Abstract:
A motorcycle including a frame, an engine mounted to the frame, and a stand movable between an extended position in which the stand supports the motorcycle and a retracted position. The motorcycle includes a sensor operable to generate a stand signal indicative of at least one of the extended and retracted positions of the side stand and a controller electrically coupled to the sensor to receive the stand signal. The controller is programmed for preventing operation of the engine based on the stand signal during a first operating condition of the motorcycle and is further programmed to allow running of the engine during a second operating condition of the motorcycle, regardless of the stand signal.

Description:
BACKGROUND 
   The present invention relates to motorcycle stands and electronic interlocks for use therewith. More specifically, the invention relates to an intelligent control system for selectively shutting off or preventing starting of the engine based on an operating condition of the motorcycle. 
   SUMMARY 
   In one embodiment, the invention provides a motorcycle including a frame, an engine mounted to the frame, and a stand movable between an extended position in which the stand extends outward and is operable to support the motorcycle and a retracted position in which the stand is retracted inward. The motorcycle further includes a sensor operable to generate a stand signal indicative of a position of the side stand and a controller electrically coupled to the sensor to receive the stand signal. The controller is programmed for preventing operation of the engine based on the stand signal during a first operating condition of the motorcycle and is further programmed to allow running of the engine during a second operating condition of the motorcycle, regardless of the stand signal. 
   In another embodiment, the invention provides an interlock circuit for a motorcycle having a frame, an engine mounted to the frame, a transmission coupled to the engine, and a stand movable between an extended position for supporting the motorcycle and a retracted position. The interlock circuit includes a sensor operable to generate a stand signal indicative of the position of the stand and a controller electrically coupled to the sensor to receive the signal. The controller is programmed for preventing operation of the engine based on the stand signal during a first operating condition of the motorcycle and is further programmed to allow running of the engine during a second operating condition of the motorcycle, regardless of the stand signal. 
   In yet another embodiment, the invention provides a method of operating a motorcycle having an engine, a transmission, and a stand, which supports the motorcycle in an extended position and is movable to a retracted position. The method includes sensing a position of the stand and sensing an operating condition of the motorcycle. The engine is prevented from operating based on a sensed position of the stand when the motorcycle is in a first operating condition. The engine is allowed to operate regardless of a position of the stand when the motorcycle is in a second operating condition. 
   Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a motorcycle with a side stand and a stand interlock circuit according to one embodiment of the invention; 
       FIG. 2  is an enlarged perspective view of the side stand of the motorcycle of  FIG. 1  in the extended position; 
       FIG. 3  is a perspective view of the side stand of the motorcycle of  FIG. 1  in the retracted position; 
       FIG. 4  is a schematic diagram of the stand interlock circuit; and 
       FIG. 5  is a flow diagram illustrating logic states and events occurring in the stand interlock circuit. 
   

   Before any embodiments of the invention are explained in detail, it is to be understood that the invention 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 invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
   DETAILED DESCRIPTION 
     FIG. 1  illustrates a motorcycle  10  having a frame  14 , a front wheel  18 , a rear wheel  22 , and an engine  26 . The motorcycle  10  also includes a side stand  30  for supporting the motorcycle  10  in an upright position during periods of non-use. In other embodiments, a center stand (not shown) is included on the motorcycle  10  in addition to or instead of the side stand  30 . The illustrated side stand  30  is attached to the frame  14  for pivoting movement between extended (i.e., “down”) and retracted (i.e., “up”) positions. A spring  32  is coupled to both the side stand  30  and the frame  14  in a position which allows the side stand  30  to be biased by the spring  32  in either of the extended or retracted positions. In the retracted position, the side stand  30  abuts a resilient stop  33  on the frame  14 . 
   As shown in  FIGS. 2 and 3 , the motorcycle  10  includes a stand position sensor  34  near the side stand  30 . The stand position sensor  34  is configured to sense the position of the side stand  30  and output a signal (e.g., an electrical signal) indicative thereof. The side stand  30  is formed with a protruding flange portion  38  configured to be positioned directly in front of the stand position sensor  34  when the side stand  30  is in the retracted position. When the side stand  30  is extended, the flange portion  38  is removed from the line-of-sight of the stand position sensor  34 . Thus, when the side stand  30  is in the retracted position, the stand position sensor  34  senses the presence of the flange portion  38 , and when the side stand  30  is in the extended position, the stand position sensor  34  senses the absence of the flange portion  38 . In alternate embodiments, the side stand  30  is formed without the flange portion  38 , and is configured for interaction with the stand position sensor  34  in a different manner. 
