Patent Publication Number: US-11032967-B2

Title: Autonomous or remote-controlled vehicle platform for planting

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/708,909, filed Sep. 19, 2017, which claims priority and the benefit of the filing date based on U.S. provisional application No. 62/511,549, filed May 26, 2017 under 35 U.S.C. § 119 (e), wherein the entirety of each of the aforementioned applications is hereby incorporated by reference herein. 
    
    
     FIELD OF INVENTION 
     This disclosure relates to an autonomous or remote controlled vehicle platform for planting. 
     BACKGROUND 
     In some prior art, agricultural vehicles have a gantry configuration for suspending or supporting one or more implements for performing agricultural tasks. Certain prior art gantry configurations may lack lateral adjustment of the planting row units with respect to the vehicle, which can result in planted rows of seeds or swaths that are not parallel to each other or that do not track a target path plan, such as linear row segments, contour row segments, curved row segments or spiral row segments. Other prior art gantry configurations may be associated with wheels that unduly compact the soil, which can detract from favorable growing conditions of plants or crops. Thus, there is a need for a gantry configuration that provides lateral adjustment of the planting row units, while minimizing soil compaction. 
     SUMMARY 
     In accordance with one embodiment, a vehicle platform comprises a central body that can support one or more implement configurations, such as sprayer booms, or planting row units. A plurality of adjustable legs extends downward from the central body. Each adjustable leg has a corresponding leg actuator to adjust a respective vertical height of each adjustable leg. Each adjustable leg supports the central body. Planting row units are supported by or suspended from the central body (e.g., via a pivotable arm assembly). Each planting row unit comprises an opener (e.g., opener assembly) for opening the soil (e.g., a furrow or groove in the soil), a seed tube with a seed outlet or other seed delivery device, for planting seed in the opened soil, and a closer for closing or covering seed with soil. The planting row unit comprises a bin for holding seed, the bin coupled to a seed metering unit for controlling the rate of seed provided to a seed outlet associated with or near the opener. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective top, rear, and side view of one embodiment of an autonomous or remote-controlled vehicle, such as a sprayer. 
         FIG. 2  is a perspective top, front, and side view of the autonomous or remote-controlled vehicle of  FIG. 1 . 
         FIG. 3A  is a rear elevation view of the vehicle of  FIG. 1 . 
         FIG. 3B  is a plan view of the vehicle of  FIG. 1 . 
         FIG. 4A  is side of view of a track assembly as viewed along reference line  4 - 4  of  FIG. 1 . 
         FIG. 4B  is side of view of a track assembly of  FIG. 4A  wherein the ground contact area is contracted. 
         FIG. 4C  is a side view of a track assembly of  FIG. 4A  wherein the ground contact area is expanded. 
         FIG. 5A  is a perspective top, front and side view of another embodiment of the vehicle configured with planting row units. 
         FIG. 5B  is perspective view of yet another embodiment of the vehicle configured with planting row units that are laterally adjustable. 
         FIG. 5C  is a side view of an enlarged portion of  FIG. 5B  within rectangular area labeled  5 , as indicated by the dashed lines. 
         FIG. 6  is a front perspective view of an alternate embodiment of a vehicle which illustrates legs with rectangular cross-sections. 
         FIG. 7  is a perspective view of another alternate embodiment of the vehicle which illustrates a framework of a sprayer boom implement that can support a set of nozzles or Y-drop set of nozzles. 
         FIG. 8A  and  FIG. 8B  (collectively  FIG. 8 ) are a block diagram of a control system for the autonomous or remote-controlled vehicle. 
         FIG. 9  is flow chart of method for controlling a track assembly of the autonomous or remote-controlled vehicle. 
     
    
    
     Like reference numbers in any set of drawings indicates like elements or features. 
     DETAILED DESCRIPTION 
     In accordance with  FIG. 2  through  FIG. 3B , inclusive, one embodiment of a vehicle platform  11  comprises a central body  10 . A plurality of adjustable legs  12  extends downward from the central body  10 . Each adjustable leg  12  has a corresponding leg actuator  37 , such as a linear actuator, an electric motor with a screw, or a hydraulic cylinder with an electrohydraulic interface, to adjust a respective vertical height  33  of each adjustable leg  12 . For example, in a self-leveling control mode, the vehicle height control module  822  or the data processor  800  can control the leg actuators  37  to maintain a level attitude of the vehicle based on measurements of any of the following: motion sensors  846 , first location-determining receiver  62 , second location determining receiver  64 , or attitude and motion module  810 . Further, in addition to the dynamic self leveling of the vehicle, the vehicle height control module  812  or data processor  800  can dynamically adjust the vehicle height  33  commensurate with a crop height for spraying. In another embodiment, the planting depth for planting of seeds in the field can be adjusted by a plating depth adjustment mechanism  509  (in  FIG. 5C ) associated with a planting row unit  212 . In one example, the data processor  800  is adapted to adjust a height of the adjustable legs  12 , via respective actuators  37 , such that a horizontal plane of the central body  10  of the vehicle is level, with respect to the ground, based on sensor data from a motion sensor  846 , an accelerometer, a set of accelerometers, a gyroscope, an inertial measurement unit, or an inertial measurement unit associated with a location-determining receiver ( 62 ,  64 ). In another example, the vehicle height control module  812  or data processor  800  automatically changes the vehicle height by adjusting the adjustable legs  10 , via corresponding actuators  37 , responsive to crop height (e.g., observed crop height), plant maturity, or the time difference between the planting date and the current date of the crop when the vehicle is active in the field, which can be detected via sensors or imaging devices (e.g., stereo imaging device), or which may be entered via a user interface (e.g., keypad, touch screen, keyboard, pointing device and/or display) coupled to the data bus  802  or data ports  832 . In one configuration, the time difference can be determined automatically by a clock and calendar application in the data storage device  804 . 
     Each adjustable leg  12  supports the central body  10 . An arm assembly  14  has a first end  16  and a second end  18  opposite the first end  16 . The first end  16  is pivotably coupled the central body  10  and the second end  18  coupled to a support beam  21  via a frame  19 . A plurality of nozzle assemblies  20  is supported from the support beam  21 . An arm actuator  22  (e.g., hydraulic cylinder or linear actuator) is mounted to or between an arm ( 24 ,  26 ) and the central body  10  or otherwise arranged to control a transverse position of the support beam  21  and the nozzle assemblies  20  with respect to a reference point on the central body  10 , such that each nozzle  20  assembly may be aligned with or directed toward a row of seeds or plants. As used in this document, the arm actuator  22  may be referred to as lateral implement actuator, where spraying, planting or another implement is coupled to the arm assembly  14 . 
