JP2018146090A - Failure diagnosis device and failure diagnosis method of hydraulic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a failure diagnosis device and failure diagnosis method of a hydraulic system, capable of properly executing failure diagnosis, in the hydraulic system including an electromagnetic proportional valve to which a control signal overlapped with a dither signal is output.SOLUTION: A failure diagnosis device includes of a hydraulic system includes an electromagnetic proportional valve configured to adjust control oil pressure supplied to a hydraulic chamber of a pulley of a continuously variable transmission. The failure diagnosis device includes a failure diagnosis unit configured to acquire information on a condition of a dither signal overlapped with a control signal of the electromagnetic proportional valve set based on information on amplitude of the control oil pressure, and perform failure diagnosis in the hydraulic system by comparing the condition of the dither signal with a pre-created dither reference model.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a failure diagnosis apparatus and failure diagnosis method for a hydraulic system.

  Continuously variable transmission (hereinafter also referred to as “CVT (Continuously Variable Transmission)”) allows continuous gear ratio switching by changing the groove width of the primary pulley and secondary pulley around which the belt or chain is wound. This is a transmission. The groove width of each pulley of the continuously variable transmission is variable by adjusting the control hydraulic pressure supplied to the hydraulic chamber. In a hydraulic system that supplies a control hydraulic pressure to the hydraulic chamber of each pulley of the continuously variable transmission, the control hydraulic pressure is adjusted by controlling the current supplied to the electromagnetic proportional valve. The electromagnetic proportional valve can generate hysteresis due to sliding friction of the armature (movable iron core) or electromagnetic factors. For this reason, in a hydraulic system including an electromagnetic proportional valve, a dither signal is superimposed on a control signal of the electromagnetic proportional valve in order to reduce hysteresis of the electromagnetic proportional valve. By adding the dither signal, the armature of the electromagnetic proportional valve slightly vibrates, and the hysteresis due to the sliding friction of the armature and electromagnetic factors can be reduced.

  Here, in Patent Document 1, in executing the control for setting the condition of the dither signal based on the target oil pressure of the oil passage and the oil temperature, the dither signal is based on the differential pressure between the detected oil pressure of the oil passage and the command oil pressure. In addition, there is disclosed a technique for updating the condition of the dither signal and stopping the update of the condition of the dither signal when the change amount of the detected hydraulic pressure within a predetermined time exceeds a certain amount.

JP 2014-105805 A

  However, in the technique described in Patent Document 1, the update of the dither signal condition is stopped by comparing the differential pressure between the detected hydraulic pressure and the command hydraulic pressure with a certain threshold value. In some cases, the condition of the dither signal cannot be set properly because the change in the signal cannot be taken into consideration.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a hydraulic system failure diagnosis apparatus and failure that can appropriately perform failure diagnosis of a hydraulic system including an electromagnetic proportional valve that outputs a control signal on which a dither signal is superimposed. An object is to provide a diagnostic method.

  According to the present invention, in a failure diagnosis apparatus for a hydraulic system having an electromagnetic proportional valve that adjusts a control hydraulic pressure supplied to a hydraulic chamber of a pulley of a continuously variable transmission, an electromagnetic wave set based on amplitude information of the control hydraulic pressure A hydraulic system including a failure diagnosis unit that obtains information on the condition of the dither signal to be superimposed on the control signal of the proportional valve and compares the condition of the dither signal with a previously created dither reference model to diagnose the failure of the hydraulic system A fault diagnosis apparatus is provided.

  According to the present invention, in the failure diagnosis method for a hydraulic system having an electromagnetic proportional valve that adjusts the control hydraulic pressure supplied to the hydraulic chamber of the pulley of the continuously variable transmission, it is set based on the amplitude information of the control hydraulic pressure. Obtaining information on the condition of the dither signal to be superimposed on the control signal of the electromagnetic proportional valve, and performing a fault diagnosis of the hydraulic system by comparing the condition of the dither signal with a dither reference model created in advance. A fault diagnosis method for a hydraulic system is provided.

  As described above, according to the present invention, it is possible to appropriately execute failure diagnosis of a hydraulic system including an electromagnetic proportional valve that outputs a control signal on which a dither signal is superimposed.

