JP2008064239A - Control device for shift range selector mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect the abnormal condition of electric power supplied to an actuator while suppressing the complicated construction of a shift range selector mechanism and an increase in the cost. <P>SOLUTION: An SBW-ECU executes a program which includes a step (S104) of detecting voltage during wall abutting control (YES in S100) when there is a change in the time change rate of a counter value (YES in S102), a step (S106) of detecting a temperature, and a step (S110) of carrying out the processing of abnormality when an absolute value for the time change rate of the counter value is a function ΔCNT (V, TH) or greater (NO in S108). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to control of a shift switching mechanism of an automatic transmission, and more particularly to a technique for accurately detecting an abnormality in a circuit that limits power supplied to an actuator that switches a shift position while suppressing an increase in cost.

  2. Description of the Related Art Conventionally, in a shift position switching device that switches the shift position of an automatic transmission using an actuator in accordance with the operation of a shift lever by a driver, it is known to have an electric motor (for example, a DC motor) as a power source for shift position switching. Yes.

  According to such a shift position switching device, the shift lever and the shift position switching mechanism are mechanically connected like a general switching device that directly switches the shift position of the automatic transmission by the operating force of the shift lever by the driver. Since there is no need to connect, there is no restriction on the layout when these parts are mounted on a vehicle, and the degree of freedom in design can be increased. Further, there is an advantage that the assembling work to the vehicle can be easily performed.

  For example, Japanese Patent Laying-Open No. 2005-90575 (Patent Document 1) discloses a shift position switching device that reduces a load applied to a shift switching mechanism in switching a shift position. This shift position switching device is driven by an actuator, shift means for switching the shift position, restriction means for restricting rotation of the actuator in a predetermined direction at a predetermined shift position, and the amount of rotation of the actuator Counting means for obtaining the counted value, rotation control means for controlling the rotation of the actuator, and counting when the actuator is rotated by the rotation control means in a direction in which the rotation of the actuator is regulated by the regulating means. Based on the state of the count value acquired by the means, a position setting means for setting the reference position of the actuator corresponding to the predetermined shift position, and when the reference position is set, the reference means starts setting the reference position. Based on the count value acquired at the time and at the end of setting Reduction amount includes an instruction means for instructing the position setting means as in response to exceeding the predetermined change amount, again setting the reference position.

According to the shift position switching device disclosed in the above-mentioned publication, when a reference position corresponding to a predetermined shift position is set, the amount of change based on the count values respectively acquired by the counting means at the start of setting and at the end of setting If is larger, the reference position is reset. That is, when the P wall position is detected using the non-P position as the setting start position, the P wall position from the P position to the P wall can be detected again. The rotational force of the actuator when detecting the reference position from the P position to the P wall position is smaller than when detecting the reference position from the non-P position. Therefore, the detection of the P wall position from the P position has a low load on the restricting means. That is, by setting the reference position from a predetermined shift position, the deformation of the detent spring can be prevented or reduced. Since the deformation of the detent spring can be prevented or reduced, the durability of the shift switching mechanism is improved by correctly setting the reference position at a predetermined shift position. As a result, the load on the shift position switching mechanism can be reduced.
JP 2005-90575 A

  However, in the above publication, no consideration is given to the influence when an actuator with high output characteristics is selected.

  That is, when an actuator having a high output characteristic (especially output torque) is selected for the purpose of improving the response in the shift switching mechanism, a power limiting circuit for limiting the power supplied to the actuator may be required. . This is because, for example, when the actuator is actually operated and the movable range of the actuator is detected, the members constituting the shift switching mechanism may be deformed. Further, when such a power limiting circuit is provided, it is necessary to newly provide an abnormality detection circuit that determines whether or not the power limiting circuit is functioning normally. Therefore, there is a problem that the structure of the shift switching mechanism becomes complicated and the cost increases.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to prevent an abnormal state of power supplied to an actuator while suppressing a complicated configuration of the shift switching mechanism and an increase in cost. It is an object of the present invention to provide a control device for a shift switching mechanism that detects accurately.

  The control device for the shift switching mechanism according to the first invention is a control device for the shift switching mechanism that switches the shift position of the transmission by the rotational force of the actuator based on the electrical signal corresponding to the state of the operation member. The transmission has a plurality of shift positions. The shift switching mechanism is provided with a regulating member that regulates rotation of the actuator in a predetermined direction. The control device is configured to control the power supplied to the actuator based on the electric signal, the detecting means for detecting the rotation amount of the actuator, and the rotational position of the actuator regulated by the regulating member. A setting unit for setting the position of at least one shift position among the plurality of shift positions, and a limiting unit for limiting the power supplied to the actuator when setting the position of the shift position, And determining means for determining whether or not the limiting means is in an abnormal state based on the detected amount of rotation when setting the position of the shift position.

