Abstract:
Apparatus, and associated method, for controlling intermittent operation of a windshield wiper assembly. A user interface, formed of a pair of momentary contact switches, is used to set the repetition rate of intermittent operation of a wiper blade and, subsequently, when desired, to terminate the intermittent operation. A first of the switches is actuated two times, with the time period separating the actuations defining the repetition rate of the wiper blade when in the intermittent mode of operation.

Description:
[0001]     The present invention relates generally to an intermittent windshield wiper system having a wiper blade that is caused intermittently to perform a wiping motion at a selected repetition rate. More particularly, the present invention relates to apparatus, and an associated method, that permits a user to select the repetition rate at which the wiper blade performs the wiping motion. Selection of the wiper blade repetition rate is made through use of a single momentary contact switch, or other, input actuator.  
         [0002]     A user is able to select the exact repetition rate by selecting when to actuate, and then re-actuate, the switch. The need to rotate a dial into a dial position and estimate the subsequent repetition rate through positioning of the dial is obviated as the repetition rate is directly selected by selecting when to actuate and re-actuate the momentary contact switch.  
       BACKGROUND OF THE INVENTION  
       [0003]     The use of windshield wipers to clear a vehicular windshield or other vehicular window or surface has been standard since almost the start of the automotive era. A wiper blade, rotatably affixed, or otherwise positioned, at the vehicular surface, is caused to be moved across the surface. The movement of the wiper blade causes rain, snow, ice, and other precipitation to be removed from the surface. Depending upon the amount of precipitation, the motion of the wiper blade across the surface must be repeated, sometimes at regular intervals.  
         [0004]     While very early implementations of windshield wipers required that an operator manually apply the moving forces to cause the movement of the wiper blade across the windshield, or other, surface, pneumatic, and then, electric, actuators were soon used to provide the moving forces. Through use of the pneumatic or electrical motors to provide the moving forces, the operator no longer was required to provide the moving force. Generally, the moving forces provided by the pneumatic actuator or electric motor provide for repeated movement of the wiper blade at a fixed rate.  
         [0005]     The rate of precipitation and the speed of movement of the vehicle are determinative of the frequency, or rate, at which the wiper blade is needed repeatedly to be moved across the windshield, or other, surface to remove the precipitation thereon. Most simply, a single-speed, viz., a simple “on-off”, actuator or motor is used. When single-speed operation is provided, the wiper blade is caused to be moved, repetitively, at a single, fixed rate. Or, the actuator or motor provides more than one fixed rate of operation, e.g., a low-speed rate and a high-speed rate of operation. An operator selects which of the two, or more, fixed speeds at which the actuator or motor causes movement of the wiper blade across the windshield, or other vehicular surface. The speed is selected best to remove the precipitation falling against, or forming on, the surface that is to be cleared.  
         [0006]     Intermittent windshield wiper operation has, in more recent years, also been provided. When in a so-called intermittent mode of operation, the rate at which the wiper blade is caused to be moved across the vehicular surface is less than at the low-speed, fixed rate. Typically more than just a single, additional, low-speed rate at which the wiper blade is movable across the vehicular surface, intermittent operation permits an operator to select any of a range of repetition rates at which the wiper blade moves across the surface.  
         [0007]     Some conventional intermittent wiper systems utilize a rotary dial that contains multiple contacts. User rotation of the dial into a selected dial position is determinative of the selected repetition rate. While the user is able to select the repetition rate through the positioning of the rotatable dial, the user typically is unable to know precisely the selected repetition rate but through a trial-and-error process. That is to say, a user positions the dial in a first position to select an initial repetition rate. And, then the dial is again rotated, to increase or to decrease the repetition rate to obtain a repetition rate that corresponds to the desired repetition rate. Sometimes, multiple iterations of dial rotation are carried out to arrive at the desired repetition rate.  
         [0008]     The conventional capability of merely estimating the repetition rate and then modifying the selected repetition rate until the desired repetition rate is obtained distracts the user, typically the driver of the vehicle, from other driving tasks. Any distraction of the driver when operating the vehicle in inclement weather conditions is potentially hazardous. In addition to the rotatable dial, an additional actuator is typically used, increasing the complexity and cost of the wiper assembly user interface.  