   The stand position sensor  34  is a Hall-effect sensor and operates to sense the presence of the side stand  30  in the retracted position by sensing a magnet or ferrous material of the side stand  30 . The stand position sensor  34  senses at least two conditions: the side stand  30  in the retracted position and the absence of the side stand  30  from the retracted position (which may occur when the side stand  30  is either extended or at least partially out of the retracted position). The stand position sensor  34  sends a signal indicative of the position of the side stand  30  to a controller, such as the engine control module (ECM)  42  ( FIG. 4 ) of the motorcycle  10 . In alternate embodiments, the stand position sensor  34  includes an ultrasonic sensor, an optical sensor, a mechanical switch (e.g., rotary switch), a potentiometer, etc. and may be configured to output a signal indicative of the position of the side stand  30  including positions between the retracted and extended positions. 
   The stand position sensor  34  and the ECM  42  are part of a stand interlock circuit  43  illustrated in  FIG. 4 . The stand interlock circuit  43  also includes a neutral switch or gear position sensor  44  to send a signal “TRANS” to the ECM  42  indicative of a state of a transmission of the motorcycle  10  (at least detecting between neutral and non-neutral i.e., “in-gear” states). The motorcycle  10  also includes a vehicle speed sensor  45  as part of the stand interlock circuit  43 . The vehicle speed sensor  45  sends a signal “VEHSPD” to the ECM  42  indicative of the motorcycle&#39;s speed. The ECM  42  also monitors the state of a run/stop switch, or kill switch  49 . 
     FIG. 4  illustrates a portion of the stand interlock circuit  43  including the ECM  42 , an instrument panel  46 , and a turn signal module (TSM)  50 . The TSM  50  controls the operation of the motorcycle&#39;s turn signals, and also routes signals “IGN” and “TRANS” respectively from an ignition switch  52  and the gear position sensor  44  through one or more signal communication wires, such as a serial data cable, or “bus”  54  to the ECM  42 . The “IGN” signal is indicative of the position of the ignition switch  52 , either start/run or off. The kill switch  49  sends a “RUN/STOP” signal to the ECM  42  indicative of its position, either start/run or off. When the engine  26  is running and either the kill switch  49  is moved from the start/run position to the off position or the ignition switch  52  is moved from the start/run position to the off position, the ECM  42  ceases normal operation of the fuel injectors  56  and ignition coil  57  to stop the operation of the engine  26 . Under certain circumstances, as discussed below, a “STAND” signal from the stand position sensor  34  to the ECM  42  causes the ECM  42  to stop the engine  26  in the same manner. The instrument panel  46  includes an indicator such as a message display  58  for selectively informing the rider of the stand interlock circuit status, among other things, according to parameters discussed below. 
     FIG. 5  is a logic diagram illustrating the function of the stand interlock circuit  43  as it interacts with the motorcycle  10  throughout a range of conditions. The logic states in boxes  100 ,  102 , and  104  represent three states that can occur prior to starting the engine  26 . In the first state, illustrated by box  100 , the ignition switch  52  is in the start/run position (as is the kill switch  49  of  FIG. 4 ) and the side stand  30  is retracted. The bus  54  is in-tact and communicating properly with the ECM  42 , as indicated by a “BUS” signal. The ECM  42  is programmed to allow the engine  26  to be started when the start button is pushed, regardless of the “TRANS” and “VEHSPD” signals (i.e., the stand interlock circuit  43  does not prevent the engine  26  from starting based on the transmission state or the vehicle speed). When the start button is pushed from the state of box  100 , the engine  26  is started (unless some other system of the motorcycle prevents starting) and the motorcycle  10  enters the state of box  106 . 
   From box  106 , the motorcycle  10  is set to launch as the stand interlock is “inactive” (i.e., the stand interlock does not prevent operation of the engine  26 ). The stand interlock is inactive at all times that the side stand  30  is retracted and the signal from the stand position sensor  34  indicates the same to the ECM  42 . Thus, when the rider puts the transmission into gear, the motorcycle  10  can be operated and ridden normally, as represented by box  108 . 