  According to the first invention, the determining means determines whether or not the limiting means (for example, the current limiting circuit) is in an abnormal state based on the detected rotation amount of the actuator when setting the position of the shift position. Judging. For example, if the electric power supplied to the actuator is not limited by the limiting means, the torque generated in the actuator may be larger than the normal torque generated when setting the position of the shift position. Therefore, the time change rate of the rotation amount when the actuator is further operated until it is balanced with the reaction force due to the elasticity at the time of deformation of the restricting member after the rotation of the actuator is restricted by the restricting member becomes larger than that at the normal time. That is, it can be determined whether or not the restricting means is in an abnormal state based on the time change rate of the rotation amount when the restricting member is deformed. For this reason, it is not necessary to newly provide a circuit for detecting whether or not the limiting means functions normally. Therefore, it is possible to provide a control device for the shift switching mechanism that can accurately detect an abnormal state of the electric power supplied to the actuator while suppressing a complicated configuration of the shift switching mechanism and an increase in cost.

  In the control device for the shift switching mechanism according to the second aspect of the invention, in addition to the configuration of the first aspect, the judging means may determine the amount of rotation detected after the change in the time change rate of the detected amount of rotation occurs. And a means for determining that the limiting means is in an abnormal state if it is equal to or greater than the set value.

  According to the second invention, if the electric power supplied to the actuator is not limited by the limiting means (for example, a current limiting circuit), the torque that is generated in the actuator is normal that is expressed when the position of the shift position is set. It may be larger than the torque at the time. Therefore, the time change rate of the rotation amount when the actuator is further operated until it is balanced with the reaction force due to the elasticity at the time of deformation of the restricting member after the rotation of the actuator is restricted by the restricting member becomes larger than that at the normal time. Furthermore, the position where the force based on the torque of the actuator and the reaction force due to elasticity at the time of deformation of the restricting member is a position where the amount of rotation after the rotation of the actuator is restricted by the restricting member becomes larger than normal. Therefore, when the rotation amount detected after the change in the time change rate of the rotation amount is equal to or greater than the set value, it can be determined that the limiting means is in an abnormal state.

  In the control device for the shift switching mechanism according to the third aspect of the invention, in addition to the configuration of the first aspect, the judging means can detect the amount of rotation detected after the change in the time change rate of the detected amount of rotation occurs. And means for determining that the limiting means is in an abnormal state when the time change rate is equal to or greater than the set value.

  According to the third invention, if the electric power supplied to the actuator is not limited by the limiting means (for example, a current limiting circuit), the torque generated in the actuator is normal expressed when setting the position of the shift position. It may be larger than the torque at the time. Therefore, the time change rate of the rotation amount when the actuator is further operated until the rotation of the actuator is regulated by the regulating member and further balanced with the reaction force due to the elasticity at the time of deformation of the regulating member becomes larger than normal. That is, it can be determined whether or not the restricting means is in an abnormal state based on the time change rate of the rotation amount when the restricting member is deformed.

  According to a fourth aspect of the present invention, there is provided a control device for a shift switching mechanism, in addition to the configuration of the third aspect of the invention, voltage detection means for detecting a voltage applied to the actuator, and a set value based on the detected voltage. And means for changing.

  According to the fourth invention, the torque developed in the actuator increases as the applied voltage increases. Therefore, the abnormal state can be detected with high accuracy by changing the set value based on the detected voltage.

  The control device for the shift switching mechanism according to the fifth aspect of the invention is based on the temperature detection means for detecting the physical quantity related to the temperature of the actuator and the detected physical quantity in addition to the configuration of the third invention. And means for changing the value.

  According to the fifth invention, in the case where the actuator is constituted by a rotating electrical machine, the coil resistance decreases as the coil portion is at a lower temperature, and thus torque generated in the actuator increases. Therefore, the abnormal state can be detected with high accuracy by changing the set value based on the physical quantity related to the temperature of the actuator (for example, the temperature of the actuator, the temperature of the hydraulic fluid of the transmission, or the outside temperature).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 shows a configuration of a shift control system 10 including a control device for a shift switching mechanism according to the present embodiment. Shift control system 10 according to the present embodiment is used for switching the shift position of a vehicle. The shift control system 10 includes a P switch 20, a shift switch 26, a vehicle power switch 28, a vehicle control device (hereinafter referred to as “EFI-ECU (Electronic Control Unit)”) 30, and a parking control device ( (Hereinafter referred to as “SBW (Shift By Wire) -ECU”) 40, actuator 42, encoder 46, shift switching mechanism 48, display unit 50, meter 52, drive mechanism 60, and battery voltage sensor 70. And a temperature sensor 80. The shift control system 10 functions as a shift-by-wire system that switches the shift position by electrical control. Specifically, the shift switching mechanism 48 is driven by the actuator 42 to switch the shift position. The control device for the shift switching mechanism according to the present embodiment is realized by SBW-ECU 40.

  The vehicle power switch 28 is a switch for switching on / off of the vehicle power. The vehicle power switch 28 is not particularly limited, and is, for example, an ignition switch. An instruction received from a user such as a driver by the vehicle power switch 28 is transmitted to the EFI-ECU 30. For example, when the vehicle power switch 28 is turned on, power is supplied from an auxiliary battery (not shown), and the shift control system 10 is activated.

