Patent Publication Number: US-10315652-B2

Title: System and method of a velocity control mechanism for a vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional to U.S. application Ser. No. 14/885,630 filed on Oct. 16, 2015, the content of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to a vehicle including a velocity control mechanism. 
     SUMMARY 
     In one aspect, the disclosure provides a velocity control mechanism operable to control a vehicle at a maximum forward velocity setting and a maximum rearward velocity setting. The velocity control mechanism includes a processor configured to receive a first signal from an actuator selectively positionable in a velocity control mode in which the vehicle operates at a maximum limited forward velocity less than the maximum forward velocity setting and a maximum limited rearward velocity less than the maximum rearward velocity setting. The first signal represents a desired vehicle forward velocity. The processor is also configured to control a velocity of the vehicle in the forward direction based on the first signal and receive a second signal from the actuator. The second signal represents a desired vehicle rearward velocity. The processor is further configured to control a velocity of the vehicle in the rearward direction based on the second signal. 
     In another aspect, the disclosure provides a velocity control mechanism for a vehicle operable to move in a forward direction and a rearward direction. The velocity control mechanism includes a first forward slot in which an actuator is moveable to control a forward acceleration of the vehicle and a first rearward slot parallel to the first forward slot. The actuator is moveable within the first rearward slot to control a rearward acceleration of the vehicle. The velocity control mechanism also includes a side slot orthogonal to the first forward and rearward slot. The actuator is moveable within the side slot to control the vehicle at a forward determined velocity. The velocity control mechanism further includes a second forward slot parallel to the first forward slot and in communication therewith by a passageway. The actuator is moveable within the second forward slot to control a forward velocity of the vehicle. The velocity control mechanism includes a second rearward slot parallel to the first rearward slot and in communication therewith by the passageway. The actuator is moveable within the second rearward slot to control a rearward velocity of the vehicle. 
     Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a vehicle including a velocity control mechanism according to an embodiment of the disclosure. 
         FIG. 2  is a perspective view of the velocity control mechanism located within a cab of the vehicle of  FIG. 1 . 
         FIG. 3  is a top view of the velocity control mechanism of  FIG. 2  including a joystick. 
         FIG. 4  illustrates a graph of a relative position of the joystick of  FIG. 3  in response to a force acting on the joystick. 
         FIG. 5  illustrates a graph of a relative position of the joystick of  FIG. 3  and a velocity of the vehicle. 
         FIG. 6  illustrates a method of operation of the velocity control mechanism. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of supporting other embodiments and of being practiced or of being carried out in various ways. 
       FIG. 1  illustrates a vehicle  10  operable to move in a forward direction  15  or a rearward direction  20  by a prime mover  25  driveably coupled to wheels  30 . In the illustrated embodiment, the vehicle  10  is an agricultural tractor; however, the vehicle  10  described herein is not limited in its application to agricultural tractors and may be associated with other vehicles. For example, the vehicle  10  may be earth moving vehicles, construction vehicles, snow removal vehicles, sand moving vehicles, forestry harvesting vehicles, cargo moving vehicles, mining vehicles, on highway vehicles, automotive vehicles, etc. In other embodiments, the wheels  30  may be continuous tracks providing traction to the vehicle  10 . 
     The illustrated prime mover  25  may include any power source to provide rotational driveline power to the wheels  30 . For example, the prime mover  25  may include, but is not limited to, an internal combustion engine, a piston engine, a rotary engine, a hydraulic motor, a hydrostatic system, an electric motor, etc. In some embodiments, a transmission  35  is driveably coupled between the prime mover  34  and the wheels  30  to provide a mechanical gear reduction therebetween. The illustrated prime mover  25 , the wheels  30 , and the transmission  35  are operable to move the vehicle  10  at a determined velocity either in the forward direction  15  or the rearward direction  20 . In the illustrated embodiment, the maximum forward velocity is about 50 kilometer per hour (km/hr), and the maximum rearward velocity is about 30 km/hr. In other embodiments, the maximum forward velocity is about 40 km/hr and the maximum rearward velocity is about 20 km/hr. 
