Patent Publication Number: US-2023151583-A1

Title: Collision avoidance system and method for avoiding collision of work machine with obstacles

Description:
TECHNICAL FIELD 
     The present disclosure relates to a collision avoidance system and a method for avoiding collision of a work machine with one or more obstacles. 
     BACKGROUND 
     Work machines, such as, excavators, motor graders, loaders, and the like may be used at various construction worksites to perform operations, such as, material removal, transportation, and the like. Such work machines typically operate in highly interactive environments with ground crew moving around the work machine, varying road surfaces being cut and repaired, and barriers and obstacles that need to be navigated by the work machine. It may be challenging for an operator to be aware of such dynamic environments and accordingly navigate the work machine. More particularly, a visibility of the operator may be obstructed by portions of the work machine itself or other obstacles present near the work machine. 
     In some examples, if the operator is unaware of one or more obstacles that may be present in a path of the work machine, there may be a possibility of a collision between the work machine and the obstacle, which may not be desired. Thus, it may be desirable to have a technique that prevents collision of manual, semi-autonomous, or autonomous work machines with objects present at the worksite to ensure efficient operations at the worksite. 
     U.S. Pat. No. 9,415,976 describes a crane collision avoidance system. One example includes a load locator to determine a location of a load of a crane and provide the location information to a mapping module. In addition, a map receiver module procures a map of a site and provides the map to the mapping module. A tag scanner scans the site for one or more tags defining an obstacle and provides the obstacle information to a mapping module. The mapping module combines the location information, the map and the obstacle information into a user accessible information package that is displayed on a graphical user interface. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a collision avoidance system for a work machine is provided. The collision avoidance system includes at least one sensor configured to generate a signal indicative of a presence of at least one obstacle in a surrounding area of the work machine. The collision avoidance system also includes a controller communicably coupled with the sensor. The controller is configured to receive the signal indicative of the presence of the obstacle in the surrounding area of the work machine from the sensor. The controller is also configured to determine a position of the obstacle relative to the work machine based on the signal received from the sensor. The controller is further configured to generate a control signal to at least one of prevent a movement of the work machine, halt the movement of the work machine, and reduce a velocity of the work machine based on the determination of the position of the obstacle. 
     In another aspect of the present disclosure, a method for avoiding collision of a work machine with at least one obstacle is provided. The method includes generating, by at least one sensor, a signal indicative of a presence of the at least one obstacle in a surrounding area of the work machine. The method also includes receiving, by the controller, the signal indicative of the presence of the obstacle in the surrounding area of the work machine from the sensor. The method further includes determining, by the controller, a position of the obstacle relative to the work machine based on the signal received from the sensor. The method includes generating, by the controller, a control signal to at least one of prevent a movement of the work machine, halt the movement of the work machine, and reduce a velocity of the work machine based on the determination of the position of the obstacle. 
     In yet another aspect of the present disclosure, a work machine is provided. The work machine includes a frame. The work machine also includes a plurality of ground engaging members supported by the frame. The work machine further includes a collision avoidance system. The collision avoidance system includes at least one sensor configured to generate a signal indicative of a presence of at least one obstacle in a surrounding area of the work machine. The collision avoidance system also includes a controller communicably coupled with the sensor. The controller is configured to receive the signal indicative of the presence of the obstacle in the surrounding area of the work machine from the sensor. The controller is also configured to determine a position of the obstacle relative to the work machine based on the signal received from the sensor. The controller is further configured to generate a control signal to at least one of prevent a movement of the work machine, halt the movement of the work machine, and reduce a velocity of the work machine based on the determination of the position of the obstacle. 
     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    illustrates a side view of a work machine and an obstacle present around the work machine, according to examples of the present disclosure; 
         FIG.  2    illustrates a block diagram of a collision avoidance system associated with the work machine of  FIG.  1   , according to examples of the present disclosure; and 
         FIG.  3    illustrates a flowchart for a method for avoiding collision of the work machine with one or more obstacles, according to examples of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. 
       FIG.  1    illustrates an exemplary work machine  100  operating at a worksite  102 . The work machine  100  is embodied as a hydraulic excavator herein. Accordingly, the work machine  100  may perform one or more excavation operations at the worksite  102 . Although shown as the hydraulic excavator, it may be understood that the work machine  100  may alternatively include other work machines, such as, motor graders, loaders, mining shovels, dozers, tractors, or compactors, without any limitations. Further, the work machine  100  may include a manual machine, an autonomous machine, or a semi-autonomous machine. 