  The P switch 20 is a switch for switching the shift position between a parking position (hereinafter referred to as “P position”) and a position other than parking (hereinafter referred to as “non-P position”). Includes an indicator 22 for indicating to the driver, and an input unit 24 for receiving an instruction from the driver. The driver inputs an instruction to put the shift position into the P position through the input unit 24. The input unit 24 may be a momentary switch. A P command signal indicating an instruction from the driver received by the input unit 24 is transmitted to the SBW-ECU 40. In addition, the shift position may be switched from the non-P position to the P position by means other than the P switch 20 described above.

  The SBW-ECU 40 controls the operation of the actuator 42 that drives the shift switching mechanism 48 in order to switch the shift position between the P position and the non-P position, and presents the current shift position state to the indicator 22. When the driver depresses the input unit 24 when the shift position is the non-P position, the SBW-ECU 40 switches the shift position to the P position and presents the indicator 22 that the current shift position is the P position.

  The actuator 42 is configured by a switched reluctance motor (hereinafter referred to as “SR motor”), and receives the actuator control signal from the SBW-ECU 40 to drive the shift switching mechanism 48. The encoder 46 rotates integrally with the actuator 42 and detects the rotation state of the SR motor. The encoder 46 of the present embodiment is a rotary encoder that outputs A-phase, B-phase, and Z-phase signals. The SBW-ECU 40 obtains a signal output from the encoder 46, grasps the rotation state of the SR motor, and controls energization for driving the SR motor.

  The shift switch 26 switches the shift position to a position such as a drive (D) position, a reverse (R) position, a neutral (N) position, a brake (B) position, or the P position when it is in the P position. It is a switch for canceling. A shift signal indicating an instruction from the driver received by the shift switch 26 is transmitted to the SBW-ECU 40. The SBW-ECU 40 performs control to switch the shift position in the drive mechanism 60 through the EFI-ECU 30 based on a shift signal indicating an instruction from the driver, and presents the current shift position state to the meter 52. The drive mechanism 60 is composed of a continuously variable transmission mechanism, but may be composed of a stepped transmission mechanism.

  The EFI-ECU 30 comprehensively manages the operation of the shift control system 10. Display unit 50 displays instructions, warnings, and the like for the driver issued by EFI-ECU 30 or SBW-ECU 40. The meter 52 presents the state of the vehicle equipment, the state of the shift position, and the like.

  The battery voltage sensor 70 detects the voltage of the auxiliary battery that supplies power to the actuator 42. Battery voltage sensor 70 transmits a signal indicating the detected voltage to EFI-ECU 30. Battery voltage sensor 70 may transmit a signal indicating the detected voltage to SBW-ECU 40. Further, the battery voltage sensor 70 may detect a voltage supplied from the auxiliary battery to the actuator 42.

  The temperature sensor 80 detects the temperature of hydraulic oil of a transmission (not shown). The temperature sensor 80 transmits a temperature detection signal indicating the detected temperature to the EFI-ECU 30. Note that the temperature sensor 80 may transmit a signal indicating the detected temperature to the SBW-ECU 40. The temperature sensor 80 only needs to be able to detect a physical quantity related to the temperature of the actuator 42. For example, the temperature sensor 80 may detect the outside air temperature or directly detect the temperature of the actuator 42. Also good.

  FIG. 2 shows the configuration of the shift switching mechanism 48. Hereinafter, the shift position means a P position and a non-P position, and will be described as not including the R, N, and D positions in the non-P position, but may include the R, N, and D positions. . That is, in this embodiment, a description will be given of a two-position configuration of a P position and a non-P position, but a four-position configuration of a P position and a non-P position that includes R, N, and D positions. May be.

  The shift switching mechanism 48 is fixed to the shaft 102 rotated by the actuator 42, the detent plate 100 rotating with the rotation of the shaft 102, the rod 104 operating with the rotation of the detent plate 100, and the output shaft of the transmission (not shown). A parking lock gear 108, a parking lock pole 106 for locking the parking lock gear 108, a detent spring 110 and a roller 112 for limiting the rotation of the detent plate 100 and fixing the shift position. The detent plate 100 is driven by the actuator 42 to switch the shift position. The encoder 46 functions as a counting unit that acquires a count value corresponding to the rotation amount of the actuator 42.

  FIG. 2 shows a state when the shift position is a non-P position. In this state, since the parking lock pole 106 does not lock the parking lock gear 108, the rotation of the drive shaft of the vehicle is not hindered. When the shaft 42 is rotated clockwise by the actuator 42 from this state, the rod 104 is pushed in the direction of the arrow A shown in FIG. 2 via the detent plate 100, and parking is performed by the taper portion provided at the tip of the rod 104. The lock pole 106 is pushed up in the direction of arrow B shown in FIG. As the detent plate 100 rotates, one of the two valleys provided at the top of the detent plate 100, that is, the roller 112 of the detent spring 110 at the non-P position position 120, climbs over the mountain 122 and passes through the other valley. That is, the process moves to the P position position 124. The roller 112 is provided on the detent spring 110 so as to be rotatable in its axial direction. When the detent plate 100 rotates until the roller 112 reaches the P position position 124, the parking lock pole 106 is pushed up to a position where the protruding portion of the parking lock pole 106 is fitted between the teeth of the parking lock gear 108. Thereby, the drive shaft of the vehicle is mechanically fixed, and the shift position is switched to the P position.