     With reference to  FIGS. 1 and 2 , a velocity control mechanism  40  is located within a cab  45  of the vehicle  10 . The illustrated velocity control mechanism  40  includes a control processor  42  and is operable to control a velocity of the vehicle  10  in the forward direction  15  or the rearward direction  20  as well as to control the vehicle  10  into a stopped or immobile state. In particular, the velocity control mechanism  40  is coupled to a command seat or control console  50  with the seat  50  rotatable such that the seat  50  can face the forward direction  15  or the rearward direction  20 . In other embodiments, the velocity control mechanism  40  may be located elsewhere in the cab  45  separate from the command seat  50  such that the velocity control mechanism  40  does not move relative to the command seat  50 . In addition, the velocity control mechanism  40  is positioned adjacent other controls (e.g., a hitch control, a selective control valve (SCV), a power take-off (PTO), etc.) located within the cab  45 . In the illustrated embodiment, an accelerator pedal  60 , which is operable to control acceleration and velocity of the vehicle  10 , and a brake pedal  55 , which is operable to control deceleration of the vehicle  10 , are also located in the cab  45 . 
     With reference to  FIG. 3 , the velocity control mechanism  40  includes an actuator  65  (e.g., a lever or joystick) selectively positionable within a pathway  70  in the form of an aperture within a portion of the control console  50  defining an acceleration control mode  75  and a velocity control mode  80 . The illustrated acceleration control mode  75  includes a first forward recess, slot, or gate  85 , a first rearward gate  90  parallel with the first forward gate  85 , and a side gate  95  perpendicular to the gates  85 ,  90 . An intermediate control mode  100  is defined by a passageway  105  and is located between the first forward gate  85 , the first rearward gate  90 , and the side gate  95  and is also parallel with the side gate  95 . In the illustrated embodiment, the joystick  65  is biased into the intermediate control mode  100 , at a position illustrated in  FIG. 3 , by a biasing member (e.g., a spring). An operator can move the joystick  65  out of the position illustrated in  FIG. 3  by overcoming a detent mechanism (not shown) surrounding the joystick  65 . 
     The illustrated passageway  105  provides communication between the acceleration control mode  75  (i.e., the first forward gate  85 , the first rearward gate  90 , and the side gate  95 ) and a second forward gate  110  and a second rearward gate  115  associated with the velocity control mode  80 . As such, the intermediate control mode  100  is located between the acceleration control mode  75  and the velocity control mode  80 . In the illustrated embodiment, the second forward gate  110  is parallel to the first forward gate  85  with the first forward gate  85  extending further from the passageway  105  than the second forward gate  110 , and the second rearward gate  115  is parallel to the first rearward gate  90  with the first rearward gate  90  extending further from the passageway  105  than the second rearward gate  115 . 
     A primary forward detent mechanism  120  is positioned near an end of the first forward gate  85  away from the intermediate control mode  100 , and a primary rearward detent mechanism  125  is positioned near an end of the first rearward gate  90  away from the intermediate control mode  100 . In the illustrated embodiment, the detent mechanisms  120 ,  125  are non-latching detents that provide positive feedback when the joystick  65  engages the detent mechanisms  120 ,  125 . In addition, a limited forward detent mechanism  130  is positioned at or near an end of the second forward gate  110  adjacent the passageway  105 , and a limited rearward detent mechanism  135  is positioned at or near an end of the second rearward gate  115  adjacent the passageway  105 . The detent mechanisms  130 ,  135  are similar to the detent mechanisms  120 ,  125  in that the detent mechanisms  130 ,  135  provide positive feedback when the joystick  65  engages the detent mechanisms  130 ,  135 . 
