Patent Publication Number: US-7908061-B2

Title: Opening/closing member control apparatus and method

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based on and incorporates herein by reference Japanese Patent Application No. 2005-253102 filed on Sep. 1, 2005. 
     FIELD OF THE INVENTION 
     The present invention relates to an opening/closing member control apparatus and its controlling method, and, particularly to the opening/closing member control apparatus that controls a speed of an opening/closing member according to an opening/closing position thereof, and to its controlling method. 
     BACKGROUND OF THE INVENTION 
     Conventionally, a device for raising/lowering a windowpane of a vehicle is constructed, such that the windowpane is raised or lowered through an elevating mechanism by transmitting rotary driving force by an electric motor to the elevating mechanism. In such a raising/lowering device, a driving voltage is simply applied to the electric motor according to rising or descending of the windowpane. Thus, when the windowpane is lowered to a bottom lock position, the windowpane is mechanically constrained by a stopper, thereby applying excessive impact force to a drive system. Accordingly, there is a problem of an occurrence of an offensive impulsive sound, as well as deterioration in durability of the drive system. 
     In order to avoid making an impact, which results in serious deterioration in the durability of the drive system, it is proposed to stop rotation of the electric motor by stopping a drive of the electric motor immediately before the bottom lock position and by lowering the windowpane to the bottom lock position through inertia (e.g., JP2577092 Y2 (pp. 3-6, FIGS. 11, 12)). However, since such an art still employs a configuration to stop the windowpane at the bottom lock position, an operation stop noise is inevitably made when the windowpane stops. In addition, when an operation of the motor is stopped before the bottom lock position, a stop position of the windowpane varies, thereby stopping the windowpane above a belt molding, under an influence of a variation in a load because of deterioration due to age and the like. 
     SUMMARY OF THE INVENTION 
     The present invention aims for provision of an opening/closing member control apparatus that can stop an opening/closing member before a fully open position without making an impulsive sound while driving the opening/closing member in a direction toward the fully open position, and that can reduce a variation in its stop position, and for the provision of its controlling method. 
     According to one aspect of the present invention, the opening/closing member control apparatus includes the opening/closing member, a drive mechanism, a position detector, and a control device. The opening/closing member can move between the fully open position and a fully closed position. The drive mechanism drives the opening/closing member to be opened or closed via the drive mechanism by operating a motor. The position detector detects a position of the opening/closing member. The control device controls drive of the motor based on a detected position of the opening/closing member. The control device stores a first set position that is set between the fully open and closed positions, and a second set position that is set between the fully open position and the first set position, as well as adjacently to the fully open position. While driving the opening/closing member in the direction toward the fully open position, the control device reduces a motor output after the opening/closing member reaches the first set position until it reaches the second set position. The control device de-energizes the motor when the opening/closing member reaches the second set position. The second set position is set at a position, from which the opening/closing member cannot reach the fully open position with its movement speed at the time the motor is de-energized. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a power window device according to an embodiment of the present invention; 
         FIG. 2  is a block diagram of the power window device in  FIG. 1 ; 
         FIG. 3  is a diagram showing a relationship between a windowpane position and a motor output; 
         FIG. 4  is a diagram showing a relationship between a windowpane position and a motor application voltage; 
         FIG. 5  is a flowchart showing setting processing of a controller; 
         FIG. 6  is a flowchart showing an operation of a controller to fully open a windowpane; 
         FIGS. 7A ,  7 B are diagrams showing relationships of a windowpane position to a motor output and to a motor rotation speed, respectively, according to a comparative example; 
         FIGS. 8A ,  8 B are diagrams showing relationships of a windowpane position to a motor output and to a motor rotation speed, respectively, according to the present embodiment; 
         FIGS. 9A ,  9 B are diagrams, each of which shows a relationship between a windowpane position and a motor output according to a modification; and 
         FIGS. 10A ,  10 B are diagrams, each of which shows a relationship between a windowpane position and a motor output according to a modification. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT 
     With reference to  FIG. 1 , a power window device  1  is provided to move up and down (closes and opens) a windowpane  11  as an opening/closing member arranged in a door  10  of a vehicle by a rotary drive of a motor  20 . A drive mechanism  2  that opens and closes the windowpane  11 , a control device  3  to control an operation of the drive mechanism  2 , and an operating switch  4  for an occupant to command the operation are main components of the device  1 . 