     In one embodiment, the pivotable arm assembly  14  comprises first arm  24 , second arm  26 , vertical rods  25 , collars  27  and optional frame  19 . For example, the pivotable arm assembly  14  comprises a first arm  24  (e.g., a first set of first arms) and a second arm  26  (e.g., a second set of second arms), where the first arm  24  is spaced apart and generally parallel to the second arm  26 . The first arm  24  is associated with vertical rods  25  that interconnect an upper first arm and lower first arm. The first arm  24  and vertical rods  25  are connected by fasteners or welded together, for example. Similarly, the second arm  26  is associated with vertical rods  25  that interconnect an upper second arm and lower second arm. The second arm  26  and vertical rods  25  are connected by fasteners or welded together, for example. The vertical rods  25  can rotate about a vertical axis  30  with respect to collars  27 , such as an upper collar and a lower collar that is associated with frame  19 , of the implement, or the support beam  21 . As illustrated in  FIG. 1 , the frame  19  is secured to the support beam  21 . Additional collars  27  are secured to the central body  10  of the vehicle  11 . 
     The first arm  24  and the second arm  26  each have a primary pivot point  28  about a generally vertical axis  30  of the vertical rods  25  within the respective collars  27  near the central body  10 . The first arm  24  and the second arm  26  each have a secondary pivot point  32  about a generally vertical axis of the vertical rods  25  within the respective collars  27  near the support beam  21 . For example, the first arm  24 , the second arm  26 , and the support beam  21  form three sides of a substantially trapezoidal structure  34 , or a substantially parallelogram structure. Further, the fourth side of the trapezoidal structure  34  can be optionally formed by a side of the central body  10 . As used in this document, references to a substantially trapezoidal structure shall be defined to include a parallelogram structure as a subset of trapezoidal structures. 
     As illustrated in  FIG. 2 , the central body  10  covers a tank  36 , such as a generally cylindrical tank, for holding a crop input, a fluid to be pumped or pressurized fluid, such as anhydrous ammonia. The crop may have an optional input port  51  with a cap that can be removed to fill the tank  36 . Crop input or fluid refers to fertilizer, fungicide, pesticide, insecticide, herbicide, nitrogen, potassium, phosphorus, minerals, nutrients, soil amendments, chemicals or other agronomic treatments for plants, seeds, roots or soil. The tank  36  can hold a pressurized fluid or fluid to be pumped by a pump  39 . In one configuration, the central body  10  has central hollow region  40  associated with its lower side  38 , and wherein the central hollow region  40  is adapted to receive removably a tank  36  for holding fluid, such as a crop input to be sprayed or a seed to be planted. 
     A plurality of supply lines  42  and tubes  61  are arranged to supply the respective nozzle assemblies  20  with a pumped or pressurized fluid from the tank  36  or a pump associated with the tank  36 . The vertical supply lines  42 , tubes  61  and/or conduit are illustrated in  FIG. 1 . A manifold  44  coupled to the vertical supply lines  42  distributes, switches or directs the pumped or pressurized fluid to one or more nozzles  48  of each nozzle assembly  20  or to the entire nozzle assembly  20 . The manifold  44  may include one or more valves, such as electromechanical valves or solenoid operated valves for controlling the flow of pumped or pressurized fluid to respective nozzles  48  or nozzle assemblies  20 . For example, in one configuration each nozzle assembly  20  includes a pair of nozzles  48  facing in opposite directions 
     As illustrated in  FIG. 1 , a pair of tactile arms  50  extends (e.g., inwardly) from respective pair of adjustable legs  12 . Each tactile arm  50  is capable of pivoting, flexing or bending about a generally vertical axis near a corresponding adjustable leg  12 . In one embodiment, a magnet  52  is secured to or embedded in each tactile arm  50 . A magnetic field sensor  54  is spaced apart from the tactile arm  50  for generating tactile signal or tactile data representative of the position of the tactile arm  50  versus time in response to contact of the tactile arm with one or more plants in a row or the absence of one or more plants in a row. A vehicle on-board computer  56 , data processor  800 , or control system  801  is programmed for determining a position of the central body  10  or vehicle  11  with respect to one or more plants in a row based on the generated tactile signal or tactile data. 
     In one configuration, the central body  10  has a first side  58  (e.g., front) and a second side  60  (e.g., rear) spaced apart from the first side  58  by a fixed known distance. In one embodiment, a first location-determining receiver  62  is associated with or near the first side  58  on the top of the vehicle  11 ; a second location determining receiver  64  is associated with or near the second side  60  on top of the vehicle  11 . The first location-determining receiver  62 , alone or together with second location-determining receiver  64  is configured to determine a position or angular orientation in the horizontal plane of the Earth of the vehicle or central body  10  with respect to a reference angle, such as magnetic North. For example, the first location-determining receiver  62 , the second location-determining receiver  64 , or both may comprise a satellite navigation receiver, such as global navigation satellite system receiver (GNSS) or Global Positioning System (GPS) receiver, where the satellite navigation receiver may have a wireless receiver for receiving a correction signal, such as a differential correction signal or a precise point positioning (PPP) signal. In one embodiment, the location-determining receivers ( 62 ,  64 ) may be supplemented with additional or supplemental sensors, such as dead-reckoning sensors, odometers, gyroscopes, accelerometers, tilt, roll and yaw sensors, and/or inertial measurement unit (IMU) to facilitate determination of position or angular orientation in conjunction with the location-determining receivers ( 62 ,  64 ). 
     In one embodiment, the support beam  21  extends in a transverse direction  65  that is generally perpendicular to a longitudinal axis  67  of the central body  10  in a forward direction of travel  66  of the vehicle. 