         [0009]     An economical windshield wiper assembly, permitting intermittent operation and having a user interface permitting easier use to obtain the desired repetition rate of the wiper blade, would therefore be advantageous.  
         [0010]     It is in light of this background information related to windshield wiper systems that the significant improvements of the present invention have evolved.  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention, accordingly, advantageously provides apparatus, and an associated method, for an intermittent windshield wiper system having a wiper blade that is caused intermittently to perform a wiping motion at a selected repetition rate.  
         [0012]     Through operation of an embodiment of the present invention, a manner is provided by which to permit a user to select the repetition rate at which the wiper blade performs the wiping motion. A user selects the wiper blade repetition rate through actuation of a single momentary contact switch, or other type of input actuator.  
         [0013]     The user actuates and then re-actuates the switch to select the repetition rate at which the wiper blade is to be caused to perform the wiping motion. The time period between the successive switch actuations sets the repetition rate. Conventional operation, required by a user to select the repetition rate through positioning of a dial into a dial position in which the repetition rate is merely estimated, sometimes requiring the user successively to reposition the dial to obtain the desired repetition rate, is obviated  
         [0014]     In one aspect of the present invention, a momentary contact switch, or other input actuator, is positioned to permit a user, such as a driver of a vehicle, easily to actuate the switch. The user selects intermittent operation of the windshield wiper by actuating the switch two times. The time period separating the successive actuations of the switch determines the rate at which the wiper blade performs the wiping motion. Once the repetition rate is selected, and the user decides to change the repetition rate, the user merely performs the same procedure of actuating and, if necessary, re-actuating, the switch to reselect the repetition rate. Through convenient positioning of the switch and providing an easily-actuatable switch, such as the aforementioned momentary contact switch, the user, when operating a vehicle, is easily able to set the wiper repetition rate. The user is little-distracted from operating the motor vehicle as the actuation of the switch is performable with minimal effort by the user.  
         [0015]     In another aspect of the present invention, a second, momentary contact switch is also provided, positioned also to permit easy access by a user. When intermittent movement of the wiper blade is no longer needed, the user actuates the second switch to cause the intermittent operation to be terminated. Thereby, the user interface comprises merely a pair of momentary contacts switches, or other input actuators, positioned to permit their actuation by a user to set and commence intermittent movement of the wiper blade at a desired repetition rate and to terminate the intermittent movement of the wiper blade.  
         [0016]     In another aspect of the present invention, actuation by the user of the first switch also causes immediate movement of the wiper blade to perform the wiping motion across the vehicular windshield or other surface. And, when the switch is re-actuated, the wiper blade is again caused to perform the wiping motion. Subsequently, automatic wiping motion of the wiper blade is carried out automatically at a repetition rate corresponding to the time period separating the successive actuations of the switch.  
         [0017]     The actuation and re-actuation of the switch must be performed by the operator within a designated period, such as the time-out period of a timer. A timer function, e.g., is provided whose timing period commences with the detection of user actuation of the first switch. When the switch is re-actuated prior to timing-out of the timer, the repetition rate of intermittent operation of the wiper blade to perform the wiping motion is set. If, conversely, the user fails to re-actuate the switch within the time-out of the timer, the intermittent operation does not commence. Instead, the timer resets, and the subsequent re-actuation, if any, of the switch, causes the timing function to restart timing. If the user subsequently again actuates the switch prior to timing out of the timing function, the repetition rate is set and automatic, intermittent operation of movement of the wiper blade commences.  
         [0018]     In one implementation, the momentary contact switches, or other input actuators, are connected to a controller and to a timer. The actuation of the first switch causes timing of the timer to commence and causes the controller to generate a control signal to operate a wiper motor to impart forces causing the wiping motion of the wiper blade. If the first input actuator is again actuated prior to timing out of the timer, the time period between the successive actuations of the switch defines the time period between successive wiping motions of the wiper blade subsequently to be performed automatically. That is to say, the repetition rate of the intermittent operation of the wiper blade corresponds to the time period between the successive actuations of the switch. To terminate the intermittent operation of the motion of the wiper blade, the user actuates the second switch. The actuation of the second switch is detected by the controller, and the controller causes a wiper motor no longer to impart the driving force to cause motion of the wiper blade. If the wiping motion of the wiper blade is partially completed when the user actuates the second switch, the wiper motor causes the wiper blade to complete its wiping motion and then terminates further wiping motions.  