     The windowpane  11  moves up and down along a rail (not shown) between an upper fully closed position (top) D and a lower fully open position (bottom) A. 
     The motor  20  having a speed reducing mechanism secured to the door  10 , an elevating arm  21  with a fan-shaped gear  21   a  driven by the motor  20 , a driven arm  22  that is pivoted to cross the elevating arm  21 , a fixed channel  23  fixed to the door  10 , and a glass-side channel  24  integrated with the windowpane  11  are main components of the drive mechanism  2 . 
     The motor  20  is configured such that a rotor rotates forward and reverse as a result of a magnetic attraction effect generated between the rotor and a stator having a magnet by energizing a winding of the rotor after receiving an electric power supply from the control device  3 . In the drive mechanism  2 , when the elevating and driven arms  21 ,  22  swing correspondingly to rotation of the motor  20 , sliding of their ends is restricted by the channels  24 ,  23 , respectively, and the elevating and driven arms  21 ,  22  are driven as an X-link, thereby moving up and down the windowpane  11 . 
     The motor  20  is integrated with a rotation detector  27 . The rotation detector  27  outputs a pulse signal (rotation speed signal), which is synchronized with the rotation of the motor  20 , to the control device  3 . The rotation detector  27  is configured to detect a magnetic variation of the magnet that rotates with an output shaft of the motor  20  by means of a plurality of Hall elements. That is, the pulse signal is outputted according to each predetermined movement of the windowpane  11  or each predetermined rotation angle of the motor  20 . Accordingly, the rotation detector  27  can output a signal that corresponds to a movement of the windowpane  11 , which is approximately proportional to a rotation speed of the motor  20 . Then, the control device  3  detects a position of the windowpane  11  by the pulse signal from the rotation detector  27 . The position is detected by the rotation detector  27  and the control device  3 . 
     In addition, while the Hall elements are employed for the rotation detector  27 , an encoder may be employed as long as it can detect the rotation of the motor  20 . Also, although the motor  20  is integrated with the rotation detector  27  to detect a rotation of the output shaft of the motor  20 , the position of the windowpane  11  may be directly detected by other known detectors. 
     The control device  3  includes a controller  31  and a driver circuit  32 . The controller  31  and the driver circuit  32  are fed with electric power, which is necessary for their operations, by a battery  5  mounted in the vehicle. The controller  31  includes a microcomputer that has a CPU, memories such as a ROM and a RAM, an input circuit, an output circuit, and the like. The CPU is connected to the memories, the input circuit, and the output circuit via a bus. Additionally, without being limited to this, the controller  31  may include a DSP or a gate array. 
     The controller  31  normally rotates the motor  20  forward and reverse through the driver circuit  32  based on an operating signal from the operating switch  4 , thereby opening and closing the windowpane  11 . Also, the controller  31  detects the position of the windowpane  11  based on the pulse signal received from the rotation detector  27 , and regulates a magnitude of driving power, which is supplied to the motor  20  through the driver circuit  32  according to a detected position of the windowpane  11 . More specifically, a magnitude of a drive voltage, or that of a duty ratio if the driving power is PWM-controlled, is regulated. By this means, a motor output is regulated. 
     The driver circuit  32  includes an IC that has an FET, and reverses polarity of the electric power supply to the motor  20  based on an input signal from the controller  31 . That is, the driver circuit  32  feeds the electric power to the motor  20  in order to rotate the motor  20  in a forward rotating direction when the driver circuit  32  receives a forward rotation command signal from the controller  31 . It feeds the electric power to the motor  20  in order to rotate the motor  20  in a reverse rotating direction when the driver circuit  32  receives a reverse rotation command signal from the controller  31 . In addition, the driver circuit  32  may be configured to reverse the polarity using a relay circuit. As well, the driver circuit  32  may be configured to be incorporated into the controller  31 . 