     With reference to  FIGS. 2 and 3 , an adjustment mechanism  140  is partially enclosed within the joystick  65  such that two portions (one of which is shown in  FIG. 2 ) opposite from each other are configured to be gripped by the operator. In the illustrated embodiment, the adjustment mechanism is an encoder wheel rotatable about an axis  145 . In other embodiments, the adjustment mechanism  140  may be located on a top surface of the joystick  65 . In further embodiments, the adjustment mechanism  140  may be linearly translatable relative to the joystick  65 . 
     In operation, the operator of the vehicle can manipulate the joystick  65  within the acceleration control mode  75  to control acceleration, and ultimately a velocity, of the vehicle  10  in the forward direction  15  or the rearward direction  20 . In particular, a position of the joystick  65  within the acceleration control mode  75  is conveyed to the processor  42  to control acceleration of the vehicle  10 . By moving the joystick  65  into the first forward gate  85  towards the detent mechanism  120 , the vehicle  10  accelerates in the forward direction  15  at a set acceleration rate programmed within the processor  42 . Thus, any position of the joystick  65  within the first forward gate  85  will accelerate the vehicle  10  at the set acceleration rate. In the illustrated embodiment, the processor  42  is programmed with three different forward acceleration rates to which the operator can select between. For example, a switch may be located on the joystick  65  or the control console  50  to select between the three different acceleration rates. In other embodiments, the processor  42  may be programmed with more or fewer than three acceleration rates. If the operator releases the joystick  65  within the first forward gate  85 , the joystick  65  biases back into the intermediate control mode  100  at the position illustrated in  FIG. 3 , and the vehicle will remain at a velocity reached during acceleration prior to releasing the joystick  65 . 
     A maximum forward velocity of the vehicle  10  is selected when the joystick  65  engages the detent mechanism  120 , illustrated as joystick  65 A in  FIG. 3 . In one embodiment, the maximum forward velocity is selectively programmed into the processor  42  such that the operator can select one of a plurality of maximum velocities. In other embodiments, the maximum forward velocity may be the absolute maximum velocity of the vehicle  10 , or the maximum forward velocity may be a determined maximum forward velocity suitable for a specific terrain (e.g., hilly, bumpy, incline, etc.). In the illustrated embodiment, the detent mechanism  120  conveys manual feedback to the operator when the joystick  65 A reaches the maximum forward velocity. If the operator releases the joystick  65 A after engaging the detent mechanism  120 , the joystick  65 A biases back into the intermediate control mode  100  at the position illustrated in  FIG. 3 , but the vehicle  10  will continue to accelerate at the set acceleration rate until the maximum forward velocity is reached. At any time during operation, the operator can actuate the brake pedal  55  to override the velocity control mechanism  40 , which decelerates the vehicle  10  into the immobile state. However, the vehicle  10  will again accelerate once the brake pedal  55  is released and the joystick  65  positioned within the first forward gate  85 . 
     The side gate  95  is operable to maintain a forward set point velocity of the vehicle  10 . Stated another way, when the joystick  65  is moved into the side gate  95 , illustrated as joystick  65 B in  FIG. 3 , the vehicle  10  will accelerate or decelerate to and hold at a predetermined velocity, similarly to an automotive cruise control mechanism. The forward set point velocity is adjustable by the operator. In the illustrated embodiment, the joystick  65 B is biased back into the intermediate control mode  100  at the position illustrated in  FIG. 3  once released, but the vehicle  10  is maintained at the forward set point velocity. In other embodiments, the joystick  65 B is not biased into the intermediate control mode  100  once the operator releases the joystick  65 B within the side gate  95 . Rather, the joystick  65 B is maintained in the side gate  95  until the operator moves the joystick  65 B back into the intermediate control mode  100 . 
     By moving the joystick  65  into the first rearward gate  90  towards the detent mechanism  125 , the vehicle  10  accelerates in the rearward direction  20  at a set acceleration rate selected by the operator, similar to moving the joystick  65  into the first forward gate  85  as discussed above. In the illustrated embodiment, the processor  42  is programmed with three different rearward acceleration rates between which the operator can select. If the operator releases the joystick  65  within the first rearward gate  90 , the joystick  65  biases back into the intermediate control mode  100  in the position illustrated in  FIG. 3  and the vehicle will remain at a velocity reached during acceleration prior to releasing the joystick  65 . In other embodiments, the processor  42  may be programmed with more or fewer than three acceleration rates. At any time during operation, the operator can actuate the brake pedal  55  to override the velocity control mechanism  40 . However, the vehicle  10  will again accelerate once the brake pedal  55  is released and the joystick  65  positioned within the first rearward gate  90 . 