     Each adjustable leg  12  terminates in a rotatable track assembly  68  (e.g. rotatable with respect to the vertical axis  30  and rotatable with respect to a horizontal axis associated with driving the track or belt) or rotatable wheel, if the track assembly  68  is rotatable with respect to the vertical axis to steer the vehicle, an actuator (e.g., hydraulic actuator) or electric motor is used at or above two or more track assemblies  68 , such that a stator (of the electric motor or actuator) is associated with an upper portion of the leg  12  and rotor (of an electric motor or actuator) is coupled to a lower portion of the leg  12  or the respective tracked assembly. In some configurations, the track assembly  68  may be referred to as a tracked wheel, a continuous track or a tank tread. Each track assembly  68  is independently drivable or rotatable by a drive unit  70 , such as an electric motor or a hydraulic motor. Further, in some configurations, the vehicle can be steered (e.g., differentially steered) by applying differential rotational energy (e.g., different rotational velocities) to the ground with respect to different track units. The differential steering can change the heading of the vehicle in accordance with commands from a vehicle guidance module  806  that are provided to the steering controller  822  via data port  832 . 
       FIG. 4A  is side of view of a track assembly as viewed along reference line  4 - 4  of  FIG. 1 . In accordance with  FIG. 4A , each adjustable leg  12  terminates in a track assembly wherein each track assembly comprises an outer belt  72  or linked chains that forms a track or tread that can move or turn the vehicle with respect to the ground. 
     In one configuration, a track assembly comprises one or more of the following: an outer belt  72  or linked chain, a drive wheel  74 , idler wheels  76 , tensioner wheels  78 , and an idler actuator  80  (e.g., air bag, pneumatic or hydraulic cylinder, or linear motor). The idler actuator  80  may be referred to as a track actuator or track footprint actuator. A drive wheel  74  (e.g., a cogged drive wheel or drive pulley) is associated with a rotational energy source or drive unit  70 , such as an electric motor or hydraulic motor, the drive wheel  74  engaging with an inner surface  82  of the outer belt  72 . A pair of idler wheels  76  (e.g., cogged idler wheels or idler pulleys) engages the inner surface  82  of the belt for rotating with the belt. A lower support  84  is arranged to support the idler wheels  76 , where the idler wheels  76  are rotatable with respect to the lower support  84 . An upper hub  86  is configured to support the drive wheel  74 , where the drive wheel  74  is rotatable with respect to the upper hub  86 . An idler actuator  80  extends between the lower support  84  and the upper hub  86  to adjust the tread area or longitudinal dimension of the tread in contact with the ground. Tensioner wheels  78  are pivotably mounted to the upper hub  86  for rotation about corresponding tensioner pivot points  88  in a generally horizontal axis. The tensioner wheels  78  are resiliency biased to maintain a target tension on the outer belt  72  against the drive wheel  74 , the idler wheels  76  and the tensioner wheels  78 . 
     In one embodiment, the tensioner wheels  78 , or both the tensioner wheels  78  and the idler wheels  76 , can pivot about pivot points  88  and optional secondary pivot points  99 , which rotatably connect the levers ( 91 ,  93 ) of the lever assembly  90 . The secondary pivot points  99  are shown as optional by the dashed lines. 
     In an alternate embodiment, the levers ( 91 , 93 ) are fastened together with one or more fasteners (e.g., at or near optional secondary pivot point  99 ) that do not permit the lever  91  to rotate with respect to the lever  93 , such that the entire lever assembly  90  pivots about pivot point  88 . 
     In one embodiment, track assembly  68  may comprise an optional resilient member  73  (e.g., elastomer), a pressurized shock absorber, a spring or an adjustable torsion bar for the target tension on the outer belt  72 . The optional resilient member  73  may be located between the upper hub  86  and the lever assembly  90  (e.g., arms or levers  91 ,  93 ) as indicated by the dashed lines. For example, the resilient member  73  or the spring can be compressed by a threaded rod with a mechanical linkage that connects to the spring (e.g., between different coil portions of a coil spring) for adjustment of the target tension. Although the wheels are shown as pulleys, the wheels may be substituted for sprockets, cogs or cogged wheels, particularly where the belt is replaced by a chain, or linked member. 
     In an alternate embodiment, the track assembly  68  may be associated with an accumulator hydraulically coupled to a hydraulic cylinder as actuator  80 , where the accumulator can store pressurized hydraulic fluid in hydraulic communication with the pressurized side of the hydraulic cylinder to provide resilient biasing of the idler wheels  76 , the tensioner wheels  78 , or both. 
     As illustrated in  FIG. 4B , as the idler actuator  80  increases in height or length  97 , the idler wheels  76  are pushed or forced downward (e.g., as indicated by arrows  96 ). Because of the lever assembly  90  or lever frame between the idler wheels  76  and the tensioner wheels  78 , the tensioner wheels  78  can pivot or rotate upward about their respective pivot points  88  associated with the upper hub  86  (e.g., as indicated by arrows  98 ) and optionally about secondary pivot points  99 . In one embodiment, the lower support  84  has respective slots  83  (e.g., curved slot) that slidably engage corresponding axles  85  of the idler wheels  76  to support rotation of the lever assembly  90  about one or more respective pivot points  88  and optionally about secondary pivot points  99 . For example, if the idler actuator  80  increases its height or length to a maximum, that may coincide with the axle  85  engaging an upper limit of its corresponding slot  83 . The tensioner wheels  78  keep the track tensioned to the target tension level and decrease the longitudinal track length  92 , along or parallel to a longitudinal axis  67  of the vehicle or decrease the track surface area (e.g., longitudinally adjustable track contact area  94  in  FIG. 4C ) in contact with the ground as illustrated in  FIG. 4B . 
     As illustrated in  FIG. 4C , as the idler actuator  80  decreases in height or length  97 , it lets the idler wheels  76  move upward about their respective pivot points  88  associated with the upper hub  86  (e.g., as indicate by arrow  196 ). Because of the lever assembly  90  or lever frame between the idler wheels  76  and tensioner wheels  78 , the tensioner wheels  78  rotate downward (e.g., as indicated by arrow  196 ). In one embodiment, the lower support  84  has respective slots  83  (e.g., curved slot) that slidably engage corresponding axles  85  of the idler wheels  76  to support rotation of the lever assembly  90  about one or more respective pivot points  88  and optionally about secondary pivot points  99 . For example, if the idler actuator  80  decreases its height or length to a minimum, that may coincide with the axle  85  engaging a lower limit of its corresponding slot  83 . The downward movement or rotation keeps the track tensioned as well as increasing and maximizing the overall track length  92  (e.g., longitudinally adjustable track contact area  94 ) in contact with the ground. 