     The controller  31  detects a rising or descending part (a pulse edge) of the pulse signal that is inputted, and detects a rotating direction of the motor  20  based on a phase difference between each pulse signal. It also calculates the rotation speed (rotational period) of the motor  20  based on an interval (period) between the pulse edges. In other words, the controller  31  indirectly calculates the movement speed of the windowpane  11  based on the rotation speed (rotational period) of the motor  20 , and identifies a moving direction of the windowpane  11  based on the rotating direction of the motor  20 . Besides, the controller  31  counts the pulse edges. This pulse count value is added or subtracted according to an opening or closing movement of the windowpane  11 . The controller  31  identifies an opening or closing position of the windowpane  11  by a magnitude of the pulse count value. 
     That is, the fully open position A is designated as a reference position, and the pulse count value is set at 0 (zero) at the fully open position A. One increment (+1) is added to the pulse count value every time the pulse signal is received while the windowpane  11  is moving up toward the fully closed position D, whereas one decrement (−1) is subtracted from the pulse count value every time the pulse signal is received while the windowpane  11  is moving down toward the fully open position A. 
     The operating switch  4  includes a swing type switch or the like, which allows a two-step operation, and has an opening switch, a closing switch and an automatic switch. By the occupant operating this operating switch  4 , a command signal to open or close the windowpane  11  is outputted to the controller  31 . 
     More specifically, when the operating switch  4  is operated toward its one end side by one step, the opening switch is turned on, and the operating switch  4  outputs to the controller  31  a normal opening command signal to perform a normal opening operation (i.e., an opening operation only while operated) on the windowpane  11 . Also, when the operating switch  4  is operated toward the other end side by one step, the closing switch is turned on, and the operating switch  4  outputs to the controller  31  a normal closing command signal to perform a normal closing operation (i.e., a closing operation only while operated) on the windowpane  11 . 
     In addition, when the operating switch  4  is operated toward its one end side by two steps, both the opening switch and the automatic switch are turned on, and the operating switch  4  outputs to the controller  31  an automatic opening command signal to perform an automatic opening operation (i.e., the opening operation to the fully open position even after the operation is stopped) on the windowpane  11 . Also, when the operating switch  4  is operated toward the other end side by two steps, both the closing switch and the automatic switch are turned on, and the operating switch  4  outputs to the controller  31  an automatic closing command signal to perform an automatic closing operation (i.e., the closing operation to the fully closed position even after the operation is stopped) on the windowpane  11 . 
     The controller  31  performs the normal opening operation on the windowpane  11  by driving the motor  20  through the driver circuit  32  all the while that the controller  31  is receiving the normal opening command signal from the operating switch  4  (all the while that the operating switch  4  is being operated). On the other hand, the controller  31  performs the normal closing operation on the windowpane  11  by driving the motor  20  through the driver circuit  32  all the while that the controller  31  is receiving the normal closing command signal from the operating switch  4  (all the while that the operating switch  4  is being operated). 
     Furthermore, when the controller  31  receives the automatic opening command signal from the operating switch  4 , the controller  31  performs the automatic opening operation on the windowpane  11  to the fully open position by driving the motor  20  through the driver circuit  32 . On the other hand, when the controller  31  receives the automatic closing command signal from the operating switch  4 , the controller  31  performs the automatic closing operation on the windowpane  11  to the fully closed position by driving the motor  20  through the driver circuit  32 . 
     In the above configuration, the controller  31  stores the pulse count values at the fully open position (bottom lock position) A and at the fully closed position (top) D in the memory, and as described above, identifies the position of the windowpane  11  by the pulse count values to be added or subtracted according to rising or descending of the windowpane  11 . Besides, between the fully open position A and the fully closed position D, a speed control start position C as a first set position is set at a predetermined position adjacent to the fully open position A as shown in  FIGS. 1 ,  3 . Then, between the speed control start position C and the fully open position A, a speed control end position B is set adjacently to the fully open position A. 
     When the controller  31  receives the continuous normal or automatic opening command signal from the operating switch  4 , the controller  31  continuously feeds the driving voltage to drive the motor  20  in a direction toward the fully open position A. Accordingly, the motor  20  provides the drive mechanism with a motor output shown in  FIG. 3  to drive the windowpane  11 . 