   If, during operation of the motorcycle  10  (from box  108  of  FIG. 5 ), the rider disengages the clutch without shifting the transmission to neutral, and then brings the motorcycle  10  to a stop, extending the side stand  30  to the extended position (or the side stand  30  is out of the retracted position at least enough to be sensed absent by the stand position sensor  34 ), an interlock violation occurs, as represented by box  110  of  FIG. 5 . Because the side stand  30  is extended with the transmission in-gear (i.e., not in a neutral state, even though the clutch is disengaged) and the motorcycle  10  stopped, the ECM  42  is programmed to shut down the engine  26  and report the interlock violation to the rider via the instrument panel  46 , such as by a text message “SIDE STAND” on the message display  58 . The operation of the engine  26  is therefore prevented. As used herein, “preventing operation” of the engine  26  includes stopping the engine  26  from a running condition and also preventing starting of the engine  26  from an off or dormant state. 
   The transmission being in-gear and the motorcycle  10  being stopped is referred to herein as a first operating condition of the motorcycle  10 . When the side stand  30  is sensed by the stand position sensor  34  to be extended during the first operating condition of the motorcycle  10 , an interlock violation occurs. The motorcycle  10  is in an operating condition other than the first operating condition any time that the motorcycle is not stopped and/or the transmission is in the neutral state. The ECM  42  is programmed to monitor and analyze the operating condition of the motorcycle  10  and prevent operation of the engine  26  (e.g., by control of the fuel injectors  56  and the ignition coil  57 ) when an interlock violation occurs. 
   For the purposes of the invention, a “VEHSPD” signal indicative of a speed at or below a predetermined upper limit or threshold, such as 15 km/hr is also considered to be a “stopped” condition of the motorcycle  10  in that the stand interlock circuit  43  will respond the same as if the motorcycle  10  was absolutely stationary. In other embodiments, the stand interlock circuit  43  considers the motorcycle  10  stopped when the “VEHSPD” signal is at or below a different predetermined upper limit or threshold, such as 20 km/hr or zero km/hr. 
   The state of the transmission is not necessarily affected by whether or not a clutch of the motorcycle  10  is disengaged. For example, the transmission can be in the neutral state when the clutch is engaged i.e., coupling the engine  26  and the transmission. Conversely, the transmission can be in the non-neutral state i.e., “in-gear” even when the clutch is disengaged. In alternate embodiments, the “TRANS” signal is indicative of whether or not the engine  26  is drivingly coupled to the rear wheel  22 , such that the signal sent to the ECM  42  depends on the state of the transmission and/or the state of the clutch of the motorcycle  10 . In such embodiments, an additional sensor may be used to monitor the state of the clutch. 
   Returning now to the pre-operation states, the second starting state is illustrated by box  102 . In this state, the ignition switch  52  is in the start/run position (as is the kill switch  49  of  FIG. 4 ), the side stand  30  is extended, the transmission is in neutral, and the motorcycle  10  is stopped (i.e., speed is at or below the predetermined threshold). The bus  54  is in-tact and communicating properly with the ECM  42 . When the start button is pushed, the engine  26  starts and the stand interlock circuit  43  enters the pending interlock state of box  112  (i.e., the motorcycle  10  is not set for launch). Lifting the side stand  30  to the retracted position and then shifting the transmission into gear will put the motorcycle  10  in operation (from box  112  to  106  to  108 ). However, shifting the transmission into gear without first lifting the side stand  30  will cause an interlock violation (box  110 ) and the engine  26  automatically shuts off. 
   The third pre-operation state is illustrated by box  104 . In this starting state, the ignition switch  52  is in the start/run position (as is the kill switch  49  of  FIG. 4 ), the side stand  30  is extended, the transmission is in gear, and the motorcycle  10  is stopped (i.e., speed is at or below the predetermined threshold). The bus  54  is in-tact and communicating properly with the ECM  42 . Because the side stand  30  is extended with the transmission in gear and the motorcycle  10  stopped, the engine  26  is prevented from starting when the start button is pushed. In some embodiments, the engine  26  starts but is shut down immediately. As with the other sequences of events that result in an interlock violation in the stand interlock circuit  43 , preventing engine operation prevents the rider of the motorcycle  10  from making an improper launch of the motorcycle  10  with the side stand  30  extended. The interlock encourages the rider to perform the correct operational sequence of lifting the side stand  30  before starting the engine  26 , or at least before putting the transmission into gear. Under the circumstance that a partially extended side stand  30  is causing an interlock violation, the rider is thus encouraged to perform necessary maintenance on the side stand  30 . 