     In addition, the operator can stop the vehicle by manipulating the joystick  65  within the acceleration control mode  75 . For example, by moving the joystick  65  into the first forward  85  and releasing the joystick  65  to be biased into the position illustrated in  FIG. 3 , the vehicle  10  will travel at a set velocity in the forward direction  15 , as described above. If the operator then moves the joystick  65  to engage the detent  125 , illustrated as joystick  65 C in  FIG. 3 , and again releases the joystick  65 C to be biased back into the position illustrated in  FIG. 3 , the vehicle  10  will decelerate to a stop. A similar operation is performed if the vehicle  10  is accelerating in the rearward direction  20  and the operator moves the joystick  65  into engagement with the detent  120 . 
     It is advantageous to directly control a velocity of the vehicle  10  (rather than controlling an acceleration of the vehicle  10  to reach a desired velocity) to increase accuracy and manipulation while the vehicle  10  is moving. For example, the vehicle  10  may be selectively attached to an auxiliary implement, which may include a trailer attached to a hitch of the vehicle  10 , a hydraulic loader bucket attached to a front portion of the vehicle  10 , etc. While moving the vehicle  10  into alignment with the auxiliary implement to be attached thereto, the operator decreases the velocity of the vehicle  10  while approaching the auxiliary implement. 
     The velocity control mode  80  provides direct velocity control to the vehicle  10  compared to controlling an acceleration of the vehicle  10  via the acceleration control mode  75 . By moving the joystick  65  along the passageway  105  of the intermediate control mode  100  away from the side gate  95 , the joystick  65  is positioned to enter into the second forward gate  110  or the second rearward gate  115 . To enter the second forward gate  110 , the joystick  65  engages and moves past the detent mechanism  130  providing the operator positive feedback such that the operator does not inadvertently enter the second forward gate  110 . 
     With reference to  FIG. 4 , a user must apply a threshold force  150  to the joystick  65  to enter the second forward gate  110  or the second rearward gate  115 . In the illustrated embodiment, the threshold force  150  is substantially the force associated with moving the joystick  65  past the detent mechanisms  130 ,  135 . A position of the joystick  65  within the second forward gate  110  or the second rearward gate  115  is illustrated by a percent of position away from the intermediate control mode  100 . In the illustrated embodiment, the threshold force  150  is about 2.5 Newtons (N) or about 0.5 pounds-force (lbf); however, in other embodiments, the threshold force  150  may be greater than or less than 0.5 lbf. Once the threshold force  150  is exceeded, the force to move the joystick  65  linearly increases. In other embodiments, the force required to move the joystick  65  after the threshold force  150  is exceeded may increase in a different matter (e.g., quadratically). 