         [0019]     In a further implementation, additional overrides are provided to provide for fixed, non-intermittent operation of the wiper blade in a manner that overrides the selection of the intermittent operation.  
         [0020]     In these and other aspects, therefore, apparatus, and an associated method, is provided for user control of intermittent movement of a wiper blade of a vehicular windshield wiper. A first actuator is actuable by the user to request movement of the wiper blade. A timer is adapted to receive indications of actuation of the first actuator. The timer is configured to determine a time period between successive actuations of the first actuator. A wiper blade movement controller is adapted to receive indications of actuation of the first actuator and of the time period determined by the timer. The wiper blade movement controller is configured selectably to cause intermittent movement of the wiper blade at a rate responsive to the time period determined by the timer.  
         [0021]     A more complete appreciation of the present invention and the scope thereof can be obtained from the accompanying drawings that are briefly summarized below, the following detailed description of the presently-preferred embodiments of the present invention, and the appended claims.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]      FIG. 1  illustrates a functional block diagram of the apparatus of an embodiment of the present invention.  
         [0023]      FIG. 2  illustrates a state diagram representative of an embodiment of the present invention.  
         [0024]      FIG. 3  illustrates a process diagram representative of the process carried out pursuant to an embodiment of the present invention.  
         [0025]      FIG. 4  illustrates a method flow diagram representative of the method of operation of an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0026]     Turning first to  FIG. 1 , windshield wiper control apparatus, shown generally at  10 , is provided to permit a user to select, and control, intermittent operation of a windshield wiper  12 . In the exemplary implementation, the windshield wiper  12  is positioned at a vehicular windshield  14 , and the control apparatus controls the intermittent wiping operation of the wiper blade in directions indicated by the arrow  16  thereacross. More generally, the windshield  14  is representative of any surface, such as a back window or light fixture surface, of a structure. And, the wiper blade  12  is representative of any wiper blade positionable upon any of such surfaces.  
         [0027]     The apparatus  10  is functionally represented, implementable, in any desired manner, including, in part, by algorithms executable by processing circuitry, by a firmware implementation, a hardware implementation or a combination thereof. When implemented at a motor vehicle, the apparatus, and the exemplary implementation, includes portions positioned at the passenger compartment of the vehicle and includes control lines, here represented by the line  18 , that extend to a wiper motor  22 . The wiper motor is positionable in proximity to the wiper blade  12  to impart moving forces thereto. The wiper motor here forms an electric motor. In another implementation, the wiper motor forms a pneumatic motor or acutator.  
         [0028]     The apparatus includes a user interface, here having a first momentary contact switch  22  and a second momentary contact switch  24 . The switches  22  and  24  are positioned to permit their convenient actuation by a user, e.g., the operator of the vehicle at which the apparatus is positioned. The contact switches are positioned, for instance, at the steering column or steering wheel of the vehicle or are otherwise positioned in the passenger compartment of the vehicle.  
         [0029]     The contact switches are connected to a timer  26  and to a wiper blade movement controller  28 . When the contact switch  22  is actuated by a user, the indication of the actuation is provided to the timer  26  and also to the wiper blade movement controller  28 . And, similarly, when the contact switch  24  is actuated, an indication of the actuation is provided both to the timer  26  and to the wiper blade movement controller  28 . The timer and the controller are also connected, here represented by way of the line  32 . In one implementation, the functions performed by the timer and the wiper blade movement controller are carried out by algorithms executable at common processor circuitry, and the line  32  is representative of exchange of information between the respective algorithms during, or as a result of, their execution. The control lines  18  extend between the controller and the wiper motor. Control signals generated by the movement controller control operation of the wiper motor, that is to say, control signals generated by the controller cause actuation of the wiper motor to generate the moving forces that cause movement of the wiper blade.  