     In one embodiment, an on-board computer  56  or data processor of the vehicle can adjust the footprint, track length  92  or contact area  94  of the track assembly in contact with the ground on a dynamic basis as the vehicle moves through a field or other off-road work site. For example, the on-board computer  56 , data processor  800  or operator of the vehicle can interact with a user interface or controls to use a greater surface area or maximum footprint of the track assembly  68  when the vehicle is moving in a straight line. Conversely, the on-board computer  56  or data processor  800  or operator of the vehicle can adjust the track assembly  68  to a lesser surface area of longitudinally adjustable track contact area  94 , lesser track length of longitudinal track length  92 , or minimum footprint of the track assembly in contact with the ground when turning the vehicle, to minimize the contact surface area when trying to steer a track, especially at zero or low velocity. Reducing the contact surface area (e.g., longitudinally adjustable track contact area  94 ) of the track assembly  68  during turning minimizes the power required to turn the track and maximizes the traction and floatation when needed as well. 
     Further, in an alternate embodiment, the on-board computer  56  or data processor  800  of the vehicle can adjust the footprint or longitudinally adjustable track contact area  94  of the track assembly to maximize the surface area in contact with the ground, consistent with  FIG. 4C , to minimize the soil compaction by increasing or maximizing the aggregate or total surface area of the set of track assemblies  68 . Decreasing soil compaction can be correlated with increased crop yields, healthier root development of plants, reduced expenses for soil cultivation, and possibly reduced soil erosion associated with any reduction in required soil cultivation. 
     Each adjustable leg  12  has a cross section selected from a substantially circular cross section, a substantially elliptical cross section, a substantially rectangular cross section, or a substantially polygonal cross section. In one embodiment, each adjustable leg  12  is hollow and has an actuator  37  located coaxially within the corresponding adjustable leg  12 , wherein the actuator is a hydraulic actuator or a linear motor. In one embodiment, the actuator body of the actuator has radial holes or axial holes (e.g., threaded holes) for receiving fasteners to secure the actuator to a first portion of the leg  12 ; a movable, retractable rod end of the actuator is secured to a second portion of the leg by a mounting flange (e.g., radially extending mounting flange in a substantially horizontal plane), where the first portion and the second portion of the leg  12  are coaxially aligned and telescopically movable with respect to each other to adjust the height of each leg  12 . Accordingly, based on operator input to a user interface or controls or plant height sensors (e.g., ultrasonic plant height sensors, scanning laser, LIDAR (e.g., light detection and ranging), or optical plant height sensors), the on-board computer  56  can adjust the height of the vehicle by adjusting, collectively or in tandem, the height of the legs  12 . For example, the on-board computer  56  can dynamically adjust the height of the vehicle during a spraying operation to clear the leaf canopy, average or maximum height of plants within the field to avoid damage to the plants. 
       FIG. 5A  is a perspective top, front and side view of the vehicle  111  configured with planting row units  212 . In accordance with one embodiment, a vehicle platform  11  comprises a central body  110  where adjustable legs  12  extend downward from the central body  110 . Each adjustable leg  12  has a corresponding leg actuator to adjust a respective vertical height of each adjustable leg  12 . Each adjustable leg  12  supports the central body  110 . 
     A set of planting row units  212  are supported by or suspended from the central body  110  by bracket  219  via one or more fasteners. As illustrated in  FIG. 5A , each planting row unit  212  is secured or fastened to support beam  21 . In  FIG. 5A , the vehicle  111  can adjust the lateral position of set of planting row units  212  by adjusting the lateral position of the vehicle  111  to adjust the spacing between the planted rows of seed in adjacent passes or swaths (e.g., parallel swaths) of the vehicle  111  through a field. 
     Each planting row unit  212  comprises an optional leading opener  214  (e.g., opener disc or coulter), a planting opener  227  (e.g., planting disc), or opener assembly ( 214 ,  227 ) for opening the soil or forming a furrow or groove in the soil. The planting row unit  212  further comprises a planting unit  216  for planting seed in the opened soil, such as the furrow or groove in the soil, and a closer  218  for closing or covering seed with soil, such as covering the furrow or the groove in the soil. The closer  218  may comprise one or more closing wheels to cover the seeds, close the soil over and around the seeds, or the firm the soil as the planting unit  216  progresses through the field. The planting unit  216  may refer to the combination of a planting opener  227 , seed tube  224  and associated seed outlet (e.g., or another seed delivery mechanism), and a gauge wheel  225  that is associated with the planting opener  227  (e.g., an opener disc, coulter, knife or cutting member). The gauge wheel  225  comprises a depth wheel that establishes a depth of the planted seed in the soil, furrow or groove in the soil with respect to the surface of the surrounding soil or undisturbed soil elevation above a bottom the furrow or groove. Although the gauge wheel  225  may be mounted forward, rearward or in line (e.g., concentrically or eccentrically) with the planting opener  111 , as illustrated in  FIG. 5A  the gauge wheel  225  is mounted frontward with respect to the planting opener. The gauge wheel  225  can be mounted or secured to the planting row unit  212  to provide a fixed planting depth or an adjustable planting depth, where  FIG. 5B  and  FIG. 5C  show gauge wheel  225  with an illustrative depth adjustment mechanism for adjusting the planting depth in greater detail. 
     In one configuration, the opener  214  and the planting opener  227  can be configured as coulters, which are stationary or rotatable. The planting row unit comprises a bin  220  for holding seed. The bin  220  is coupled to a seed metering unit  222  for controlling the rate of seed provided to a seed outlet (e.g.,  507  in  FIG. 5C ) associated with or near a planting opener (e.g., planting opener). The seed metering unit  222  can be fed with seeds by gravity from the bin  220 , for example. In an alternate embodiment, each of the seed bins  220  for respective row units  212  may be optionally pneumatically fed from bulk seed storage container in or on the central body  212 . In one configuration, the planting row units  212  are placed laterally apart from each other to simultaneously plant multiple rows of seeds at once. 
