Abstract:
A wiper system for a vehicle includes a first wiper assembly, a second wiper assembly spaced apart from the first wiper assembly, and a controller in communication with at least one of the first wiper assembly and the second wiper assembly. The controller controls at least one of the first wiper assembly and the second wiper assembly based on at least one of an aerodynamic characteristic of the vehicle and a soiling characteristic of the vehicle.

Description:
FIELD 
     The present disclosure relates to vehicle windshield wipers, and more particularly, to a control algorithm for a front and rear wiper system. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Many modern vehicles, particularly sport utility and cross-over vehicles, are equipped with wiper systems for both a front windshield and a rear windshield. Typically, the front and rear wiper systems are independently controlled and operated and therefore require separate control interfaces and related hardware. The separate control interfaces and hardware increase the overall cost and complexity of each system, as operators are required to monitor and adjust each system separately. 
     SUMMARY 
     A wiper system for a vehicle includes a first wiper assembly, a second wiper assembly spaced apart from the first wiper assembly, and a controller in communication with at least one of the first wiper assembly and the second wiper assembly. The controller controls at least one of the first wiper assembly and the second wiper assembly based on at least one of an aerodynamic characteristic of the vehicle and a soiling characteristic of the vehicle. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1  is a schematic view of a vehicle including a wiper system according to the principles of the present invention; 
         FIG. 2  is a perspective view of a user interface for use with the wiper system of  FIG. 1 ; 
         FIG. 3  is a schematic view of a wiper system according to the principles of the present invention; and 
         FIG. 4  is a schematic view of a wiper system according to the principles of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     With reference to  FIG. 1 , a wiper system  10  is provided and includes a front-wiper assembly  12 , a rear-wiper assembly  14 , and a controller  16 . The wiper system  10  may be installed in a vehicle  18  to clear precipitation and debris from a front windshield  20  and a rear windshield  22  of the vehicle  18 . 
     The front-wiper assembly  12  may include a user interface  24  to allow a user to control the front-wiper assembly  12 . The user interface  24  may be disposed on a stalk  26  protruding from a steering column  28  of the vehicle  18 , may include a plurality of selectable positions  30 , and may be in electrical communication with the controller  16 . 
     The selectable positions  30  communicate with the controller  16  to allow the controller to drive a pair of front wipers  13  of the front-wiper assembly  12  at a desired speed and/or frequency. While the user interface  24  is described and shown as being disposed on a stalk  26  of the vehicle  18 , the user interface  24  could alternatively be located at any location within the vehicle  18  such as, for example, on an instrument panel (not shown). 
     The rear-wiper assembly  14  is in electrical communication with the controller  16  to allow the controller  16  to selectively control a rear wiper  15  of the rear-wiper assembly  14 . The controller  16  calculates an appropriate operating speed and/or frequency of the rear-wiper assembly  14  based on any or all of the following parameters: the selected position  30  of the user interface  24 , the operating speed and/or frequency of the front-wiper assembly  12 , the aerodynamic characteristics of the vehicle  18 , the soiling characteristics of the vehicle  18 , and the velocity of the vehicle  18 . 
     With reference to  FIG. 3 , operation of the wiper system  10  will be described in detail. As described above, the user interface  24  is in communication with both the front-wiper assembly  12  and the controller  16 . When the user interface  24  is adjusted and a position  30  is selected, the front wipers  13  of the front-wiper assembly  12  are driven at a desired speed and/or frequency. In one configuration, the input to the user interface  24  is sent directly to the front-wiper assembly  12  to control operation of the front wipers  13 . In another configuration, input received by the user interface  24  is sent to the controller  16  to allow the controller  16  to control the front wipers  13  of the front-wiper assembly  12 . In either configuration, the front wipers  13  are driven at a desired speed and/or frequency based on the input received by the user interface  24 . 
     It should be noted that while the front wipers  13  may be directly controlled by the user interface  24 , that the input received by the user interface  24  is transmitted to the controller  16  to allow the controller  16  to control the rear-wiper assembly  14 , as will be described further below. 
     The controller  16  is in communication with the rear wiper  15  of the rear-wiper assembly  14  and controls the speed and/or frequency of the rear wiper  15  based on at least one of the input received by the user interface  24 , a velocity of the vehicle  18 , aerodynamic characteristics of the vehicle  18  and soiling characteristics of the vehicle  18 . 
     The controller  16  receives information from the user interface  24  as to the speed and/or frequency of the front wipers  13  of the front-wiper assembly  12 . The controller  16  may combine the information received from the user interface  24  with that of the velocity of the vehicle  18 , aerodynamic characteristics of the vehicle  18 , and soiling characteristics of the vehicle  18  to adjust the speed and/or frequency of the rear wiper  15  of the rear-wiper assembly  14 . 
     The velocity of the vehicle  18  may be received by the controller  16  from a body controller  36 . The body controller  36  may be in communication with a speed sensor  37 , which provides the body controller  36  with a signal indicative of the speed of the vehicle  18 . The aerodynamic characteristics of the vehicle  18  may be programmed into at least one of the controller  16  and/or the body controller  36  and provide the controller  16  and/or body controller  36  with information relating to the overall shape and profile of the vehicle. 
     If the body controller  36  contains information relating to the aerodynamic characteristics of the vehicle  18 , the controller  16  may communicate with the body controller  36  to retrieve the aerodynamic characteristics of the particular vehicle  18  from the body controller  36 . By storing the aerodynamic characteristics of the particular vehicle  18  in the body controller  36 , a generic controller  16  of the wiper system  10  may be used with various vehicles  18  without requiring the controller  16  to be programmed for each particular vehicle  18 . While the controller  16  may retrieve the aerodynamic characteristics of the particular vehicle  18  from the body controller  36 , the controller  16  could be programmed with the aerodynamic characteristics of the particular vehicle  18 . 
