated as a limitation to the scope of the current disclosure. It may also be contemplated that the system 114 may include a fiber optic cable assembly having multiple fiber optic cables received within a jacket.
FIG. 4 shows a perspective view of an arrangement of the fiber optic cable 302 to determine a position of the implement 106, according to another aspect of the current disclosure. The first end 304 of the fiber optic cable 302 may be disposed at any position on the beam 105. The fiber optic cable 302 may then extend to the first lift arm 136 and coupled along an outer surface thereof. The fiber optic cable 302 may then extend to the first linear actuator 146 and coupled to the first lift arm 136. The fiber optic cable 302 may be wound around the cylinder 152 and the piston rod 154 and then coupled with the third leg 126. As shown in FIG. 4, the fiber optic cable 302 may extend to the center of the third leg 126. In another aspect of the current disclosure, the fiber optic cable 302 may extend to the first linear actuator 146 and coupled to the second lift arm 138. The fiber optic cable 302 may be then coupled with the third leg 126 and extend to the center of the third leg 126. In the illustrated aspect of the current disclosure, the fiber optic cable 302 may then extend through the circle member 160, substantially along the axis A1, from the center of the third leg 126. The fiber optic cable 302 may then travel along the arm portion 164 and coupled thereto. Alternatively, the fiber optic cable 302 may extend perpendicularly from the center of the third leg 126 and coupled with the outer circumference 162 of the circle member 160.
The fiber optic cable 302 may be coupled along the surface 314 of the arm portion 164. The fiber optic cable 302 may then travel to the bottom end 316 of the arm portion 164. From the bottom end 316, the fiber optic cable 302 may be wound around the piston rod 184 of the fourth linear actuator 180 and extend to the location 318 where the piston rod 184 is mounted on the blade 108. Thus, the second end 306 of the fiber optic cable 302 may be coupled adjacent to the location 318 of the piston rod 184 with the blade 108. In another aspect of the current disclosure, the second end 306 may be coupled to any location of the blade 108 to monitor the position of the implement 106. The fiber optic cable 302 may further configured to selectively generate signals indicative of a shape thereof.
The placement of the fiber optic cable 302 in the beam 105, the actuation system 112 and the implement 106, as shown in FIGS. 2 and 4, are exemplary in nature. Various alternative placements of the fiber optic cable 302 may be contemplated within the scope of the current disclosure in order to monitor the positions and orientations of the implement 106 and/or components of the actuation system 122. It may also be contemplated that one or more slacks may be provided along the length of the fiber optic cable 302 in order to facilitate movement of the fiber optic cable 302 with the movement of the implement 106 and various components of the actuation system 112.
FIG. 5 shows a block diagram illustrating the system 114 for determining the position of the implement 106, according to an aspect of the current disclosure. The system 114 may include the controller 150 configured to be in communication with the fiber optic cable 302. The controller 150 may be disposed in the operator cab 110. Alternatively, the controller 150 may be located at any location of the motor grader 100. The first end 304 of the fiber optic cable 302 may be in communication with the controller 150. In another aspect of the current disclosure, the controller 150 may also be in communication with the second end 306. The controller 150 may be further configured to determine the shape of the fiber optic cable 302 based on the signals received therefrom through the first end 304. The controller 150 may be further configured to determine a position of the implement 106 and the actuation system 112 relative to the front frame 102 based on the shape of the fiber optic cable 302.
In another aspect of the current disclosure, the controller 150 may be a microprocessor based controller. The controller 150 may include one or more microprocessors configured to process various input signals received from the fiber optic cable 302. More specifically, a receiver of the controller 150 may be configured to selectively receive optical signal corresponding to each of the strain sensors 214. Further, a transmitter of the controller 150 may be configured to transmit an optical signal to the fiber optic cable 302 in order to receive feedback from the strain sensors 214. The controller 150 may be configured to generate various outputs based on the input signals. The outputs of the controller 150 may be further communicated to a display module 151. One of the outputs may include a graphical representation of a three dimensional shape of the fiber optic cable 302, which will be described in detail with reference to FIGS. 6 and 7. The display module 151 may be disposed in the operator cab 110 to show the output to an operator. In another aspect of the current disclosure, the controller 150 may be configured to automatically regulate the actuation system 112 in order to achieve a desired position and/or orientation of the implement 106. In an example, the controller 150 may determine the position and/or orientation of the implement 106 and one or more components of the actuation system 112, such as the drawbar member 120, the circle member 160 etc., based on the shape of the fiber optic cable 302. Accordingly, the controller 150 may regulate the actuation system 112. The controller 150 may further include a memory configured to store various predetermined values, lookup tables and algorithms required to perform various functions.