     As in  FIG. 1 , the central body  110  has a first side  58  and a second side  60  spaced apart from the first side  58  by a fixed known distance, wherein a first location-determining receiver  62  is associated with the first side  58  and wherein a second location-determining receiver  64  is associated with the second side  60 . The first location-determining receiver  62 , alone or together with second location-determining receiver  64  is configured to determine a position or angular orientation in the horizontal plane of the Earth of the vehicle or central body  110  with respect to a reference angle, such as magnetic North. 
     As illustrated, each adjustable leg  12  terminates in a track assembly or wheel. Each track assembly  68  is independently drivable or rotatable by a drive unit  70 , such as an electric motor or a hydraulic motor. The track assembly of  FIG. 1 ,  FIG. 5A , and  FIG. 5B  can be identical. Like reference numbers in  FIG. 1 ,  FIG. 5A  and  FIG. 5B  indicate like elements. 
       FIG. 5B  is perspective view of yet another embodiment of the vehicle  211  configured with planting row units  212 . The vehicle  211  is similar to vehicle  111 , except the vehicle  211  has a pivotable arm assembly  14  for lateral adjustment of the set of row units  212 . The pivotable arm assembly  14  is coupled between the bracket  319  and the support beam  21  to allow lateral adjustment of the support beam  21  and the planting row units  212  secured to the support beam  21 . The pivotable arm assembly  14  has a first end and a second end opposite the first end. The first end is pivotably coupled the bracket  319  or central body  110  and the second end is coupled to the support beam  21 , directly or via frame  19 . In the pivotable arm assembly  14 , the first arm  24 , the second arm  26 , and the support beam  21  form three sides of a substantially trapezoidal structure (or a substantially parallelogram structure) and wherein the fourth side of the trapezoidal structure is optionally formed by a bracket  219  that extends downward from the central body  110 . 
     In one embodiment, the arm actuator  22  has its ends secured between an arm ( 24 ,  26 ) of the pivotable arm assembly  14  and the central body  110  or the bracket  219  to adjust the lateral position of the support beam  21 ; hence, the lateral position of the row units  212  are secured to the support beam with respect to the central body  110 . Accordingly, during adjacent passes or swaths (e.g., parallel swaths) of the vehicle  211  through the field, for the vehicle configuration of  FIG. 5B  and  FIG. 5C , the data processor  800  can adjust the lateral position of adjacent rows of the seeds or plants without laterally moving the track assemblies  68 . Still, just as in  FIG. 5C , the vehicle configuration of  FIG. 5B  and  FIG. 5C  can adjust the lateral position of the vehicle  111  to adjust the spacing between the planted rows of seed in adjacent passes or swaths. An arm actuator  22  is arranged to control a transverse position of the support beam  21  and the planting row units with respect to a reference point on the central body  110 , such that planting row unit  212  may be aligned with a set of target positions for a row of seeds or plants. In one embodiment, the data processor  800  or vehicle guidance module  806  can make lateral adjustment of the planting row units with respect to the vehicle to result in planted rows of seeds or swaths that are substantially parallel to each other or that track a target path plan, such as linear row segments, contour row segments, curved row segments and/or spiral row segments that are stored in a data storage device  804 . 
       FIG. 5C  is a side view of an enlarged portion of  FIG. 5B  within rectangular area labeled  5 , as indicated by the dashed lines. In one embodiment, the gauge wheel  225  has an adjustable planting depth for the planting opener  227  and the seed tube  224 . The gauge wheel  225  can be mounted in front of the planting opener  227  or to the rear of the planting opener  227 , such as trailing the seed tube  224  and seed tube outlet  507 . In one configuration, the planting opener  227  is mounted on a support  500  that extends downward from frame or support structure  503 ; a vertex end  508  of forked arm  501  (e.g., V-shaped arm) can rotate about a pivot point  502  associated with the support  500 , a first distal end  504  of the forked arm  501  is associated with (e.g., supports the rotation of) the gauge wheel  225  and a second distal end  506  of the forked arm  501  is associated with a depth actuator or depth adjustment mechanism  509 . The depth adjustment mechanism  509  comprises one or more of the following: threaded rod, a threaded bolt, a manual adjustment mechanism, a depth actuator, a linear actuator, a linear motor, electrohydraulic cylinder, or electric motor with its rotor coupled to the screw, and electric motor with its rotor coupled to the threaded bolt. If the threaded bolt, threaded rod or manual adjustment mechanism is used without an electric motor, a user of the vehicle can manually adjust the planting depth of seeds when the vehicle is stationary, whereas if the threaded rod  511  is driven by an electric motor  510 , the data processor  800  can automatically and dynamically adjust the planting depth by sending a data message or signal to the depth adjustment mechanism  509  (e.g., depth actuator) via the data ports  832 . In  FIG. 5C , the motor  510  is indicated in dashed lines to show it is optional. In one embodiment, the depth adjustment mechanism  509  (e.g., depth actuator) is coupled between the second distal end  506  of the forked arm  501  (e.g., at a female threaded bore that can pivot about a substantially horizontal axis via a pin that engage a bore in the forked arm  501 ) and the support  500  and can adjust the distance between the second distal end  506  of forked arm  501  and support  500  to rotate the forked arm with respect to the pivot point  502 ; hence, the gauge wheel  225  about a pivot point  502  associated with a forked arm  501 . 
       FIG. 6  is a front perspective view of an alternate embodiment of a vehicle  311  which illustrates legs  12  with rectangular cross-sections. Although the adjustable leg  12  of  FIG. 6  has a generally rectangular a cross section in  FIG. 6 , in alternate embodiments the adjustable leg  12  may have a cross section selected from a substantially circular cross section, a substantially elliptical cross section, a substantially rectangular cross section, or a substantially polygonal cross section. In one embodiment, hollow adjustable legs (e.g.,  12 ) have telescopic or coaxial, telescopic alignment to support vertical height adjustment. For example, in one configuration, each adjustable leg (e.g.,  12 ) is hollow and has an actuator  137  located coaxially within the corresponding adjustable leg, wherein the actuator is a hydraulic actuator  137  or a linear motor. As illustrated in  FIG. 6 , an output shaft of internal combustion engine  602  is coupled to hydraulic pump  604 . Further the hydraulic pump  604  provides pressurized hydraulic fluid via hydraulic lines  603  to the hydraulic actuators  137  for height adjustment in each leg  12  and for driving a drive unit  70 , such as hydraulic motor or hydraulic actuator (e.g., near hub  86 ), at each tracked assembly  68  via hydraulic lines  603 . 