         [0030]     When an indication of the actuation of the contact switch  22  is provided to the timer, the timer commences timing a time-out value and also records, or times, a time period commencing with the actuation of the contact switch. If the second actuation of the contact switch is made before the expiration of the timer&#39;s time-out period, the time period between the two successive actuations of the contact switch is provided, by way of the line  32 , to the movement controller  28 . The time period separating the successive actuations of the contact switch  22 , if performed within the time-out period of the timer, that is, prior to expiration of the timer time-out, sets the repetition rate of the intermittent operation of the wiper blade caused by the movement controller  28 . If, conversely, the contact switch  22  is not actuated a second time within the time-out period of the timer, the controller does not set intermittent operation of the wiper blade. The time-out period of the timer is any desired time period, such as, e.g., a time period corresponding to the time period separating wiper blade motions during fixed, normal low-speed operation of the windshield wiper system.  
         [0031]     The direct connection between the contact switch  22  and the movement controller  28  also provides the movement controller with an indication each time in which the contact switch is actuated. In the exemplary implementation, the movement controller, upon reception of indication of the actuation of the contact switch, generates a control signal that causes the wiper motor to generate moving forces to cause wiping motion of the wiper blade. And, when the user actuates the contact switch two times within the time-out period of the timer, the first two repetitions of the wiper blade are caused directly as a result of the actuation of the contact switch. Thereafter, subsequent repetitions of the movement of the wiper blade are caused by control signals generated by the movement controller free of additional actuations of the contact switch.  
         [0032]     As the movement controller causes generation of the control signal to cause motion of the wiper blade responsive to actuation of the contact switch  22 , the wiper blade is caused to perform the wiping motion even when a second actuation of the contact switch occurs subsequent to the timing out of the timer  26 . The second actuation of the contact switch, occurring beyond the time-out period of the timer, is treated by the timer as a new, first actuation of the contact switch for purposes of setting automatic, intermittent operation of the wiper blade.  
         [0033]     The second contact switch  24  is actuated by the user to terminate the intermittent operation in which the wiper blade is intermittently caused to perform the wiping movement at the selected repetition rate. Upon detection of the actuation of the second contact switch  24 , the movement controller prevents further operation of the wiper motor to cause the wiper blade to perform another wiping motion. If the indication is detected in mid-motion of the wiper blade, the wiping motion of the wiping blade is completed.  
         [0034]     Thereby, a simple user interface permits a user, such as a driver of a vehicle to set the intermittent operation of the windshield wiper system and, subsequently, turned-off The repetition rate is selected merely through actuation of a single, momentary contact switch requiring minimal action on the part of the user and little distraction to the user when concentrating on other activities, such as operating the motor vehicle.  
         [0035]     The apparatus  10  here further includes a standard speed selector  36 , operable in conventional manner, to permit operation of the windshield wiper system in conventional manner, that is to say, to set the wiper motor at a fixed, low-speed or high-speed rate of operation. In one implementation, if the user sets the wiper blade motion using the standard speed selector  36 , intermittent operation is overridden with the selected standard speed.  
         [0036]      FIG. 2  illustrates a state diagram, shown generally at  42 , representative of operation of an embodiment of the present invention. The state diagram forms a state representation having four states, states  44 ,  46 ,  48 , and  52 . Implementation of the state representation in physical structure is straightforward either as a hardware device or by way of algorithms executable by processing circuitry.  
         [0037]     The first state  44  represents a starting state and the state to which operations return upon inactivity of the apparatus. At the first state, the timer is disabled, indicated by “disable TBW timer” in the figure. And, variables, TBW actual and TBW predicted are set to be, respectively, MAX_TBW_TIME and TBW actual.  
         [0038]     Entry into the second state  46  from the first state  44 , indicated by way of the path  54 , occurs when a manual wipe request is detected. With reference to the implementation shown in  FIG. 1 , the manual wipe request is made by a user through actuation of the first contact switch  22 . In the exemplary implementation, upon detection of the wipe request, the wiper blade is caused to perform a wiping motion across the windshield, or other, surface. In the event that subsequent to detection of the first manual wipe request, when in the second state  46 , no further wipe request is detected within the timing out period of the timer, a return is made, indicated by the TBW lapsed segment  56 , to the first state  44 .  