  In the shift control system 10 according to the present embodiment, the SBW-ECU 40 is operated by the detent spring in order to reduce the load on the components of the shift switching mechanism such as the detent plate 100, the detent spring 110, and the shaft 102 when the shift position is switched. The amount of rotation of the actuator 42 is controlled so as to reduce the impact when the 110 roller 112 falls over the mountain 122.

  In each valley of the detent plate 100, a surface located on the side away from the mountain 122 is called a wall. That is, the wall exists at a position where the roller 112 of the detent spring 110 collides with the roller 112 when the roller 112 of the detent spring 110 climbs over the mountain 122 and falls into the valley without performing the following control by the SBW-ECU 40. The wall at the P position position 124 is referred to as “P wall”, and the wall at the non-P position position 120 is referred to as “non-P wall”.

  When the roller 112 moves from the P position position 124 to the non-P position position 120, the SBW-ECU 40 causes the actuator so that the non-P wall 210 does not collide with the roller 112 or the impact force is alleviated even when the roller 112 collides. 42 is controlled. Specifically, the SBW-ECU 40 stops the rotation of the actuator 42 at a position before the non-P wall 210 collides with the roller 112. This position is referred to as a “non-P target rotational position”.

  Further, when the roller 112 moves from the non-P position position 120 to the P position position 124, the SBW-ECU 40 prevents the P wall 200 from colliding with the roller 112, or even if the collision occurs, the impact force is reduced. The actuator 42 is controlled. Specifically, the SBW-ECU 40 stops the rotation of the actuator 42 at a position before the P wall 200 collides with the roller 112. This position is called “P target rotation position”.

  By controlling the actuator 42 by the SBW-ECU 40, it is possible to significantly reduce the load related to the components of the shift switching mechanism such as the detent plate 100, the detent spring 110, and the shaft 102 at the time of shift position switching. By reducing the load, it is possible to reduce the weight and cost of the components of the shift switching mechanism. In the present embodiment, the cost of the components of the shift switching mechanism can be further reduced by performing the control described later.

  The actuator 42 rotates the detent plate 100 provided on the manual shaft 102. The P wall 200 and the non-P wall 210 formed on the detent plate 100 respectively restrict the rotation in a predetermined direction.

  The current shift position is determined when the rotation amount is within a predetermined rotation amount range from the P wall position or the non-P wall position.

  Specifically, the SBW-ECU 40 determines the rotation position of the actuator 42 (relative position of the roller 112 in the detent plate 100) based on the rotation amount detected by the encoder 46 from the P wall position to a predetermined position. When it is within the range of 1, it is determined that the shift position is the P position.

  On the other hand, when the rotation position of the actuator 42 is within the second range from the non-P wall position to a predetermined position based on the rotation amount detected by the encoder 46, the SBW-ECU 40 has a non-P shift position. Judge that it is a position.

  The SBW-ECU 40 calculates the absolute value of the difference between the counter value at the P wall position (or non-P wall position) and the counter value detected by the encoder 46 during the rotation of the actuator 42, thereby rotating the actuator 42. Is detected.

  Further, when the rotational position of the actuator 42 is neither in the first range nor in the second range, the SBW-ECU 40 determines that the shift position is indefinite or the shift is being switched.

  The P target rotation position is a position where the P wall 200 does not collide with the roller 112 of the detent spring 110 when switching from the non-P position to the P position, and is determined with a predetermined margin from the P wall position. The margin is set with a margin in consideration of looseness due to changes over time. As a result, a change with time can be absorbed if the number of times of use is a certain number of times, and a collision with the P wall 200 and 112 at the time of shift position switching can be avoided.

  The non-P target rotational position is a position where the non-P wall 210 does not collide with the roller 112 of the detent spring 110 when switching from the P position to the non-P position, and is determined with a predetermined margin from the non-P wall position. The margin is set with a margin in consideration of looseness due to changes over time, etc., and can be absorbed over time if it is used to some extent, avoiding collisions with non-P walls 210 and 112 at the time of shift position switching. can do. Note that the margin from the non-P wall position and the margin from the P wall position do not have to be the same, and may differ depending on the shape of the detent plate 100 and the like.

  As described above, the control method of the actuator 42 has been shown on the assumption that the P wall position and the non-P wall position are detected. The P wall position or the non-P wall position is a reference position for determining the shift position determination range and the target rotation position at the P position position 124 or the non-P position position 120. Hereinafter, a method of controlling the position of the actuator 42 using the encoder 46 that detects relative position information, specifically, a method of detecting the wall position serving as the reference position will be described.

  The SBW-ECU 40 functions as a control unit that rotates the actuator 42 and a setting unit that sets the P wall position of the actuator 42, that is, a reference position. In the P wall position detection control, first, the actuator 42 rotates the detent plate 100 in the clockwise direction, that is, in the direction in which the P wall 200 faces the roller 112 of the detent spring 110, thereby bringing the roller 112 and the P wall 200 into contact with each other. The P wall 200 functions as a regulating member that regulates the clockwise rotation of the actuator 42 at the P position. The P wall 200 may constitute a restricting member in cooperation with the detent spring 110 and the roller 112.