FIG. 6 shows an output 600 of the system 114, according to an aspect of the current disclosure. The output 600 may correspond to an exemplary shape of the fiber optic cable 302 based on the position and/or orientation of the actuation system 112 and the implement 106 shown in FIG. 2. The controller 150 in communication with the fiber optic cable 302 may receive input signals from the strain sensors 214. Each of the strain sensors 214 may provide a signal indicative of a strain of a corresponding location of the fiber optic cable 302 upon receipt of the optical signal from the controller 150. The strain detected by each of the strain sensors 214 may correspond to bending and/or twisting of the fiber optic cable 302 at the respective location. A position of the strain sensors 214 may be determined with respect to a reference system, for example, a Cartesian coordinate system. An X-axis of the Cartesian coordinate system may correspond to the second axis A2, while an Y-axis may correspond to the first axis A1. An Z-axis may represent a longitudinal axis of the motor grader 100. In another aspect of the current disclosure, a position of the strain sensor 214 located adjacent to the front end 111 of the beam 105 may be determined as a first position point 602 of the fiber optic cable 302. In yet another aspect of the current disclosure, the strain sensor 214 located adjacent to the controller 150 may be determined as the first position point 602 of the fiber optic cable 302. The first position point 602 of the fiber optic cable 302 may correspond to the origin of the Cartesian coordinate system. Alternatively, the origin of the Cartesian coordinate system may correspond to the front end 111 of the beam 105. The controller 150 may further compute locations of the subsequent strain sensors 214 with respect to the first position point 602 based on the signals received from the respective strain sensors 214. In an exemplary aspect of the current disclosure, a position of each sensor segment of the fiber optic cable 302 may be determined based on the signal received from the corresponding strain sensors 214 and comparing the corresponding strain with the strain of adjoining sensor segments. The sensor segment may be defined as a portion of the core 210 between two adjacent strain sensors 214. Thus, the position of the sensor segments may be combined to determine the position, shape and orientation of the fiber optic cable 302.
A portion of the fiber optic cable 302 extending along the drawbar member 120 may lie substantially in a X-Z plane. The X-Z plane may be substantially parallel to a ground surface. Hence, the output 600 may indicate that a plane defined by the drawbar member 120 may be parallel to the ground surface. The output 600 may further include a first point C1 and a second point C2 along the length ‘L’ of the fiber optic cable 302. The first point C1 may be defined along the fiber optic cable 302 in order to determine an angular position of the circle member 160 relative to the drawbar member 120. A portion of the fiber optic cable 302 extending between the center of the third leg 126 and the arm portion 164 may lie substantially along the X-axis with respect to the point C1. Hence, the output 600 may indicate that the circle member 160 may be in an angular position such that the blade 108 may be substantially oriented along the second axis A2. The second point C2 may be defined in the fiber optic cable 302 to determine a position of the blade 108 relative to the retainer 172. Referring to the output 600, a portion of the fiber optic cable 302 extending between the bottom end 316 of the arm portion 164 and the fourth linear actuator 180 may lie substantially along the Y-axis. The fiber optic cable 302 lying along the Y coordinate may correspond to a retracted position of the third linear actuator 174. Further, a portion of the fiber optic cable 302 wound around the fourth linear actuator 180 may define a length IF along the X-axis that may extend between the location 318 and the second point C2. The length IF of the fiber optic cable 302 may correspond to an extended position of the piston rod 184.
In various aspects of the current disclosure, more than three coordinates may be defined along the length of the fiber optic cable 302 in order to monitor the position of the drawbar member 120 relative to the beam 105, the circle member 160 relative to the drawbar member 120 and the implement 106 relative to the retainer 172.
FIG. 7 shows an output 700 of the system 114 corresponding to the shape of the fiber optic cable 302 based on another configuration of the actuation system 112 and the implement 106. The portion of the fiber optic cable 302 extending along the drawbar member 120 may be shifted from the X-Z plane at an angle β1. Such shifting of portion of the fiber optic cable 302 may indicate movement of the first linear actuator 146 towards a retracted position thereof along the first axis A1. In such a case, a plane defined by the drawbar member 120 may be inclined with reference to ground surface. Further, the portion of the fiber optic cable 302 extending between the center of the third leg 126 and the arm portion 164 may shift from the X-axis to an angle β2 with respect to the first point C1. Such shifting of the fiber optic cable 302 may correspond to an angular position of the circle member 160 based on actuation of the electric motor. Further, the portion of the fiber optic cable 302 extending between the bottom end 316 of the arm portion 164 and the fourth linear actuator 180 may shift from the Y-axis to an angle β3 with respect to the second point C2. Such shifting of the fiber optic cable 302 may correspond to movement of the third linear actuator 174 towards an extended position thereof. Further, a reduced length ‘L2’ compared to the length ‘L1’ of the fiber optic cable 302 may correspond to movement of the fourth linear actuator 180 towards a retracted position thereof. In such case, the blade 108 may move linearly along the second axis A2 with respect to the retainer 172.
The outputs 600 and 700, as described above, are purely exemplary in nature and the fiber optic cable 302 may attain various other shapes based on relative movement between various components of the actuation system 112. Further, the first and second points C1, C2, as shown in FIGS. 6 and 7, are also illustrative in nature. It may be contemplated to monitor the position of any point along the fiber optic cable 302 in order to determine the positions and orientations of the implement 106 and/or various components of the actuation system 112.