         [0039]     If, however, while in the second state, a manual wipe request is detected, a path  58  is taken to the third state  48 . And, when entering the third state, values of parameters are set. A TBW actual value is set to get TBW timer value, a TBW predicted value is set to TBW actual, and the TBW timer is set to a TBW predicted value.  
         [0040]     In the third state, if no other switches are actuated, the wiper time is thereby set to the time between requests, and the wiper blade shall subsequently automatically perform the wiping motions at the corresponding time intervals. The path  62  is representative of the wiping motion carried out by the wiper blade at the successive intervals. And, variables are set as indicated. A TBW actual value is set to get TBW timer value. A TBW predicted value is set to a TBW actual value, and a TBW timer value is set to the TBW predicted value.  
         [0041]     If, while in the third state  48 , an additional wipe request is detected, a path  64  is taken. Time elapsing between a prior movement of the wiper blade and the additional manual wipe request is loaded as a new time period to be used to define the repetition rate at which the wiper blade is to carry out its wiping motion. This additional manual wipe request is, in essence, interpreted to form a new user selection of the repetition rate. Parameters are again set in this path. The TBW actual value is set to a get TBW timer value, and TBW predicted value is set to a TBW actual value, and the TBW timer is set to the TBW predicted value.  
         [0042]     If, while in the third state  48 , a stop, i.e., terminate intermittent operation request is detected, the path  68  is taken to the fourth state  52 . The fourth state forms a wait state. Two paths extend from the wait state, a path  72  that extends back to the third state, and a path  74  that extends back to the first state  44 . When entering the fourth state  52 , the TBW timer is set to a maximum time between wiper blade motions, and upon timing out of the timer, the path  74  is taken back to the first state  44 . However, while in the fourth state  52 , if an additional wipe request is detected, the path  72  is taken back to the third state  48 . Thereby, upon detection of actuation of the stop request, a delay period expires before returning to the initial or inactive state  44 .  
         [0043]      FIG. 3  illustrates a process  82  of operation of an embodiment of the present invention. The process starts at the start block  84 . First, and as indicated by the decision block  86 , a determination is made as to whether a first switch is actuated. If not, the no branch is taken back to the decision block. If, however, the first switch is actuated, the yes branch is taken and timing commences, indicated by blocks  88  and  92 . The block  88  is representative of commencement of a timing period, and the block  92  is representative of commencement of a time-out period.  
         [0044]     A path is then taken to the decision block  94  at which a determination is made whether the time-out timer has timed out. If so, the yes branch is taken to the block  96 , and the timers are re-set. Then a branch is taken back to the block  86 .  
         [0045]     If, conversely, the time-out timer has not timed out, the no branch is taken to the decision block  102  at which a determination is made as to whether the first switch has been reactuated. If not, the no branch is taken back to the decision block  94 . Otherwise, if the first switch has been reactuated, the yes branch is taken to the block  104 . And, the repetition rate, corresponding to the time period commencing with the start of the timing at the block  88  and the detection of the reactuation of the first switch, of the wiper blade is set.  
         [0046]      FIG. 4  illustrates a method flow diagram, shown generally at  112 , representative of the method of operation of an embodiment of the present invention. The method controls intermittent movement of a wiper blade of a wiper.  
         [0047]     First, and as indicated by the block  114 , a first actuator is actuated. Then, and as indicated by the block  116 , the first actuator is re-actuated.  
         [0048]     A determination is made, indicated by the block  118 , of a time period separating the actuation of the first actuator and its re-actuation. Then, and as indicated by the block  122 , intermittent movement of the wiper blade is selected at a rate responsive to the determined time period.  
         [0049]     Then, and as indicated by the block  124 , a second actuator is actuated to terminate the intermittent movement of the wiper blade.  
         [0050]     Thereby, merely through successive actuation of a first actuator, the repetition rate of a wiper blade is set, permitting its intermittent operation. And, actuation of a second actuator terminates the intermittent operation of the wiper blade when no longer needed.  
         [0051]     The previous descriptions are of preferred examples for implementing the invention, and the scope of the invention should not necessarily be limited by this description. The scope of the present invention is defined by the following claims.