       FIG. 7  is a perspective view of another alternate embodiment of the vehicle  711  which illustrates a framework  701  of a sprayer boom implement that can support nozzle assemblies  20 , such as a set of nozzles  48  or Y-drop set of nozzles. In one embodiment, a vehicle platform  711  comprises a central body  210  and a set of adjustable legs  12  extending downward from the central body  210 . Each adjustable leg  12  has a corresponding leg actuator to adjust a respective vertical height of each adjustable leg  12 , Each adjustable leg  12  supports the central body  210 . 
     An arm assembly  14  has a first end  16  and a second end  18  opposite the first end  16 . The first end  16  is pivotably coupled to the central body  110  via vertical rods  25  and collars  27  that rotatably engage the vertical rods  25 . The collars  27  are connected to the central body  210  or its frame. Similarly, the second end  18  is pivotally coupled to a framework  701  via vertical rods  25  and collars that rotatably engage the vertical rods. The collars are connected to the framework  701  directly, or via framework  19 , which is secured to the framework  701 . A plurality of nozzle assemblies  20  is supported from the framework  701 . An arm actuator is arranged for controlling a transverse position of the framework and the nozzle assemblies with respect to a reference point on the central body  210 , such that each nozzle assembly may be aligned with a row of seeds or plants. In one embodiment, the framework  701  comprises a center or intermediate section  705  that supports a first outer section  703  and a second outer section  707 . The first outer section  703  and the second outer section  707  are wing structures that have hinges or joints to fold upward with respect to the intermediate section  705 . In an alternate embodiment, additional outer sections  709  may be attached rotatably to the framework  701  (e.g., at hinges) to provide additional lateral coverage or swath width for one pass of the vehicle  711 . 
     In the embodiments disclosed in this document, a vehicle may comprise an autonomous robotic machine that is capable of applying fertilizer, herbicides, pesticides, seeds, or other crop care inputs both prior to crop planting and emergence as well as after crop emergence. The vehicle platform or vehicle can be configured as a light weight vehicle that is well-suited for reduced soil compaction during field operations, by eliminating the weight of a cab for the human operator and operator. For many configurations, the robotic machine can sheds the weight of climate control systems, infotainment systems and various operator controls associated with the cab. In some configurations, the tracked assemblies of the vehicle can provide less than 5 pounds per square inch (PSI) ground pressure or even as low as 3 PSI ground pressure in certain configurations. Accordingly, nitrogen can be applied to crop at critical times, even when the soil structure would not normally allow field entrance because of concerns over soil compression or damage. Further, the use of the vehicle could eliminate the need for primary tillage; hence, improving soil health, microbial activity, and earthworm population. 
     The embodiments of the vehicle disclosed in this document support travel in any direction via the innovative track assembly with or without the dynamically adjustable ground contact area (e.g., contact area  94 ), For example, each leg  12  can support rotation (e.g., up to 180 degrees) of the tracked assembly  68  about a vertical axis and/or differential rotation of one or more track assemblies. 
     If the orthogonal orientations of the vehicles are configured to have different track widths between adjacent track assemblies that are transverse to the direction of travel (e.g., direction of travel  66 ), the track widths of the vehicle can be changed by simply rotating the vehicle 90 degrees with respect to an initial or original travel direction via the track assemblies, provided that the spraying implement or the planting row units can be rotated, similarly, or turned off while the vehicle adjusts its position in a 90 degree orthogonal transit mode. 
     The vehicle is well suited for improved or simplified headland management practice of a field by steering of the track assemblies to attain a 90 degrees rotation of the vehicle from headland to the central or main portion of the field. The 90 degrees of rotation may be more readily and accurately achieved without steering error associated with conventional Ackerman steering systems, for example. 
     Each embodiment of the vehicle can be configured to raise and lower the body to clear crop, adjust to side hill operation to maintain a level body via independent leg adjust, and to lower down to replace, exchange or pick up a full liquid tank (e.g., tank  36 ), dry product, planter, or other mounted attachment as necessary. For a side hill, one or more legs  12  may have different heights (e.g., relative to ground) than other legs to maintain a level body of the vehicle. The removable tank connection could be done via a job box, where this job box is a proprietary self-connection mechanism to vehicle and contains all required inputs for a particular job or task. 
     The job box can include chemicals, seed, fertilizer, batteries, fuel, oil, sensors, tools, or any other input required for that task. The task could be defined as a specific job for a specific amount of time and area. The vehicle can support dispersing a job or agricultural task among multiple machines within a field or multiple fields to perform a job via swarm technology. 
       FIG. 8A  and  FIG. 8B  (collectively  FIG. 8 ) are a block diagram of a control system for the autonomous or remote-controlled vehicle. In one embodiment, the control system comprises a data processor  800 , a data storage device  804 , and data ports  832  that are coupled to a data bus  802 . The data processor  800 , data storage device  804 , and data ports  832  can communicate with each other via the data bus  802 . 
     In one embodiment, the data processor  800  comprises a microcontroller, a microprocessor, a programmable logic array, a logic device, an arithmetic logic unit, a digital signal processor, an application specific integrated circuit, or another electronic device for inputting, outputting, processing or manipulating data. The data storage device  804  may comprise electronic memory, nonvolatile random access memory, a magnetic storage device, a magnetic disc drive, an optical storage device, an optical disc drive, or another suitable storage device or medium. The data ports  832  may comprise a transceiver, the combination of a transceiver and buffer memory, or a transmitter and a receiver, for example. 
     The data storage device  804  can support electronic modules, store software instructions or support data modules, such as one or more of the following: a vehicle guidance module  806 , a row sensor module  808 , an attitude and motion module  810 , a vehicle height control module  812 , a lateral implement control module  814  (e.g., for lateral position shifting of the implement), a row unit control module  816  and a track control module  818 . 
     In one embodiment, the vehicle guidance module  806  accesses, creates or receives a path plan to guide the vehicle along a target path in performing spraying, planting or another task in one or more fields. The target path may be defined by three dimensional geographic coordinates, way points, linear segments, curved segments, linear equations, or quadratic equations that describe the target path or target positions of the vehicle. For example, the target path plan may track a back-and-forth pattern with end row turns that covers substantially an entire area of a field within boundaries that define the field. 