     That is, from the fully closed position D to the speed control start position C, the controller  31  supplies the motor  20  with the driving voltage to provide a generally constant high motor output. Following this, when the windowpane  11  reaches the speed control start position C, the controller  31  starts control to reduce the motor output. 
     Additionally, although the controller  31  is configured to provide the generally constant high motor output from the fully closed position D to the speed control start position C, it may be configured to increase the motor output from a low motor output gradually to a high motor output to gently start the motor  20 , after providing a high motor output over a short period of time during an initial phase of operation. 
     The controller  31  controls the motor  20  in such a manner that the motor output is gradually reduced from the speed control start position C to the speed control end position B. The motor output is reduced in proportion to a movement distance so that the motor output takes the value of 0 (zero) at the speed control end position B. A descending speed of the windowpane  11  becomes slower as the motor output is reduced in this manner. 
     The motor  20  is de-energized at the speed control end position B, and thus the motor output takes the value of 0 (zero). Even after the driving power supplied to the motor  20  is cut off, the windowpane  11  slightly moves down in the direction toward the fully open position A due to its own weight and inertia force that results from its movement. Meanwhile, drag force and sliding resistance, which are generated from the drive mechanism and the motor  20 , hinder the windowpane  11  descending, thereby reducing its movement speed. Consequently, a top end of the windowpane  11  moves beyond a belt molding and stops moving down at a predetermined position before the fully open position A. 
     The speed control end position B is set at a position, from which the windowpane  11  cannot reach the fully open position A with its movement speed at the time the motor  20  is de-energized. That is, from the speed control start position C to the speed control end position B, the movement speed of the windowpane  11  is reduced, and then the windowpane  11  moves from the speed control end position B toward the fully open position A by means of its own weight and the inertia force that is caused by the reduced movement speed. More specifically, the speed control end position B and the movement speed of the windowpane  11  at this position are set, such that the windowpane  11  does not reach the fully open position A and stops moving down at the predetermined position before the fully open position A with its movement speed at the speed control end position B. 
     Besides, because the motor  20  is de-energized with its movement speed being reduced, the windowpane  11  can be stopped with hardly any deviations from a predetermined stop position. Therefore, even if the sliding resistance and the like caused by deterioration due to age vary, it can be ensured that the top end of the windowpane  11  moves down beyond the belt molding and that the windowpane  11  is stopped before the fully open position A. 
     In this manner, since the windowpane  11  is configured such that its top end moves down beyond the belt molding and that it stops within a narrow range before the fully open position A, an occurrence of an impulsive sound, which is made by the drive mechanism and the windowpane  11  coming into contact with a stopper and the like when the windowpane  11  is stopped, can be restricted. For this reason, an incidence of slight damage, which is cumulatively caused to the drive mechanism and the like every time the windowpane  11  is stopped, can be restricted, thereby continuously ensuring durability of the drive mechanism. 
     Similar to  FIG. 3 ,  FIG. 4  illustrates a state where the windowpane  11  is being fully opened. Its vertical axis corresponds to a motor application voltage, and its horizontal axis corresponds to the position of the windowpane  11 . 
     The controller  31  drives the motor  20  at a voltage (battery voltage) V 1  from the fully closed position D to the speed control start position C, and controls the motor  20  to gradually reduce the drive voltage (applied voltage) from the speed control start position C to the speed control end position B. The applied voltage is reduced in proportion to the movement distance so that it is reduced to V 2  at the speed control end position B. 
     The voltage V 2  is a voltage, at which the motor  20  cannot drive the drive mechanism even if it is applied to the motor  20 . Accordingly, the motor output comes to be 0 (zero) even if the voltage V 2  is applied to the motor  20 . Then, the motor  20  is de-energized at the speed control end position B, so that the motor application voltage is reduced to 0 (zero). 
     In addition, the controller  31  may be configured to apply a voltage that is equal to or lower than V 2  to the motor  20  for a predetermined time to assist the windowpane  11  in descending without de-energizing the motor  20  at the speed control end position B. 