     The work machine  100  may move in a forward direction “F” or a reverse direction “R”. The work machine  100  defines a front end  104  and a rear end  106 . Further, the work machine  100  defines a first side  108  embodied as a left side of the work machine  100  in relation to the movement of the work machine  100  in the forward direction “F”. Moreover, the work machine  100  defines a second side (not shown) opposite to the first side  108  and embodied as a right side of the work machine  100  in relation to the movement of the work machine  100  in the forward direction “F”. 
     The work machine  100  includes a lower structure  112  and an upper structure  114  movably coupled with the lower structure  112 . The work machine  100  includes a frame  116 . Specifically, the upper structure  114  defines the frame  116 . The upper structure  114  may support various components of the work machine  100  thereon. The upper structure  114  defines an enclosure  118 . The enclosure  118  allows mounting of a power source (not shown). The power source may provide operating power to the work machine  100  for mobility and operational requirements. The power source may include, but is not limited to, a diesel engine, a gasoline engine, a gaseous fuel powered engine, a dual fuel powered engine, an electric motor, a fuel cell, a battery, and/or a combination thereof, based on application requirements. Additionally, the work machine  100  may include components (not shown) and/or systems (not shown), such as a braking system, a fuel delivery system, an air delivery system, an exhaust system, a drivetrain, a hydraulic system, a transmission system, and so on, based on application requirements. 
     The work machine  100  may also include a work implement  120  disposed proximate to the front end  104 . The work implement  120  may be operably connected to the upper structure  114  by a linkage assembly  122 . The work implement  120  may be used for various material handling operations, material removal operations, and/or material transportation operations. For example, during an excavation operation, the work implement  120  may contact ground surfaces for removing material therefrom. 
     Further, the work machine  100  includes a number of ground engaging members  124  supported by the frame  116 . The ground engaging members  124  may provide support and mobility to the work machine  100  on ground surfaces. As such, the ground engaging members  124  may enable travel/tramming of the work machine  100  on ground surfaces. In the illustrated embodiment of  FIG.  1   , the work machine  100  includes two ground engaging members  124  (only one ground engaging member  124  is shown in the accompanying figure) disposed at each of the first side  108  and the second side of the work machine  100 . In the illustrated example of  FIG.  1   , the ground engaging members  124  are embodied as tracks. In other examples, the ground engaging members  124  may embody wheels or drums. 
     The work machine  100  includes a turn table  126 . The turn table  126  may be mounted on the lower structure  112 , upon which the upper structure  114 , including an operator cabin  128 , may be pivotally mounted. The operator cabin  128  is supported by the frame  116 . The operator cabin  128  may move relative to the lower structure  112 . Further, the operator cabin  128  may include one or more input devices  130  (shown in  FIG.  2   ). The input devices  130  may include a lever, a pedal, a button, a joystick, and the like. In some examples, the input devices  130  may include a first sensor  132  associated therewith. Further, the sensor  132  may include a single sensor or a combination of sensors. The first sensor  132  may embody a position sensor that may generate a signal “I 1 ” indicative of a position of a corresponding input device  130 . For example, if the input device  130  is being used to effectuate a movement of the linkage assembly  122  or the work implement  120  towards the first side  108  or the second side of the work machine  100 , the signal “I 1 ” from the first sensor  132  may indicate if the linkage assembly  122  or the work implement  120  is moving towards or is disposed at the first side  108  or the second side of the work machine  100 . In another example, if the input device  130  is being used to effectuate a movement of the ground engaging members  124 , the signal “I 1 ” from the first sensor  132  may indicate if the ground engaging members  124  are moving in the forward direction “F” or the reverse direction “R”. 
     Moreover, the operator cabin  128  may include one or more output devices  134  (shown in  FIG.  2   ). In an example, the output device  134  may include a display screen. In some examples, the output device  134  may embody a touch screen device that may include means to provide outputs to the machine operator and may also include means to receive inputs, that may be physical inputs or virtual inputs, from the machine operator. In some examples, the input and output devices  130 ,  134  may be present at a base station (not shown) which may be located remotely with respect to the work machine  100 . For example, the input and output devices  130 ,  134  may be disposed at the base station that may be located offsite. 