  That is, the SBW-ECU 40 sets the position of at least one shift position among the plurality of shift positions based on the rotational position of the actuator regulated by the regulating member.

  In FIG. 3, an arrow F <b> 1 indicates a rotational force by the actuator 42, an arrow F <b> 2 indicates a spring force by the detent spring 110, and an arrow F <b> 3 indicates a push-back force by the rod 104. A detent plate 100 ′ indicated by a dotted line indicates a position where the P wall 200 and 112 are in contact with each other. Therefore, detecting the position of the detent plate 100 ′ corresponds to detecting the position of the P wall 200.

  The detent plate 100 is rotated against the spring force of the detent spring 110 in the clockwise direction by the rotational force F1 of the actuator 42 from the position indicated by the dotted line even after contact with the P wall 200 and 112. As a result, the detent spring 110 is deflected, the spring force F2 is increased, and the pushing back force F3 by the rod 104 is also increased. The rotation of the detent plate 100 stops when the rotational force F1 is balanced with the spring force F2 and the pushing back force F3.

  The rotation stop of the detent plate 100 is determined based on the state of the count value acquired by the encoder 46. The SBW-ECU 40 determines whether the rotation of the detent plate 100 and the actuator 42 is stopped when the minimum value or the maximum value of the count value of the encoder 46 does not change for a predetermined time. Whether to monitor the minimum value or the maximum value of the count value may be set according to the encoder 46. In any case, the fact that the minimum value or the maximum value does not change for a predetermined time indicates that the detent plate 100 moves. Indicates a missing state.

  The SBW-ECU 40 detects the position of the detent plate 100 when the rotation is stopped as a provisional P wall position (hereinafter referred to as “provisional P wall position”), and calculates a deflection amount or a deflection angle of the detent spring 110. . The calculation of the deflection amount or the deflection angle is performed using a map that is held in advance in the SBW-ECU 40 and shows the relationship between the deflection amount or the deflection angle corresponding to the voltage applied to the actuator 42. The SBW-ECU 40 calculates a deflection amount or a deflection angle corresponding to the voltage applied to the actuator 42 when the temporary P wall position is detected from the map. Instead of the applied voltage of the actuator 42, a map using a battery voltage may be used. The battery voltage is monitored by the SBW-ECU 40 through the EFI-ECU 30, and can be easily detected. In this case, the map is created in consideration of the voltage drop due to the wire harness from the battery to the actuator 42. The SBW-ECU 40 uses this map to map-correct the temporary P wall position from the calculated deflection amount or deflection angle, and determines the map corrected position as the P wall position. The P target rotational position can be set by determining the P wall position. Instead of the map indicating the relationship between the deflection amount or the deflection angle with respect to the applied voltage, a map indicating the relationship between the deflection amount or the deflection angle corresponding to the output torque of the actuator 42 may be used. Instead, a sensor that detects the amount of deflection or the angle of deflection may be provided to detect it.

  The setting of the non-P wall position is the same as the method for setting the P wall position. Therefore, detailed description will not be repeated.

  As described above, the shift control system 10 rotates the actuator 42 to bring the wall of the detent plate 100 into contact with the roller 112 of the detent spring 110. Then, by detecting the contact position, the wall position of the detent plate 100 corresponding to the reference position of the shift position is detected. By setting this wall position as the reference position, the rotation of the actuator 42 can be appropriately controlled even when using the encoder 46 that can detect only relative position information. That is, the shift position can be appropriately switched without using a neutral start switch or the like.

  In the shift control system 10 having the above-described configuration, when an actuator having high output characteristics is selected for the purpose of improving the response of the shift switching mechanism 48, the deformation due to the load relating to the components of the shift switching mechanism 48 is changed. Such adverse effects as the above may occur.

  For example, if a high output torque is applied to the detent spring 110 from the actuator during the above-described wall contact control, the detent spring 110 may be greatly deformed or durability may be deteriorated.

  Therefore, as shown by the solid line in FIG. 4A, a current limiting circuit is provided so that the current supplied to the actuator 42 falls within a predetermined range (range from I (1) to I (2)). It is conceivable to use it to cut the current. In the present embodiment, the current limiting circuit is described as being provided as hardware inside the SBW-ECU 40, but may be provided outside the SBW-ECU 40.

  When the current supplied to the actuator 42 by the current limiting circuit exceeds the predetermined current I (1), the current decreases (current cut), and when the current decreases below the predetermined current I (2), the current Increases (current on), limiting the magnitude of the current. Therefore, as shown by the solid line in FIG. 4B, the actuator torque can be maintained at Ta (1) indicating a normal value.

  Note that the current limit circuit is not limited to limit the current supplied to the actuator 42 so as to be within a predetermined range. For example, the current limit circuit has a value equal to or greater than a predetermined value. It may be a circuit that limits the magnitude of the current so that the current flows to the actuator 42 constantly.