     The vehicle guidance module  806  receives position data, motion data, and attitude data (e.g., yaw or heading) from the first location-determining receiver  62 , the second location-determining receiver  64 , the row sensor  54 , the motion sensors  846 , or the attitude and motion module  810 . For example, buffer memory  834  may store observed (e.g., time-stamped) position data, motion data, and attitude data (e.g., yaw or heading) from the first location-determining receiver  62 , the second location-determining receiver  64 , row sensor  54 , and/or the motion sensors  846  for communication via the data ports  832  to the data processor  800  or any module or modules within the data storage device  804 . The vehicle guidance module  806  generates command data or command signals to send steering commands to the steering controller  822  to track the path plan, target heading or target yaw. In turn, the steering controller  822  communicates with the steering system  820 , such as an electrohydraulic steering system or an electrical steering system. In one example, the steering system  820  comprises an electric motor that drives one or more tracks, where the direction of the vehicle can be controlled by differential steering with respect to the tracks to steer or direct the vehicle in accordance with a target heading provided by the vehicle guidance module  806  or data processor  800 . In another example, the steering system  820  comprises an actuator that rotates a portion, such as bottom portion of a respective leg  12  about a vertical axis to steer or direct the vehicle in accordance with a target heading provided by the vehicle guidance module  806  or data processor  800  consistent with a path plan to cover a field or area with a crop input. 
     The vehicle guidance module  806  can send command data or command signals to the steering controller  822 , the braking controller  826 , and the propulsion controller  830  via one or more data ports  832  or via the vehicle data bus  831  such that the vehicle tracks a path plan. A braking controller  826  is coupled to a braking system  824 , such as an electrohydraulic braking system, an electrical braking system or a mechanical braking system. The braking controller  826  is coupled to a data port  832 . A propulsion controller  830  is coupled to a propulsion unit  828 , such as one more electric drive motors, an internal combustion engine, or an internal combustion engine that provides rotational mechanical energy to a generator or an alternator that provides electrical energy to one or more electric drive motors. The propulsion controller  830  is coupled to a data port  832 . 
     The attitude and motion module  810  can estimate any of the following: (1) the attitude, including the roll, pitch and yaw angles of the vehicle for a sampling interval, (2) yaw rate of change for a sampling interval, and (3) the motion parameters of the vehicle, such as ground speed, velocity and acceleration for a sampling interval based on measurements or observations of the first location-determining receiver  62 , the second location determining receiver  64  an any motion sensors  846 . For example, the motion sensors  846  may comprise one or more accelerometers, a gyroscope, an inertial measurement unit, an inertial measurement unit of a location-determining receiver, or a set of accelerometers associated with multiple orthogonal axes. 
     The row sensor module  808  may be used to process tactile sensor readings associated with a row sensor for sensing a row of plants or crop. For example, the row sensor may comprise one or more tactile arms  50  with corresponding magnets  52  secured to or within the tactile arms  50 . A respective magnetic field sensor  54  is positioned proximately to the magnets  52  to detect magnetic field measurements (e.g., variations in the observed magnetic fields associated with the magnets  52 ) when the arms  50  strike, are deflected from, or interact with the presence of absence of a row of plants. As illustrated in  FIG. 1 , the tactile arms  50  are associated with a corresponding row of plants (not shown), and a single row unit, nozzle or nozzle assembly of the vehicle. The row sensor module  808  can provide an indication as to whether the vehicle is laterally aligned with respect to one or more rows of plants and can accordingly provide a lateral offset to adjust alignment of the vehicle with respect to row of plants. The row sensor  54  may provide an analog data signal to an analog-to-digital converter  836 , which in turn provides a digital signal to row sensor module  808  for processing, via the buffer memory  834  or data ports  832 . The row sensor module  808  is not used if the vehicle is used for planting, as opposed to spraying one or more existing rows of plants or crop. 
     Although a pair of tactile arms  50  are associated with the adjustable legs  12 , in an alternate embodiment multiple pairs of tactile arms  50  can be used or suspended from the implement support beam  21  or vertical supply lines  42  to align with multiple corresponding rows of plants, for example. 
     The vehicle height control module  812  receives attitude data, such as the roll, tilt and yaw angles, for the vehicle from the first location-determining receiver  62 , the second location-determining receiver  64 , from the motion sensors  846 , or from the attitude and motion module  810 . The vehicle height control module  812  can send control signals or control data messages to the vehicle height actuators  37  (e.g., hydraulic cylinders) associated with or within each leg of the vehicle to maintain a level attitude of the vehicle or an attitude that tracks or mimics the attitude of the terrain or land over which the vehicle travels. 
     In one embodiment, the vehicle height control module  812  can adjust the vehicle height or height of one or more legs to accommodate an appropriate boom height or sprayer bar height that is commensurate with the plant height of the plants to be sprayed to avoid damaging of the plants and to properly apply the crop treatment (e.g., fertilizer, pesticide, insecticide, or herbicide). In another embodiment, the row unit control module  816  or data processor  800  can send a signal or data message to the height adjustment mechanism  509  (e.g., height actuator) to facilitate planting of seeds to a proper target depth and to maintain proper tracking (e.g., avoiding undesired draft steering from interaction of the opener ( 214 ,  227 ) with the ground) of a target guidance path, such as target A-B guidance line between points A and B, or contour guidance line. 
     In one embodiment, the lateral implement control module  814  receives lateral position data of a sprayer nozzle with respect to one or more plant rows from the row sensor module  808  or a target offset of the lateral position between the plant row and the sprayer nozzle to achieve proper application of crop treatment to one or more plant rows. Further, the lateral implement control module  814  can generate a control signal or data message to cause the arm actuator  22  to move the support beam  21  and associated nozzles  48  laterally for alignment with one or more plant rows or a target offset with respect to one or more plant rows. 
     In one configuration, the row unit control module  816  can activate, deactivate or adjust the spray characteristics of one or more nozzles of the vehicle based on the a prescription plan or agronomic plan for applying crop inputs or treatments to the plants, where the prescription plan may vary based on zones within a field or work area. For example, the row unit control module  816  can send a signal or data message to the manifold  44  or a row unit controller  844 ; the manifold  44  can activate one or two nozzles of each row unit, where the manifold may comprise one or more electrohydraulic valves. In one configuration, the row unit controller  844  comprises a nozzle valve controlled by a valve actuator, such as servo motor. In another configuration, the row unit controller  844  comprises a planter row unit controller to activate or control one or more planting row units  212 . 