     Further, the work machine  100  may include a second sensor  136  (shown in  FIG.  2   ) that generates signals “I 2 ” indicative of a direction of movement of one or more movable components of the work machine  100 . Further, the sensor  136  may include a single sensor or a combination of sensors. The second sensor  136  may include an inertial measurement unit (IMU). The IMU may be mounted at any location on the linkage assembly  122 , the work implement  120 , the upper structure  114 , the lower structure  112 , and the like. In an example, the second sensor  136  may include a gyroscopic device. In some examples, the second sensor  136  may include a swing angle sensor. 
     Further, the second sensor  136  may be mounted on the linkage assembly  122  or the work implement  120 , such that the second sensor  136  generates the signals “I 2 ” indicative of the swing movement of the linkage assembly  122  or the work implement  120 . Furthermore, the second sensor  136  may be mounted on the ground engaging members  124 , such that the second sensor  136  generates the signals “I 2 ” indicative of the direction of the movement of the ground engaging members  124 . In some examples, the second sensor  136  may be mounted on the turn table  126 , such that the second sensor  136  generates the signals “I 2 ” indicative of the movement of the upper structure  114  relative to the lower structure  112 . It should be noted that a type of the second sensor  136  mentioned herein does not limit the scope of the present disclosure and the work machine  100  may include any other type of sensor that may provide the desired features. 
     As shown in  FIG.  2   , the present disclosure relates to a collision avoidance system  200  for a work machine  100 . The collision avoidance system  200  includes one or more sensors  202  to generate a signal “I 3 ” indicative of a presence of one or more obstacles  142  (shown in  FIG.  1   ) in a surrounding area  140  (shown in  FIG.  1   ) of the work machine  100 . The obstacle  142  may include an infrastructure, another work machine, a pile of material, a personnel, and the like. Although a single obstacle  142  embodied as a pile of material is illustrated in  FIG.  1   , it should be noted that the worksite  102  (see  FIG.  1   ) may include multiple obstacles of different shapes and sizes present thereon. It should be further noted that, although the obstacle  142  are positioned on the ground surface herein, it may be contemplated that the worksite  102  may include overhead or hanging obstacles that may be either in a suspended form, such as, cranes, or may be movable obstacles, such as, drones, without any limitations. 
     Further, as shown in  FIG.  2   , the sensor  202  may include a single sensor or a combination of sensors. The sensor  202  may be mounted on the work machine  100 . For example, the sensor  202  may be mounted on the upper structure  114  (see  FIG.  1   ) of the work machine  100 . In an example, the sensor  202  may be mounted on top of the operator cabin  128  (see  FIG.  1   ) of the work machine  100 . In some examples, the sensor  202  may include one or more of a perception sensor and a proximity sensor. In an example, the sensor  202  may include an image capturing device. More particularly, the sensor  202  may embody a camera mounted on the work machine  100 . The image capturing device may include any other type of device generally known in the art, such as, a camcorder, a closed-circuit television (CCTV), and the like. In an example, the image capturing device may include a digital video camera, such as, an ethernet camera to provide an electronic motion picture acquisition. In some examples, the image capturing device may embody monocular lens cameras or a combination of monocular lens cameras and stereo/triple lens cameras, without any limitations. It should be noted that the present disclosure is not limited by a type of the image capturing device. Further, the work machine  100  may include a single image capturing device or multiple image capturing devices mounted at different locations on the work machine  100 . The image capturing device may be used to sense the surrounding area  140  of the work machine  100 . For example, the image capturing device may capture images or videos of the surrounding area  140  of the work machine  100 . 
     In other examples, the sensor  202  may embody a Light Detection and Ranging (LiDAR) sensor or a Radio Detection and Ranging (RADAR) sensor, without any limitations. In some examples, the sensor  202  may include a combination of the image capturing device, the LiDAR sensor, and the RADAR sensor. It should be noted that the present disclosure is not limited by a type of the sensor  202 , and the sensor  202  may include any type of sensor that provides the desired functionalities. In an example, the signals “I 3 ” generated by the sensor  202  may be used to determine a distance “D 1 ” (shown in  FIG.  1   ) between the obstacle  142  and the work machine  100  or a bearing angle of the obstacle  142  from the work machine  100 . In some examples, the distance “D 1 ” may be defined between the obstacle  142  and the frontmost portion of the work machine  100 . 