  However, when some abnormality occurs in the current limiting circuit and current cut cannot be performed, the actuator 42 has a current of I (3) larger than I (1) as shown by the broken line in FIG. Flows to the actuator 42. Therefore, as shown by the broken line in FIG. 4B, the actuator torque is maintained at Ta (3) which is larger than Ta (1) indicating a normal value. Therefore, the detent spring 110 may be plastically deformed or durability may be deteriorated.

  On the other hand, it is conceivable to provide an abnormality determination circuit for determining whether or not the current limiting circuit is normal. However, if an abnormality determining circuit is provided in addition to the current limiting circuit, the configuration of the shift switching mechanism May become complicated and cost may increase.

  Therefore, according to the present invention, the SBW-ECU 40 determines whether or not the current limiting circuit is in an abnormal state based on the rotation amount of the actuator 42 detected by the encoder 46 when setting the position of the shift position. Characterized by points.

  FIG. 5 shows a functional block diagram of SBW-ECU 40 that is the control device for the shift switching mechanism according to the present embodiment.

  The SBW-ECU 40 includes an input interface (hereinafter referred to as input I / F) 300, an arithmetic processing unit 400, a communication unit 700, a storage unit 600, and an output interface (hereinafter referred to as output I / F). 500.

  The input I / F 300 receives the P command signal from the P switch 20, the count signal from the encoder 46, and the shift signal from the shift switch 26, and transmits them to the arithmetic processing unit 400.

  Communication unit 700 is connected to EFI-ECU 30 using a communication line (not shown). Communication unit 700 receives a battery voltage detection signal and a temperature detection signal from EFI-ECU 30 and transmits them to arithmetic processing unit 400.

  The arithmetic processing unit 400 includes a wall pad control unit 402, a speed change determination unit 404, an abnormality determination unit 406, and a display control unit 408.

  The wall contact control unit 402 performs wall contact control for setting the P wall position and the non-P wall position as described above when a predetermined condition is established for the vehicle state. The “predetermined condition” may be, for example, a condition that the P position and the non-P position are switched over a predetermined number of times or a predetermined number of trips. Alternatively, it may be a condition that the vehicle power switch 28 is turned on, and is not particularly limited. “1 trip” refers to the time from when the vehicle power switch 28 is turned on to when it is turned off.

  Note that the number of switching times or the number of trips may be counted by the arithmetic processing unit 400 and stored in the storage unit 600 each time switching is performed or the vehicle power switch 28 is turned on. For example, when it is determined that the wall contact control is being performed, the wall contact control unit 402 may turn on the wall contact determination flag.

  The speed change determination unit 404 determines whether or not the temporal change rate of the rotation amount of the actuator 42 changes based on the count signal detected by the encoder 46 when the wall contact control is being performed.

  For example, the speed change determination unit 404 determines whether the time change rate of the rotation amount of the actuator 42 changes based on the counter value detected by the encoder 46. The speed change determination unit 404 determines that the absolute value of the difference between the time change rate of the counter value calculated in the previous calculation cycle and the time change rate of the counter value calculated in the current calculation cycle is greater than or equal to a predetermined value. If there is, it is determined that the time change rate of the rotation amount of the actuator 42 has changed. Here, the time change rate of the rotation amount of the actuator 42 corresponds to the absolute value of the time change rate of the counter value.

  As the time change rate of the counter value, the time change rate between one calculation cycle may be calculated, or the time change rate may be calculated retroactively to a predetermined period.

  For example, the speed change determination unit 404 may determine whether or not the time change rate of the counter value changes on condition that the wall contact determination flag is on. Further, for example, when the speed change determination unit 404 determines that the time change rate of the rotation amount of the actuator 42 has changed, the speed change determination flag may be turned on.

  Abnormality determination unit 406 determines whether the current limiting circuit is in a normal state based on the calculated time change rate of the rotation amount of actuator 42 and the set values corresponding to battery voltage V and temperature TH of the transmission hydraulic fluid. Determine whether or not. For example, the abnormality determination unit 406 determines that the calculated time change rate of the rotation amount of the actuator 42 (absolute value of the time change rate of the counter value) is a function ΔCNT (between the battery voltage V and the transmission oil temperature TH). It is determined whether it is smaller than the set value calculated by (V, TH).

  FIG. 6 shows the relationship between temperature and actuator torque when the vertical axis is the actuator torque and the horizontal axis is the temperature of the hydraulic fluid of the transmission. As shown in FIG. 6, for example, when the actuator 42 is operated under the same conditions except for the temperature of the transmission hydraulic fluid, the torque generated in the actuator 42 decreases as the transmission hydraulic fluid temperature increases. Thus, the lower the temperature of the hydraulic fluid of the transmission, the higher the torque developed in the actuator 42. This is because the temperature of the actuator 42 decreases as the temperature of the hydraulic fluid of the transmission decreases. Therefore, the coil resistance of the actuator 42 is reduced.

  FIG. 7 shows the relationship between the voltage and the actuator torque when the vertical axis is the actuator torque and the horizontal axis is the battery voltage. As shown by the solid line in FIG. 7, for example, when the actuator 42 is operated under the same conditions except for the battery voltage, the higher the battery voltage, the higher the torque expressed in the actuator 42, and the lower the battery voltage, The torque developed in the actuator 42 has a proportional relationship that decreases. Note that, as shown by the broken line in FIG. 7, the lower the operating oil of the transmission, the higher the torque developed in the actuator 42, even at the same battery voltage, and the higher the operating oil of the transmission, The torque developed at 42 tends to be low even at the same battery voltage.