INDUSTRIAL APPLICABILITY

The current disclosure relates to the system 114 and a method 800 of monitoring the position of the implement 106 of the motor grader 100 relative to the front frame 102. The controller 150 of the system 114 may receive signals generated by the fiber optic cable 302 and determine the position of the implement 106 based on the shape of the fiber optic cable 302.
FIG. 8 shows a flowchart of the method 800 of determining the position of the actuation system 112 and the implement 106, according to an aspect of the current disclosure. The method 800 may be described in detail with respect to various steps.
At step 802, the method 800 may include providing the fiber optic cable 302 along at least the portion of the front frame 102, the portion of the actuation system 112 and the portion of the implement 106. In another aspect of the current disclosure, the fiber optic cable 302 may be coupled with the beam 105, the drawbar member 120, the circle member 160 and the fourth linear actuator 180 in order to monitor various positions of the implement 106. Further, various positions of the actuation system 112 and the circle member 160 may also be monitored. In another aspect of the current disclosure, the fiber optic cable 302 may be coupled with the beam 105, the first linear actuator 146, the circle member 160 and the fourth linear actuator 180 in order to monitor various positions of the implement 106.
At step 804, the method 800 may include receiving signals from the fiber optic cable 302. The controller 150 in communication with the first end 304 of the fiber optic cable 302 may receive signals therefrom. The receiver of the controller 150 may selectively receive optical signal corresponding to each of the strain sensors 214. Further, the transmitter of the controller 150 may be configured to transmit an optical signal to the fiber optic cable 302 in order to receive strain from respective locations of the strain sensors 214. The strain sensors 214 may transmit signals indicative of bending and/or twisting of the fiber optic cable 302 at corresponding locations of the strain sensor 214.
At step 806, the method 800 may include determining the shape of the fiber optic cable 302 based on the received signals. The position of the strain sensor 214 located adjacent to the front end 111 of the beam 105 may be determined as the first position point 602 of the fiber optic cable 302. The controller 150 may further determine locations of the subsequent strain sensors 214 with respect to the first position point 602. In another aspect of the current disclosure, position of each of the sensor segments may be determined based on the strain data received from the corresponding strain sensors 214 and comparing the data with adjoining segments. The data for each of the segments may be combined to determine the position, shape and orientation of the fiber optic cable 302.
At step 808, the method 800 may include determining the position of the implement 106 relative to the front frame 102 based on the shape of the fiber optic cable 302. The origin of the Cartesian coordinate system corresponds to the first position point 602. The first position point 602 may correspond to the position of the strain sensor 214 located in the fiber optic cable 302 adjacent to the front end 111 of the beam 105. The shape and orientation of the portion of the fiber optic cable 302 extending along the drawbar member 120 may correspond to the position of the drawbar member 120 relative to the front frame 102. Further, the shape and orientation of the portion of the fiber optic cable 302 extending between the center of the third leg 126 and the arm portion 164 with respect to the first point C1 may correspond to the angular position of the circle member 160 relative to the drawbar member 120. Further, the shape and orientation of the portion of the fiber optic cable 302 extending between the bottom end of the arm portion 164 and the fourth linear actuator 180 with respect to the second point C2 may correspond to the angular position of the blade 108 relative to the retainer 172. Further, a variation in a length of the fiber optic cable 302 between the second point C2 and the location 318 may correspond to linear movement of the blade 108 with respect to the retainer 172.
Thus, the system 114 and the method 800 of the current disclosure monitor various positions of the implement 106 relative to the front frame 102. Specifically, linear movement of the blade 108 with respect to the retainer 172 and angular movement of the blade 108 with respect to the bottom end 316 of the arm portion 164 may be monitored through the controller 150. Further, inclination of the blade 108 about the first axis A1 and the longitudinal axis may also be monitored. Further, the outputs 600, 700 generated by the controller 150 may facilitate the operator to locate exact position of the implement 106 relative to the front frame 102, and hence the position of the implement 106 relative to the surface of the ground.
Further, the fiber optic cable 302 attached to the actuation system 112 and the implement 106 may travel through various mechanical joints (E.g., the ball and socket joint between the beam 105 and the drawbar member 120) so that only a minimum portion of the fiber optic cable 302 may be moved relative to another moving portion of the fiber optic cable 302, for example, the portions of the fiber optic cable 302 attached to the drawbar member 120 and the circle member 160. Further, any malfunction in the movement of the drawbar member 120, the circle member 160, the first linear actuator 146, the second linear actuator 156, the third linear actuator 174 and the fourth linear actuator 180 may be identified.
While the current disclosure have been particularly shown and described with reference to the aspects above, it will be understood by those skilled in the art that various additional aspects may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such aspects should be understood to fall within the scope of the current disclosure as determined based upon the claims and any equivalents thereof.