     Further, the collision avoidance system  200  includes a controller  204  communicably coupled with the sensor  202 . The controller  204  may be present onboard the work machine  100 . In an example, the controller  204  may embody a central control unit associated with the work machine  100  that may be capable of controlling numerous machine functions. Alternatively, the controller  204  may embody an off-board controller. The controller  204  may embody a single microprocessor or multiple microprocessors for receiving various input signals from various components of the work machine  100 . Numerous commercially available microprocessors may be configured to perform the functions of the controller  204 . The controller  204  may include a central processing unit, a graphics processing unit, and the like. The controller  204  may also include a processing logic, such as, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and the like. 
     The controller  204  includes a memory  206 . The memory  206  may include a flash memory, a random-access memory (RAM), an electrically erasable programmable read-only memory (EEPROM), and the like. The memory  206  may be used to store data, such as, algorithms, instructions, arithmetic operations, and the like. The controller  204  may execute various types of digitally-stored instructions, such as, a software or an algorithm, retrieved from the memory  206 , or a firmware program which may enable the controller  204  to perform a wide variety of operations. 
     The controller  204  receives the signal “I 3 ” indicative of the presence of the obstacle  142  in the surrounding area  140  of the work machine  100  from the sensor  202 . Further, the controller  204  determines a position of the obstacle  142  relative to the work machine  100  based on the signal “I 3 ” received from the sensor  202 . In some examples, the controller  204  may determine the position of the obstacle  142  based on the analysis of the signal “I 3 ” received from the sensor  202 . In an example, when the sensor  202  includes the image capturing device, the controller  204  may determine the position of the obstacle  142  based on a mounting position of the image capturing device i.e., a height and an angle at which the image capturing device is mounted. Additionally, the controller  204  may analyze the obstacle  142  in a field of the view of the image capturing device. Based on the analysis, the controller  204  may determine the distance “D 1 ” between the obstacle  142  and the work machine  100  or the bearing angle of the obstacle  142  from the work machine  100 . It should be noted that the parameters i.e., the distance “D 1 ” and the bearing angle mentioned herein are exemplary in nature and the controller  204  may determine the position of the obstacle  142  based on other parameters not mentioned herein, without any limitations. 
     Further, the controller  204  generates a control signal “O 1 ” to prevent a movement of the work machine  100 , halt the movement of the work machine  100 , or reduce a velocity of the work machine  100  based on the determination of the position of the obstacle  142 . The controller  204  may generate the control signal “O 1 ” based on one or more of the distance “D 1 ” between the obstacle  142  and the work machine  100  and the bearing angle of the obstacle  142  from the work machine  100 . 
     It should be further noted that the controller  204  may compare the position of the work machine  100  with the direction of movement of one or more movable components of the work machine  100  for generating the control signal “O 1 ”. The movable components may include the linkage assembly  122  (see  FIG.  1   ), the work implement  120  (see  FIG.  1   ), the ground engaging members  124  (see  FIG.  1   ), the upper structure  114 , etc. For this purpose, the controller  204  may be in communication with the first sensor  132  and the second sensor  136 . In some examples, the controller  204  may determine the direction of movement of the work machine  100  itself for generating the control signal “O 1 ”. In some examples, data received from the first and/or second sensors  132 ,  136  may assist the controller  204  in determining the direction of movement of the one or more movable components of the work machine  100 . For example, when the obstacle  142  may be present at the first side  108  (see  FIG.  1   ) of the work machine  100 , and the linkage assembly  122  is swinging towards the first side  108  of the work machine  100 , the first and/or second sensor  132 ,  136  may generate the signals “I 1 ”, “I 2 ” indicating the movement of the linkage assembly  122  towards the first side  108 . Based on the signals “I 1 ”, “I 2 ” received from the first and/or second sensors  132 ,  136  indicating the movement of the linkage assembly  122  towards the first side  108  and the signals “I 3 ” received from the sensor  202  indicating the presence of the obstacle  142  on the first side  108 , the controller  204  may generate the control signal “O 1 ” to prevent the movement, halt the movement, or reduce the velocity of the work machine  100 . 