  The function ΔCNT (V, TH) is set based on the relationship between the temperature and the actuator torque and the relationship between the battery voltage and the actuator torque as shown in FIGS. Note that the set value may be calculated from a map, a mathematical expression, or a table instead of the function ΔCNT (V, TH).

  Abnormality determination unit 406 determines that the current limiting circuit is in a normal state when the calculated time change rate of the rotation amount of actuator 42 is smaller than the set value. Abnormality determination unit 406 determines that the current limiting circuit is in an abnormal state when the calculated time change rate of the rotation amount of actuator 42 is equal to or greater than a set value.

  Note that the abnormality determination unit 406 may turn on the abnormality determination flag when determining that the current limiting circuit is in an abnormal state, for example.

  When it is determined that the current limiting circuit is in an abnormal state, the display control unit 408 generates a lighting control signal so that the warning lamp is lit, and transmits it to the indicator 22 via the output I / F 500. . Note that the display control 408 may generate the lighting control signal so that the warning lamp lights up on condition that the abnormality determination flag is on.

  In this embodiment, the wall pad control unit 402, the speed change determination unit 404, the abnormality determination unit 406, and the display control unit 408 are all stored in the storage unit 600 by a CPU (Central Processing Unit) that is the arithmetic processing unit 400. Although the description will be made assuming that the program is realized by executing a stored program and functions as software, it may be realized by hardware. Such a program is recorded on a recording medium and mounted on the vehicle.

  Various information, programs, threshold values, maps, and the like are stored in the storage unit 600, and data is read or stored from the arithmetic processing unit 400 as necessary.

  Hereinafter, with reference to FIG. 8, a control structure of a program executed by SBW-ECU 40 which is the control device for the shift switching mechanism according to the present embodiment will be described.

  In step (hereinafter, step is referred to as S) 100, SBW-ECU 40 determines whether or not wall pad control is being performed. For example, the SBW-ECU 40 may determine that the wall contact control is being performed when the wall contact determination flag is on. If the wall pad control is in progress (YES in S100), the process proceeds to S102. Otherwise (NO in S100), this process ends.

  In S102, SBW-ECU 40 determines whether the time change rate of the counter value has changed. Specifically, the SBW-ECU 40 determines whether the time change rate of the counter value has changed. If there is a speed change in the time change rate of the counter value (YES in S102), the process proceeds to S104. Otherwise (NO in S102), this process ends.

  In S104, SBW-ECU 40 detects battery voltage V based on the battery voltage detection signal received through EFI-ECU 30.

  In S106, SBW-ECU 40 detects the temperature TH of the hydraulic oil in the transmission based on the temperature detection signal received through EFI-ECU 30.

  In S108, SBW-ECU 40 determines whether or not the absolute value of the time change rate of the counter value is smaller than a value ΔCNT (V, TH) calculated based on battery voltage V and temperature TH. If the absolute value of the time change rate of the counter value is smaller than ΔCNT (V, TH) (YES in S108), this process ends. If not (NO in S108), the process proceeds to S110.

  In S110, SBW-ECU 40 performs an abnormality warning display process. Specifically, the SBW-ECU 40 controls the indicator 22 so that a warning lamp is lit.

  The operation of SBW-ECU 40, which is the control device for the shift switching mechanism according to the present embodiment, based on the above-described structure and flowchart will be described with reference to FIG.

  When wall contact control is started at time T ′ (0) (YES in S100), it is determined whether or not the time change rate of the counter value has changed (S102).

  When the roller 112 contacts the wall at the P position position 124 or the non-P position position 120 at time T ′ (1), the detent spring 110 starts to bend. At this time, since the reaction force due to the bending of the detent spring 110 is applied to the actuator 42, the time change rate of the counter value changes (YES in S102).

  For example, as indicated by the solid line in FIG. 9, the absolute value of the time change rate of the counter value from C (1) to C (2) from time T ′ (1) to time T ′ (2) is detected. If the value is smaller than the value calculated from the detected battery voltage V (S104), the detected temperature of hydraulic oil in the transmission (S106), and the function ΔCNT (V, TH) (YES in S108), the current limiting circuit It is determined that the state is normal.

  On the other hand, as indicated by the broken line in FIG. 9, from time T ′ (1) to time T ′ (3), the absolute value of the time change rate of the counter value from CC (1) to C (3) is detected. If the detected battery voltage V (S104) is greater than the detected hydraulic oil temperature (S106) and the function ΔCNT (V, TH) (NO in S108), the current limiting circuit is in an abnormal state. Is determined and the warning lamp of the indicator 22 is turned on (S110).

  As described above, according to the control device for the shift switching mechanism according to the present embodiment, when setting the position of the shift position, the current limiting circuit is in an abnormal state based on the time change rate of the rotation amount of the actuator. It can be determined whether or not there is. Therefore, it is not necessary to newly provide a circuit for detecting whether or not the current limiting circuit is functioning normally. Therefore, it is possible to provide a control device for the shift switching mechanism that can accurately detect an abnormal state of the electric power supplied to the actuator while suppressing a complicated configuration of the shift switching mechanism and an increase in cost.