   At any time during normal operation of the motorcycle  10  (from box  108  of  FIG. 5 ), the rider may stop the motorcycle  10  and shift the transmission to neutral before extending the side stand  30 . Under this condition, the engine  26  continues to run and the stand interlock circuit  43  enters the state of box  112 , in which the interlock status is “pending”. Because the motorcycle  10  is stopped and the side stand  30  is not retracted, interlock violation (box  110 ) and engine shutdown are pending, should the transmission be shifted from neutral into gear. From box  112 , shifting the transmission into gear causes the motorcycle  10  to be in the first operating condition as discussed above, in which engine operation is prevented subject to the position of the side stand  30 . 
   From box  112 , the motorcycle  10  is returned to normal operation by first lifting the side stand  30  (to put the stand interlock circuit  43  into the state of box  106 ) and then shifting the transmission into gear (to enter the state of box  108 ). The engine  26  can be intentionally shut down by the rider at any time from the state of box  108  by switching the ignition switch  52  from the start/run position to the off position, as indicated at the bottom of  FIG. 5 . Although not shown in  FIG. 5 , switching the kill switch  49  from the start/run position to the off position is an alternative way for the rider to intentionally stop the operation of the engine  26 . 
   Another aspect of the invention involves the intelligent function of the stand interlock circuit  43 , represented at the lower portion of  FIG. 5 . If the side stand  30  moves out of the retracted position while the motorcycle  10  is in gear, but not stopped (i.e., the motorcycle  10  is traveling above the predetermined threshold at box  108 ), the engine  26  does not stop. The stand position sensor  34  detects that the side stand  30  is not in the retracted position (box  114 ), but the ECM  42  is programmed to allow continuous operation of the engine  26 . The interlock function is temporarily disabled in this circumstance, and the message display  58  informs the rider of such (box  116 ). For example, the message display  58  shows a text alert, such as “SIDE STAND”. In some embodiments, the interlock function is disabled for the remainder of the trip (i.e., until the engine  26  is restarted). When the interlock function is disabled, the engine  26  is not shut down at any time, under any operating condition due to the position of the side stand  30  and/or the signal sent from the stand position sensor  34  to the ECM  42 . At the operator&#39;s discretion, the engine  26  is stopped (box  118 ), and the stand interlock circuit  43  attains the end state (box  120 ). The stand interlock circuit  43  is refreshed to one of the pre-operation states  100 ,  102 , and  104  when the next starting attempt occurs. 
   The intelligence of the stand interlock circuit  43  allows continued operation of the engine  26  during an operating condition of the motorcycle  10  in which the motorcycle speed is above the predetermined speed, regardless of the state of the transmission and regardless of the position of the side stand  30  and the signal indicative thereof. This allows the rider to continue riding the motorcycle  10  with power from the engine  26  (box  116 ) when the side stand  30  moves out of the retracted position (e.g., due to a worn spring, impact with road debris, etc.). The rider may continue traveling or bring the motorcycle  10  to a controlled stop at a desired time and location. 
   If, at any time, the vehicle speed sensor  45  fails to report a signal to the ECM  42  or reports a signal that is deemed faulty, the “VEHSPD” signal defaults to zero, or “motorcycle stopped”. The stand interlock circuit  43  continues to operate based upon the position of the side stand  30 , the state of the transmission, and the assumption that the motorcycle  10  is stopped. An interlock violation occurs when the side stand  30  is out of the retracted position and the transmission is in-gear. 
   If, at any time, the bus  54  is not communicating the state of the transmission to the ECM  42  or communicates a signal that is deemed faulty, the “TRANS” signal defaults to “in-gear”. The stand interlock circuit  43  continues to operate based upon the position of the side stand  30 , the motorcycle speed, and the assumption that the transmission is in-gear. An interlock violation occurs when the side stand  30  is out of the retracted position and the motorcycle is traveling at or below the predetermined speed. 
   If, at any time, a fault occurs with the stand position sensor  34  (no signal or a not-trusted signal received by the ECM  42 ), the interlock function is temporarily disabled and the engine  26  does not stop at any time, under any operating condition, due to the position of the side stand  30 . The message display  58  informs the rider that the interlock function is disabled by displaying the text alert “SIDE STAND”.