     As well, if the controller  31  PWM-controls the motor  20  without reducing the voltage applied to the motor  20 , the duty ratio may be reduced. For example, the motor  20  may be controlled, such that the duty ratio is set at 100% from the fully closed position D to the speed control start position C, and that the duty ratio is gradually reduced from the speed control start position C to the speed control end position B. 
     Next, an operation of the controller  31  will be described based on  FIGS. 5 ,  6 . 
     First, in setting processing in  FIG. 5 , the windowpane  11  having been moved to the fully open position (bottom position) A, the number of pulse counts stored in the controller  31  is reset to zero at step S 1 . Subsequently, at step S 2 , with the fully open position A designated as the reference position, the windowpane  11  is moved up to the speed control end position B, the pulse count value at which is stored in the controller  31 . 
     Second, at step S 3 , the windowpane  11  is moved up to the speed control start position C with the fully open position A being the reference position, and the pulse count value at the speed control start position C is stored in the controller  31 . 
     After the pulse count values at the speed control end position B and the speed control start position C are set by this means, a variation in the applied voltage to the motor  20  from the speed control start position C to the speed control end position B is read into the controller  31  and is set at step S 4 . 
     In the device  1 , the speed control end position B and the speed control start position C can be set by designating the fully open position A as their reference position, thereby making easier appropriate setting of a stop position of the windowpane  11  before the fully open position A regardless of vehicles or their types. 
     Next, based on  FIG. 6 , speed control processing by the controller  31  in lowering the windowpane  11  toward the fully open position A will be described. This processing is repeatedly performed at intervals of a predetermined time. The drive voltage applied to the motor  20  is regulated according to the position of the windowpane  11  in this processing. 
     The controller  31  monitors whether the normal or automatic opening command signal is received from the operating switch  4  so as to lower and open the windowpane  11  (step S 11 ). If the normal or automatic opening command signal is not received from the operating switch  4  (step S 11 : NO), the processing is ended for the meantime, and this processing is repeated again after a predetermined time. 
     On the other hand, if the normal or automatic opening command signal is received from the operating switch  4  (step S 11 : YES), the controller  31  determines whether the present position of the windowpane  11  reaches the speed control start position C (step S 12 ). That is, whether the present position of the windowpane  11  is located between the speed control start position C and the fully open position A is determined. 
     If the present position of the windowpane  11  does not reach the speed control start position C (step S 12 : NO), the processing is ended for the meantime. That is, in this state, the windowpane  11  is located between the fully closed position D and the speed control start position C. Since the controller  31  does not control a speed to gently stop the windowpane  11  in this interval, the applied voltage to the motor  20  is set at V 1  (battery voltage). Hence, the windowpane  11  moves down with a normal movement speed. 
     Meanwhile, if the present position of the windowpane  11  reaches the speed control start position C (step S 12 : YES), the controller  31  determines whether the present position of the windowpane  11  reaches the speed control end position B (step S 13 ). That is, whether the present position of the windowpane  11  is located between the speed control end position B and the fully open position A is determined. 
     If the present position of the windowpane  11  does not reach the speed control end position B (step S 13 : NO), the controller  31  regulates the drive voltage applied to the motor  20  according to the present position of the windowpane  11  at step S 14 , and then ends the processing. That is, in this state, the windowpane  11  is located between the speed control start position C and the speed control end position B, and in this interval, the controller  31  reads out the motor application voltage, which is set according to the position of the windowpane  11 , to control a motor speed by applying the voltage set as shown in  FIG. 4  to the motor  20 . 
     This speed control processing (step S 14 ) is performed until the windowpane  11  reaches the speed control end position B. As a consequence, the rotation speed of the motor  20  is reduced, thereby reducing the descending speed of the windowpane  11 . The applied voltage to the motor  20  is gradually reduced so that it takes the value of V 2  at the speed control end position B. 
     On the other hand, if the present position of the windowpane  11  reaches the speed control end position B (step S 13 : YES), the motor  20  is de-energized, and the processing is ended. After the de-energization of the motor  20 , the windowpane  11  continues moving down toward the fully open position A by its own weight and the inertia force that results from its movement as above, and stops at the predetermined position before the fully open position A. 