Claims

What is claimed is:

1. A system for monitoring a position of an implement of a motor grader relative to a frame of the motor grader, the motor grader having an actuation system configured to selectively move the implement relative to the frame, the system comprising:

a fiber optic cable extending along at least a portion of the frame, a portion of the actuation system and a portion of the implement, wherein the fiber optic cable is configured to move with the portion of the actuation system and the portion of the implement, and wherein the fiber optic cable is further configured to selectively generate signals indicative of a shape thereof; and

a controller in communication with the fiber optic cable, wherein the controller is configured to determine the shape of the fiber optic cable based on the signals received therefrom, and wherein the controller is further configured to determine a position of the implement relative to the frame based on the shape of the fiber optic cable.

2. The system of claim 1, the fiber optic cable comprising at least one core and a plurality of strain sensors distributed along a length of the at least one core.

3. The system of claim 2, wherein each of the plurality of strain sensors is one of a Fiber Bragg Grating (FBG) sensor and Rayleigh Scatter Detector.

4. The system of claim 1, wherein the controller is further configured to regulate the actuation system to move the implement based on at least a user input and the position of the implement.

5. The system of claim 1, wherein the controller is further configured to transmit an optical signal to the fiber optic cable.

6. The system of claim 1 further comprising mechanical fasteners configured to couple the fiber optic cable to at least the frame, the actuation system and the implement.

7. A motor grader comprising:

a frame;

an implement movable relative to the frame;

an actuation system coupled to the frame and the implement, the actuation system configured to selectively move the implement relative to the frame;

8. The motor grader of claim 7, the fiber optic cable comprising at least one core and a plurality of strain sensors distributed along a length of the at least one core.

9. The motor grader of claim 8, wherein each of the plurality of strain sensors is one of a Fiber Bragg Grating (FBG) sensor and Rayleigh Scatter Detector.

10. The motor grader of claim 7, wherein the controller is further configured to regulate the actuation system to move the implement based on at least a user input and the position of the implement.

11. The motor grader of claim 7, wherein the controller is further configured to transmit an optical signal to the fiber optic cable.

12. The motor grader of claim 7, further comprising mechanical fasteners configured to couple the fiber optic cable to at least the frame, the actuation system and the implement.

13. The motor grader of claim 7, wherein the actuation system comprising:

a drawbar member movably coupled to the frame; and

a circle member rotatably coupled to the drawbar member, the circle member comprising an arm portion pivotally coupled to the implement.

14. The motor grader of claim 13, wherein the fiber optic cable extends along a portion of the drawbar member and a portion of the circle member.

15. The motor grader of claim 13, wherein the actuation system further comprising:

a support member coupled to the frame;

a first linear actuator coupled to the support member and the drawbar member, the first linear actuator configured to move the drawbar member along a first axis;

a second linear actuator coupled to the support member and the drawbar member, the second linear actuator configured to move the drawbar member along a second axis perpendicular to the first axis; and

a rotary actuator coupled to the circle member, the rotary actuator configured to rotate the circle member about the first axis.

16. The motor grader of claim 15, wherein the fiber optic cable extends along a portion of the support member, a portion of the first linear actuator, a portion of the drawbar member and a portion of the circle member.

17. The motor grader of claim 15, wherein the actuation system further comprising:

a third linear actuator coupled to the circle member and the implement, the third linear actuator configured to rotate the implement relative to the arm portion of the circle member about the second axis; and

a fourth linear actuator coupled to the circle member and the implement, the fourth linear actuator configured to slide the implement relative to arm portion the along the second axis.

18. The motor grader of claim 17, wherein the fiber optic cable is coupled to the fourth linear actuator.

19. A method of monitoring a position of an implement of a motor grader relative to a frame of the motor grader, the motor grader having an actuation system configured to selectively move the implement relative to the frame, the method comprising:

providing a fiber optic cable along at least a portion of the frame, a portion of the actuation system and a portion of the implement, wherein the fiber optic cable is configured to move with the portion of the actuation system and the portion of the implement;

receiving signals from the fiber optic cable, wherein the signals are indicative of a shape of the fiber optic cable;

determining the shape of the fiber optic cable based on the received signals; and

determining a position of the implement relative to the frame based on the shape of the fiber optic cable.

20. The method of claim 19, further comprising transmitting an optical signal to the fiber optic cable.