     In some examples, the controller  204  may compare the distance “D 1 ” between the obstacle  142  and the work machine  100  with a predetermined distance value “V 1 ” between the obstacle  142  and the work machine  100  for generating the control signal “O 1 ”. The predetermined distance value “V 1 ” may be stored within the memory  206  associated with the controller  204  and may be retrieved from the memory  206  as and when required. Further, the controller  204  may generate the control signal “O 1 ” if the distance “D 1 ” between the obstacle  142  and the work machine  100  is less than the predetermined distance value “V 1 ” between the obstacle  142  and the work machine  100 . 
     Further, the controller  204  may generate the control signal “O 1 ” to halt the movement of the work machine  100  or reduce the velocity of the work machine  100  based on the position of the obstacle  142 . For example, if the distance “D 1 ” between the work machine  100  and the obstacle  142  is greater than a predefined value “V 2 ”, the controller  204  may generate the control signal “O 1 ” to reduce the velocity of the work machine  100 . It should be noted that the velocity of the work machine  100  may be determined based on the distance “D 1 ” between the obstacle  142  and the work machine  100  and/or the bearing angle of the obstacle  142  from the work machine  100 . 
     However, if the distance “D 1 ” between the work machine  100  and the obstacle  142  is lesser than the predefined value “V 2 ”, the controller  204  may generate the control signal “O 1 ” to halt the movement of the work machine  100 . The predefined value “V 2 ” between the work machine  100  and the obstacle  142  may be stored within the memory  206  associated with the controller  204  and may be retrieved from the memory  206  as and when required. It should be noted that the predetermined distance value “V 1 ” and the predefined value “V 2 ” may be decided on a variety of factors, such as, a size of the work machine  100 , a terrain at the worksite  102 , a size of the worksite  102 , and the like. In some examples, the machine operator may be able to adjust the predetermined distance value “V 1 ” and the predefined value “V 2 ”, as per application requirements. 
     Further, in some examples, the controller  204  may determine the position of the obstacle  142  before initiating the movement of the work machine  100 . In such an example, the controller  204  may generate the control signal “O 1 ” to prevent the movement of the work machine  100  based on the determination of the position of the obstacle  142 . More particularly, in a situation wherein the work machine  100  is about to move in the forward direction “F” and the controller  204  determines a presence of the obstacle  142  proximate to the front end  104  of the work machine  100 , the controller  204  may generate the control signal “O 1 ” to prevent the movement of the work machine  100  in the forward direction “F”. It should be noted that the data corresponding to the movement of the work machine  100  in the forward direction “F” may be received from the first or second sensor  132 ,  136 . 
     Moreover, in some examples, the controller  204  may determine the position of the obstacle  142  during the movement of the work machine  100 . In such an example, the controller  204  may generate the control signal “O 1 ” to halt the movement of the work machine  100  or reduce the velocity of the work machine  100  based on the determination of the position of the obstacle  142 . More particularly, in a situation wherein the work machine  100  is moving in the reverse direction “R” and the controller  204  determines a presence of the obstacle  142  proximate to the rear end  106  (see  FIG.  1   ) of the work machine  100 , the controller  204  may generate the control signal “O 1 ” to halt the movement of the work machine  100  or reduce the velocity of the work machine  100  while the work machine  100  is moving in the reverse direction “R”. It should be noted that the data corresponding to the movement of the work machine  100  or the movable components of the work machine  100  may be received from the first and/or second sensors  132 ,  136 . 
     Further, the control signal “O 1 ” generated by the controller  204  may be transmitted to the braking system of the work machine  100 , the transmission system of the work machine  100 , the drivetrain of the work machine  100 , or any other component of the work machine  100  that may allow control of the movement of the work machine  100 , without any limitations. In some examples, the velocity of the work machine  100  may be controlled based on a control of the ground engaging members  124 . In such examples, the control signal “O 1 ” may be transmitted to components, such as, hydraulic valves or hydraulic motors, that may operate the ground engaging members  122 , so that the work machine  100  may move at a desired velocity. In some examples, the controller  214  may generate the first control signal “O 1 ” to control a velocity of one or more movable components of the work machine  100 . 