     With reference to  FIGS. 5 and 6 , a method  155  of controlling a velocity of the vehicle  10  via the velocity control mechanism  40  is illustrated. Moving the joystick  65  from the intermediate control mode  100  to the velocity control mode  80  (step  160 ) will align the joystick  65  with the second forward gate  110  and the second rearward gate  115 . By moving the joystick  65  into the second forward gate  110  (step  165 ) and overcoming the threshold force  150 , the vehicle  10  moves in the forward direction  15  at a velocity proportional to a position of the joystick  65  within the second forward gate  110 . In particular, the velocity control mechanism  40  controls a velocity of the vehicle  10  by conveying a signal to the processor  42  representing a relative position of the joystick  65  within the velocity control mode  80  (step  170 ). In the illustrated embodiment, an absolute velocity of the vehicle  10  when the joystick  65  is within the velocity control mode  80  spans from the immobile state of the vehicle  10  to a maximum limited velocity setting of about 2 km/hr. The maximum limited velocity setting is less than the maximum velocity of the vehicle  10 . In the illustrated embodiment, the maximum limited velocity setting is determined within the processor  42 . In other embodiments, the maximum limited velocity setting may be less than 5 km/hr. The maximum limited velocity setting is reached when the joystick  65  is positioned at an end of the second forward gate  110  away from the detent mechanism  130 , illustrated as joystick  65 D in  FIG. 3 . The illustrated relationship between a velocity of the vehicle  10  and a relative position of the joystick  65  within the second forward gate  110  is non-linear (e.g., a quadratic relationship) to increase resolution at lower velocities. In other embodiments, the relationship between a velocity of the vehicle  10  and a relative position of the joystick  65  within the second forward gate  110  may be different (e.g., a linear relationship). 
     The adjustment mechanism  140  is operable to increase or decrease (e.g., expand or contract) a range of velocities as illustrated in  FIG. 5 . For example, by rotating the adjustment mechanism  140  in a first direction, a signal is conveyed to the processor  42  and the maximum limited velocity setting (e.g., 2 km/hr) increases, and if the adjustment mechanism  140  is rotated in a second direction opposite from the first direction, a signal is conveyed to the processor  42  and the maximum limited velocity setting decreases. In the illustrated embodiment, the adjustment mechanism  140  can increase the maximum limited velocity setting to about 5 km/hr. However, once the joystick  65  is released and biased into the intermediate control mode  100  at the position illustrated in  FIG. 3 , the maximum limited velocity setting defaults back to the original maximum limited velocity setting (e.g., 2 km/hr). 
     If the operator releases the joystick  65  after entering the second forward gate  110 , the joystick  65  biases back into the intermediate control mode  100  thereby stopping the vehicle  10 . Alternatively, the operator can actuate the brake pedal  55  to override the velocity control mechanism  40 . However, the vehicle  10  will return to a velocity proportional to the position of the joystick  65  within the second forward gate  110  once the brake pedal  55  is released. 
     By moving the joystick  65  into the second rearward gate  115 , the vehicle  10  moves in the rearward direction  20  at a velocity proportional to a position of the joystick  65  within the second rearward gate  110 , as illustrated within  FIG. 5 . In particular, a signal is conveyed to the processor  42  to control a velocity—in the rearward direction  20 —of the vehicle  10 . The maximum limited velocity setting is reached when the joystick  65  is positioned at an end of the second rearward gate  115  away from the detent mechanism  135 , as illustrated as joystick  65 E in  FIG. 3 . If the operator releases the joystick  65  after entering the second rearward gate  115 , the joystick  65  biases back into the intermediate control mode  100  thereby stopping the vehicle  10 . Alternatively, the operator can actuate the brake pedal  55  to override the velocity control mechanism  40 . However, the vehicle  10  will return to a velocity proportional to the position of the joystick  65  within the second rearward gate  115  once the brake pedal  55  is released. 
     The operator can also change direction (e.g., either in the forward direction  15  or the rearward direction  20 ) of the vehicle  10  by moving the joystick  65  from the acceleration control mode  75  to the velocity control mode  80 . In particular, the operator moves the joystick  65  from the first forward gate  85  to the second rearward gate  115  and maintains the joystick  65  within the second rearward gate  115 . As such, the vehicle  10  will stop from moving and accelerating in the forward direction  15  and will then move in the rearward direction  20  at a velocity associated with a position of the joystick  65  within the second rearward gate  115 . However, if the operator releases the joystick  65  from the second rearward gate  115  into the intermediate control mode  100  before the vehicle  10  comes to a stop, the vehicle  10  will accelerate in the rearward direction  20  until the same velocity is reached before entering the second rearward gate  115 . A similar operation will occur if the operator moves the joystick  65  from the first rearward gate  90  into the second forward gate  110  to change direction from the rearward direction  20  to the forward direction  15 .