     In this manner, between the speed control start position C and the speed control end position B, the drive voltage applied to the motor  20  is regulated to gently stop the windowpane  11  according to the position of the windowpane  11 . Subsequently, from the speed control end position B adjacent to the fully open position A, the windowpane  11  makes a slight movement down toward the fully open position A by its own weight and the inertia force of its movement speed, and stops at the predetermined position. 
     Next, a fully opening operation of the windowpane, the speed of which is controlled by the device  1  of this case, will be compared to a comparative example, in which the speed is not controlled. 
     In the case where the speed control is not carried out, as shown in  FIG. 7A , the motor is de-energized at an output stop position E, which is adjacent to the fully open position A, and the motor output comes to be 0 (zero). Consequently, as shown in  FIG. 7B , if the sliding resistance is small (load: small), the motor rotation speed is reduced to 0 (zero) when the windowpane moves down past the output stop position E and reaches the fully open position A. That is, operations of the windowpane and the drive mechanism are forcibly stopped at the fully open position A due to their contact with the stopper and the like. Accordingly, a stopping sound is generated, and a relatively small impact is applied to the drive mechanism. If the sliding resistance is large (load: large) because of the deterioration due to age and the like, the motor rotation speed rapidly becomes small after the windowpane moves down past the output stop position E because of the large load, and comes to be 0 (zero) before the windowpane reaches the fully open position A. 
     As above, since the movement speed of the windowpane is high at an instant the motor is de-energized, the movement distance from the output stop position E differs significantly in proportion to a magnitude of the sliding resistance. Therefore, a variation in a stop position of the windowpane becomes considerable. 
     Meanwhile, in the device  1  of the present example, because the motor output is reduced from the speed control start position C to the speed control end position B as shown in  FIG. 8A , the movement speed of the windowpane  11  is made slow at the speed control end position B. In consequence, the windowpane  11  moves down only by a small movement distance from the speed control end position B. 
     Thus, the movement distance from the speed control end position B does not differ considerably between the small sliding resistance applied to the windowpane  11  (load: small) and the great sliding resistance (load: large). Consequently, a major variation in the stop position of the windowpane  11 , which depends upon the magnitude of the sliding resistance, is not caused. In this manner, in the device  1  of the present example, the variation in the stop position of the windowpane  11  due to a variation in the sliding resistance, which stems from the deterioration due to age and the like, can be reduced. 
     In the above embodiment, the motor output may be reduced as shown in  FIGS. 9A ,  9 B, and  FIGS. 10A ,  10 B, in addition to the linear reduction in the motor output in proportion to the movement speed of the windowpane  11  from the speed control start position C to the speed control end position B as shown in  FIG. 3 . 
       FIG. 9A  shows an example, in which the motor output is reduced stepwise from the speed control start position C to the speed control end position B. In the meantime, the applied voltage to the motor  20  is reduced stepwise as well.  FIG. 9B  shows an example, in which the motor output is exponentially reduced from the speed control start position C to the speed control end position B. In this example, a reduction rate of the motor output is set at a larger value as the windowpane  11  is located closer to the speed control start position C than the speed control end position B. 
       FIG. 10A  shows an example, in which the motor output is linearly reduced from the speed control start position C to the speed control end position B. The motor output is reduced to have a predetermined value instead of 0 (zero) in a phase where the windowpane  11  is yet to reach the speed control end position B. Then, in a phase where the windowpane  11  has reached the speed control end position B, the motor output is controlled to be reduced to 0 (zero). Thus, in this example, the movement speed of the windowpane  11  at the speed control end position B is set at a large value.  FIG. 10B  shows an example, in which the motor output is reduced in a sweeping manner from the speed control start position C to the speed control end position B. In this example, the reduction rate of the motor output is set at a larger value as the windowpane  11  is located closer to the speed control end position B than the speed control start position C. 
     By virtue of various settings at which the motor output varies as in the above modifications, the movement speed and acceleration of the windowpane  11  at the speed control end position B can be regulated. 
     Besides, the above embodiments are applications of the opening/closing member control apparatus to the power window device  1  of the vehicle. Nevertheless, the opening/closing member control apparatus may be applied to an apparatus that opens or closes an opening/closing member, such as a sunroof opening/closing apparatus and a sliding door opening/closing apparatus.