     In some examples, the collision avoidance system  200  may allow an operator to override the control signal “O 1 ” generated by the controller  204 . In such examples, the controller  204  may generate a prompt screen on the output device  134 . The prompt screen may include an option to continue with a control of the work machine  100  based on the control signal “O 1 ” generated by the controller  204  or override the control signal “O 1 ” generated by the controller  204 . 
     If the machine operator chooses to continue with the control of the work machine  100 , the controller  204  may control the movement of the work machine  100  based on the generated control signal “O 1 ”. However, if the machine operator chooses to override the control signal “O 1 ”, the controller  204  may not intervene with the movements of the work machine  100 . It should be noted that the machine operator may choose to override the control signal “O 1 ” in situations wherein the obstacle  142  is small in size, the machine operator may be able to easily navigate the work machine  100  around the obstacle  142 , and the like. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure relates to the collision avoidance system  200  and a method  300  for avoiding collision of the work machine  100  with one or more obstacles  142 . The collision avoidance system  200  may collect real time and accurate information regarding the presence of one or more obstacles  142  around the work machine  100  and accordingly control the movements of the work machine  100  to eliminate any possibility of collision between the obstacle  142  and the work machine  100 . The collision avoidance system  200  may provide 360 Degrees viewability around the work machine  100 . More particularly, the collision avoidance system  200  may include the one or more sensors  202  that may provide real time data of one or more obstacles  142  that may be present around the work machine  100 . Further, in some examples, the collision avoidance system  200  may allow the machine operator to override the control signal “O 1 ” generated by the controller  202 , as per requirements. 
     The collision avoidance system  200  may increase operational safety of the work machine  100  by providing a means to monitor the surrounding area  140  of the work machine  100  and may also take appropriate actions based on detection of the one or more obstacles  142 . The collision avoidance system  200  may be simple in operation and cost effective. Further, the collision avoidance system  200  may be easily retrofitted on existing work machines, without modifying hardware associated with existing work machines. The collision avoidance system  200  may be used with autonomous, semi-autonomous, or manual machines, without any limitations. Further, the collision avoidance system  200  may embody an inclusive and onboard machine system as the collision avoidance system  200  may not require additional inputs from other work machines or other sensors present at the worksite  102 . 
       FIG.  3    illustrates a flowchart for the method  300  for avoiding collision of the work machine  100  with one or more obstacles  142 . At step  302 , the one or more sensors  202  generate the signal “I 3 ” indicative of the presence of the one or more obstacles  142  in the surrounding area  140  of the work machine  100 . The sensor  202  may be mounted on the work machine  100 . Further, the sensor  202  may include one or more of the perception sensor and the proximity sensor. At step  304 , the controller  204  receives the signal “I 3 ” indicative of the presence of the obstacle  142  in the surrounding area  140  of the work machine  100  from the sensor  202 . At step  306 , the controller  204  determines the position of the obstacle  142  relative to the work machine  100  based on the signal “I 3 ” received from the sensor  202   
     At step  308 , the controller  204  generates the control signal “O 1 ” to prevent the movement of the work machine  100 , halt the movement of the work machine  100 , or reduce the velocity of the work machine  100  based on the determination of the position of the obstacle  142 . Further, the controller  204  may generate the control signal “O 1 ” based on one or more of the distance “D 1 ” between the obstacle  142  and the work machine  100  and the bearing angle of the obstacle  142  from the work machine  100 . Furthermore, the controller  204  may compare the position of the work machine  100  with the direction of movement of one or more movable components of the work machine  100  for generating the control signal “O 1 ”. Moreover, the controller  204  may generate the control signal “O 1 ” if the distance “D 1 ” between the obstacle  142  and the work machine  100  is less than the predetermined distance value “V 1 ” between the obstacle  142  and the work machine  100 . 
     In an example, the controller  204  may determine the position of the obstacle  142  before initiating the movement of the work machine  100 . Further, the controller  204  may generate the control signal “O 1 ” to prevent the movement of the work machine  100  based on the determination of the position of the obstacle  142 . In another example, the controller  204  may determine the position of the obstacle  142  during the movement of the work machine  100 . Further, the controller  204  may generate the control signal “O 1 ” to halt the movement of the work machine  100  or reduce the velocity of the work machine  100  based on the determination of the position of the obstacle  142 . 
     It may be desirable to perform one or more of the steps shown in  FIG.  3    in an order different from that depicted. Furthermore, various steps could be performed together. 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments 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 embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.