  Further, in the present embodiment, whether or not the current limiting circuit is in an abnormal state based on the time change rate after the detent spring starts to bend, that is, after the time change rate of the counter value has changed. However, it is determined whether or not the current limiting circuit is in an abnormal state based on the rotation amount (counter value) of the actuator after the change in the time change rate of the counter value occurs. Also good. For example, the counter value when the reaction force from the detent spring and the force based on the actuator torque are balanced, that is, the counter value at the time when the time change rate of the counter value becomes substantially zero during wall contact control is greater than or equal to the set value (the detent plate is If the counter value increases in the positive direction when rotating to the wall contact side), it may be determined that the current limiting circuit is in an abnormal state.

  As shown by the solid line in FIG. 9, the time change rate of the counter value becomes substantially zero at time T ′ (2). At this time, the bending of the detent spring 110 is completed. That is, the resultant force of the rotational force of the actuator, the reaction force due to the bending of the detent spring 110, and the force for the parking lock pole to return becomes substantially zero. At this time, if counter value C (2) is smaller than the set value, SBW-ECU 40 determines that the current limiting circuit is in a normal state.

  Then, as indicated by the broken line in FIG. 9, if the counter value C (3) is greater than or equal to the set value at the time point when the time change rate of the counter value becomes substantially zero at time T ′ (3), the SBW-ECU 40 Then, it is determined that the current limiting circuit is in an abnormal state.

  The set value may be changed according to the battery voltage and / or the temperature of the hydraulic fluid of the transmission. In addition, when the counter value increases in the negative direction when the detent plate rotates to the wall contact side, the counter value at the time when the time change rate of the counter value becomes substantially zero during the wall contact control is equal to or less than the set value. Then, it can be determined that the current limiting circuit is in an abnormal state.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the structure of the shift control system 10 which concerns on this Embodiment. It is a figure which shows the structure of the shift switching mechanism of FIG. It is a figure which shows the change of the detent spring at the time of P wall application. It is a timing chart which shows the change of the current which flows into an actuator, and the torque which expresses in an actuator. It is a functional block diagram of SBW-ECU which is a control device of the shift switching mechanism according to the present embodiment. It is a figure which shows the relationship between an actuator torque and the temperature of the hydraulic fluid of a transmission. It is a figure which shows the relationship between an actuator torque and a battery voltage. It is a flowchart which shows the control structure of the program performed by SBW-ECU which is a control apparatus of the shift switching mechanism which concerns on this Embodiment. It is a timing chart which shows the change of the count value detected by an encoder.

Explanation of symbols

  20 P switch, 22 indicator, 24 input section, 26 shift switch, 28 vehicle power switch, 30 EFI-ECU, 40 SBW-ECU, 42 actuator, 46 encoder, 48 shift switching mechanism, 50 display section, 52 meter, 60 drive Mechanism, 70 Battery voltage sensor, 80 Temperature sensor, 100 Detent plate, 102 Shaft, 104 Rod, 106 Parking lock pole, 108 Parking lock gear, 110 Detent spring, 112 Roller, 120 Non-P position position, 122 Mountain, 124 P position Position, 200 P wall, 210 non-P wall, 300 input I / F, 400 arithmetic processing unit, 402 wall contact control unit, 404 speed change determination unit, 406 abnormality determination unit, 408 display control unit, 500 Output I / F, 600 storage unit.

Claims (5)

A control device of a shift switching mechanism that switches a shift position of a transmission based on an electric signal corresponding to a state of an operation member by a rotational force of an actuator, wherein the transmission has a plurality of shift positions, and the shift The switching mechanism is provided with a regulating member that regulates rotation of the actuator in a predetermined direction,
Control means for controlling power supplied to the actuator based on the electrical signal;
Detection means for detecting the amount of rotation of the actuator;
Setting means for setting the position of at least one of the plurality of shift positions based on the rotational position of the actuator regulated by the regulating member;
Limiting means for limiting the power supplied to the actuator when setting the position of the shift position;
A control device for a shift switching mechanism, comprising: a determining unit configured to determine whether the limiting unit is in an abnormal state based on the detected rotation amount when setting the position of the shift position.   The determination means is means for determining that the limiting means is in an abnormal state when the detected rotation amount after the change in the time change rate of the detected rotation amount is a set value or more. The control device for the shift switching mechanism according to claim 1, comprising:   The determining means determines that the limiting means is in an abnormal state when the time change rate of the rotation amount detected after the change in the time change rate of the detected rotation amount becomes equal to or greater than a set value. The control device for the shift switching mechanism according to claim 1, further comprising: The controller is
Voltage detection means for detecting a voltage applied to the actuator;
The control device for a shift switching mechanism according to claim 3, further comprising means for changing the set value based on the detected voltage. The controller is
Temperature detecting means for detecting a physical quantity related to the temperature of the actuator;
The control device for a shift switching mechanism according to claim 3, further comprising means for changing the set value based on the detected physical quantity.

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