     The soiling characteristics of the vehicle  18  may be determined by testing the particular vehicle  18  via simulation, road testing, and/or laboratory testing. For example, the vehicle  18  may be driven through various environmental conditions such as wind, rain, and snow and over various road conditions such as uneven and unpaved road surfaces. The effects of the various combinations of environmental conditions and road conditions on the front and rear windshields  20 ,  22  may be observed as the vehicle  18  is tested. The observations as to the soiling of the front and rear windshields  20 ,  22  may be noted and programmed into the controller  16  and/or body controller  36 . 
     As with the aerodynamic characteristics of the vehicle  18 , the body controller  36  may only contain the aerodynamic characteristics of the particular vehicle  18  such that the controller  16  of the wiper system  10  must interrogate the body controller  36  to retrieve the soiling characteristics for the particular vehicle  18 . By only storing the soiling characteristics of the particular vehicle  18  in the body controller  36 , the controller  16  of the wiper system  10  may be used with any vehicle  18 . Alternatively, the soiling characteristics of the vehicle  18  may be stored within both the controller  16  and the body controller  36 . 
     In operation, the controller  16  analyzes the user input received from the user interface  24 , the velocity of the vehicle  18 , the aerodynamic characteristics of the vehicle  18 , and the soiling characteristics of the vehicle  18  to adjust the speed and/or frequency of the rear wiper  15 . 
     While the rear wiper  15  of the wear-wiper assembly  14  may be controlled by the controller  16 , as described above, the rear wiper  15  may alternatively be controlled by a manual override system  40 . For example, the rear-wiper assembly  14  may include a selection on the stalk  26  that allows a user to override the controller  16  and manually control the speed and/or frequency of the rear wiper  15 . The manual override system  40  may be employed when the vehicle  18  is driven through environmental conditions that subject the vehicle to extreme soiling such as, for example, off road and/or muddy conditions. Under such conditions, a user may override the controller  16  via the manual override system  40  to clean the rear windshield  22  by actuating the rear wiper  15  of the rear-wiper assembly  14 . 
     With reference to  FIG. 4 , a wiper system  10   a  is provided and includes a front-wiper assembly  12 , a rear-wiper assembly  14 , and a controller  16   a . In view of the substantial similarities in structure and function of the components associated with the wiper system  10  with respect to the wiper system  10   a , like reference numerals are used hereinafter and in the drawings to identify like components while like reference numerals containing letter extensions are used to identify those components that have been modified. 
     The controller  16   a  may control one or both of the front-wiper assembly  12  and rear-wiper assembly  14  based on a velocity of the vehicle  18 , aerodynamic characteristics of the vehicle  18 , and soiling characteristics of the vehicle  18 . In addition, the controller  16   a  may also control at least one of the front-wiper assembly  12  and rear-wiper assembly  14  based on information received from a precipitation sensor  52 . 
     The precipitation sensor  52  may be disposed proximate to or on one or both of the front windshield  20  and rear windshield  22  to provide the controller  16   a  with information regarding moisture on either or both of the front windshield  20  and rear windshield  22 . Based on the amount of moisture on either or both of the front windshield  20  and rear windshield  22 , the controller  16   a  may control one or both of the front-wiper assembly  12  and rear-wiper assembly  14 . 
     For example, if the precipitation sensor  52  indicates to the controller  16   a  that the front windshield  20  is being subjected to a heavy rainfall, the controller  16   a  may automatically instruct the front-wiper assembly  12  to actuate the front wipers  13  at a high speed and/or frequency. As with the wiper system  10 , the controller  16   a  may utilize the speed and/or frequency of the front wipers  13  in controlling the rear wiper  15  of the rear-wiper assembly  14  to control the rear wiper  15  at a high speed and/or frequency. If the precipitation sensor  52  indicates to the controller  16   a  that a minimal amount of moisture is disposed on the front windshield  20 , the controller  16   a  may drive the front wipers  13  of the front-wiper assembly  12  at a lower speed and/or frequency. The controller  16   a  may utilize the speed of the front wipers  13  in controlling the rear wiper  15  of the rear-wiper assembly  14  and similarly control the rear wiper  15  at a low speed and/or frequency. 
     In addition to utilizing information from the precipitation sensor  52 , the controller  16   a  may also use the velocity of the vehicle  18 , the aerodynamic characteristics of the vehicle  18 , and the soiling characteristics of the vehicle  18  in determining the speed and/or frequency of the front wipers  13  and rear wiper  15 . As such, the controller  16   a  can tailor the speed and/or frequency of the front wipers  13  and rear wiper  15  based on current environmental conditions (i.e., amount of rain, wind, ice, snow, etc.) as well as the speed of the vehicle  18 , aerodynamic characteristics of the vehicle  18 , and soiling characteristics of the vehicle  18 . 
     A manual override system  40  may be in communication with the front-wiper assembly  12  and/or rear-wiper assembly  14  to permit a user to override the controller  16   a  and directly control the front-wiper assembly  12  and rear-wiper assembly  14 . As with the wiper system  10 , the manual override system  40  may override the controller  16   a  when the vehicle  18  is driven in extreme environmental conditions (i.e., heavy rain, snow, ice, etc.) and/or over rough and/or muddy road surfaces. The manual override system  40  permits the user to actuate the front wipers  13  of the front-wiper assembly  12  and/or rear wiper  15  of the rear-wiper assembly  14  to clear the front windshield  20  and/or rear windshield  22  if either windshield  20 ,  22  is heavily soiled. The manual override system  40  may be actuated by depressing a button and/or switch located on the stalk  26  or instrument panel. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.