     For a remote-controlled control system, an optional user interface  850  may be coupled to the data port  832  via an optional wireless link  852 , such as a pair of wireless transceivers. The user interface  850  may comprise a display, keypad, touch screen display, keyboard, pointing device, or another device to support an operator remotely controlling the vehicle ( 11 ,  111  or  211 ). The user interface  850  and the wireless link  852  are shown in dashed lines to indicate they are optional. 
       FIG. 9  describes an illustrative example of how the track control module  818  operates in the second mode or during track turn assist mode to send control signals or control data messages to one or more track idler actuators or idler actuators  80  via the data ports  832 . 
       FIG. 9  is flow chart of method for controlling a track assembly of the autonomous or remote-controlled vehicle. In one configuration, the data processor  800  is adapted to dynamically adjust a track contact area in contact with the ground in response to observed vehicle ground speed with respect to a threshold speed and an observed yaw rate change with respect to a threshold yaw rate change. The method of  FIG. 9  begins in step S 901 . 
     In step S 901 , the data processor  800 , the vehicle guidance module  806 , or the track control module  818  activates a track-turn-assist mode (e.g., second mode) that can dynamically adjust the track contact area (e.g., or longitudinal contact length  92 ,  94 ) in contact with die ground on one or more tracked assemblies  68  associated with corresponding adjustable legs  12  (e.g., vertically adjustable) of the vehicle. In one embodiment, the track control module  818  operates in a first mode or a second mode. In a first mode, the track control module  818  does not assist or adjust the footprint or track contact area of the track in contact with the ground to assist turning of the vehicle in accordance with a target heading or target yaw. The data processor  800 , vehicle guidance module  806  or the track control module  818 , or vehicle operator (if any) may select or program the first mode if the field conditions are wet, slippery or otherwise can benefit from full or maximum contact area of the footprint of the track with the ground. In a second mode, the track control module  818  assists or adjusts the footprint of the track or track contact area in contact with the ground to assist turning of the vehicle in accordance with a target heading or target yaw. 
     In step S 902 , the track control module  818  or the electronic data processor  800  determines if the vehicle velocity is greater than or equal to a velocity threshold. If the vehicle velocity is greater than or equal to the velocity threshold, the method continues with step S 904 . However, if the vehicle velocity is not greater than the velocity threshold or is less than the velocity threshold, the method continues with step S 903 . For instance, the velocity threshold is set to assure that the track assist mode or second mode results in proper turning of the vehicle and does not result in binding or sticking of the track contact area with respect to the ground. 
     In step S 903 , the track control module  818  or the data processor  800  waits for an interval prior to returning to step S 902 . 
     In step S 904 , the track control module  818  or the data processor  800  determines whether the observed yaw rate change is greater than or equal to a yaw rate change threshold. For example, the first location-determining receiver  62 , the second location-determining receiver  64 , the motion sensors  846 , and/or the attitude and motion module  810  may provide the observed yaw rate change, whereas the yaw rate change threshold may comprise a user-definable setting, a factory setting, or an empirical setting based on field studies. In one example, the yaw rate change threshold is set to determine if the vehicle is changing its heading more than approximately ten degrees within a corresponding time period or sampling interval, where approximately means a tolerance of plus or minus about ten percent. If the observed yaw rate change is greater than or equal to the yaw rate change threshold, then the method continues with step S 905 . However, if the observed yaw rate change is not greater or equal to the yaw rate threshold, the method continues with step S 903 . 
     In step S 905 , the track control module  818  or data processor  800  observes or estimates the current track footprint of one or more tracked assemblies  68  with respect to a minimum track footprint (e.g., minimum longitudinal track length  92  or minimum track contact area) and maximum track footprint (e.g., maximum longitudinal track length  94  or maximum track contact area). For example, the track control module  818  or data processor  800  observes or estimates whether or not the current contact area of the track in contact with the ground is a minimum contact area or a maximum contact area based on the position of an actuator in one or more tracked assemblies, or based on a position sensor associated with a corresponding actuator in a respective tracked assembly. 
     In step S 906 , the track control module  818  or the data processor  800  determines whether or not a current track footprint or track contact area is minimized or not. If the current track footprint is minimized or if the track contact area in contact with the ground is at a minimum contact area, then the method continues with step S 908 . However, if the current track footprint is not minimized, the method continues with step S 907 . 
     In step S 907 , the track control module  818  or the data processor  800  decreases the track footprint or track contact area of one or more track assemblies  68  with the ground to a minimum track contact area (e.g., minimum level or minimum longitudinal track length  92 ) until the observed yaw rate change is less than the yaw rate change threshold. 
     Step S 907  may be carried out in accordance with one or more techniques that may be carried out separately and cumulatively. Under a first technique, the data processor  800  is adapted to reduce or minimize the track contact area in contact with the ground for a time period if the vehicle ground speed is greater or equal to a velocity threshold, if the yaw rate change is greater than or equal to the yaw rate change threshold, and if the current track contact area is not minimized. Under a second technique, the time period of the minimized track contact area is limited to a time period until the yaw rate change is less than the yaw rate change threshold. Under a third technique, once the observed yaw rate change is less than the yaw rate change threshold, the track contact area may be restored to the previous setting prior to any decrease in the track footprint or track contact area initiated in step S 907 . After step S 907 , the method may return to step S 901 , for instance. 
     In step S 908 , the track control module  818  or the data processor  800  maintains a minimum level or minimum track contact area of the track footprint until the observed yaw rate change is less than the observed yaw rate change threshold. Step S 908  may be carried out in accordance with various techniques, which may be applied separately or cumulatively. Under a first technique, once the observed yaw rate change is less than the yaw rate change threshold, the track control module  818  or the data processor  800  can be programmed to revert or change the track contact area with respect to the ground to the maximum contact area or maximum footprint of the respective tracked assembly. Under a second technique, once the observed yaw rate change is less than the yaw rate change threshold, the track control module  818  or the data processor  800  can be programmed to revert or change the track contact area in contact with the ground to an average, mean or medium contact area or an average, mean or medium footprint of the respective tracked assembly. 
     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.