It is a schematic diagram of the hydraulic system which supplies control hydraulic pressure to the hydraulic chamber of the pulley of an automatic transmission mechanism. It is a block diagram which shows the structural example of the control apparatus (failure diagnostic apparatus) of the electromagnetic proportional valve which concerns on embodiment of this invention. It is a flowchart which shows the control processing of the electromagnetic proportional valve which concerns on the same embodiment. It is explanatory drawing which shows the setting method of the conditions of the dither signal by the control apparatus of the electromagnetic proportional valve which concerns on the embodiment. It is explanatory drawing which shows the relationship between the difference of the hydraulic amplitude which concerns on the same embodiment, and the correction amount of a dither signal. It is explanatory drawing which shows the relationship between a gear change state and control hydraulic-pressure hysteresis. It is explanatory drawing which shows the relationship between an electric current value and electromagnetic force hysteresis. It is explanatory drawing which shows the relationship between the magnitude | size of control oil pressure, and control oil pressure hysteresis. It is a flowchart which shows the setting process of the condition of the dither signal which concerns on the same embodiment. It is a flowchart which shows the setting process of the 1st dither correction amount based on the hydraulic pressure amplitude which concerns on the same embodiment. It is a flowchart which shows the setting process of the 2nd dither correction amount based on the speed change state which concerns on the same embodiment. It is a flowchart which shows the setting process of the 3rd dither correction amount based on the request | requirement electric current value and target hydraulic pressure which concern on the embodiment. It is a flowchart which shows an example of the failure diagnosis process of the hydraulic system which concerns on the embodiment. It is a flowchart which shows the reference example of the failure diagnosis process of the hydraulic system which concerns on the same embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

<1. Hydraulic system>
(1-1. Configuration example of hydraulic system)
A configuration example of a hydraulic system 10 to which a control device (failure diagnosis device) for an electromagnetic proportional valve according to an embodiment of the present invention can be applied will be described with reference to FIG. FIG. 1 shows an example of a hydraulic system 10 for controlling the CVT transmission ratio of a vehicle such as an automobile. The hydraulic system 10 controls the transmission ratio by changing the winding diameter of the belt or chain wound around each pulley by controlling the control hydraulic pressure supplied to the hydraulic chamber 11P of the primary pulley of the CVT and the hydraulic chamber 11S of the secondary pulley. . Each pulley has, for example, a fixed sheave and a movable sheave. The movable sheave thrust moves in accordance with the hydraulic pressure in the hydraulic chamber 11S and the groove width of the pulley changes, whereby the winding diameter of the belt or the like changes.

  The hydraulic system 10 includes a pump 51, a first electromagnetic proportional valve 13P, a first pressure control valve 17P, a second electromagnetic proportional valve 13S, a second pressure control valve 17S, and a first pressure sensor 25P. And a second pressure sensor 25S. The pump 51 is driven using, for example, the output of the engine of the vehicle, and supplies hydraulic oil to the hydraulic chamber 11P and the hydraulic chamber 11S. The discharge port 51 a of the pump 51 is connected to the discharge line 53. The first pressure sensor 25P detects the control hydraulic pressure supplied to the hydraulic chamber 11P of the primary pulley. The second pressure sensor 25S detects the control hydraulic pressure supplied to the hydraulic chamber 11S of the secondary pulley.

  Control of the control hydraulic pressure supplied to the hydraulic chamber 11P of the primary pulley is performed by the first pressure control valve 17P and the first electromagnetic proportional valve 13P. The first pressure control valve 17P controls the hydraulic pressure supplied to the hydraulic chamber 11P by switching on / off the supply of hydraulic oil from the pump 51 to the hydraulic chamber 11P. The first pressure control valve 17P is a pilot operated valve and is a switching valve that switches the piston 19P to two positions. When the piston 19P of the first pressure control valve 17P is in the illustrated first position, the discharge line 53 and the pressure line 23P leading to the hydraulic chamber 11P are cut off, and the pressure line 23P and the tank 59 communicate. When the piston 19P of the first pressure control valve 17P is in the second position, the discharge line 53 and the pressure line 23P communicate with each other.

  The first electromagnetic proportional valve 13P is a switching valve that switches the piston 15P to two positions, and pilot-operates the first pressure control valve 17P. The first electromagnetic proportional valve 13P is driven by a control device (not shown). When the first electromagnetic proportional valve 13P is not energized, the position of the piston 15P is at the first position shown in the figure, and when the first electromagnetic proportional valve 13P is energized, the piston 15P moves to the left side of the figure and the position of the piston 15P is changed. Switch to the second position. When the piston 15P of the first electromagnetic proportional valve 13P is in the illustrated first position, the discharge line 53 and the pilot pressure supply line 21P are cut off, and the pilot pressure supply line 21P and the tank 59 communicate with each other. When the piston 15P of the first electromagnetic proportional valve 13P is in the second position, the discharge line 53 and the pilot pressure supply line 21P communicate with each other.

  Control of the control hydraulic pressure supplied to the hydraulic chamber 11S of the secondary pulley is performed by the second pressure control valve 17S and the second electromagnetic proportional valve 13S. The second pressure control valve 17S controls the hydraulic pressure supplied to the hydraulic chamber 11S by switching on / off the supply of hydraulic oil from the pump 51 to the hydraulic chamber 11S. The second pressure control valve 17S is a pilot operated valve and is a switching valve that switches the piston 19S to two positions. When the piston 19S of the second pressure control valve 17S is in the illustrated first position, the discharge line 53 and the pressure line 23S communicating with the hydraulic chamber 11S communicate with each other. When the piston 19S of the second pressure control valve 17S is in the second position, the discharge line 53 and the pressure line 23S are cut off, and the pressure line 23S and the tank 59 are communicated.

  The second electromagnetic proportional valve 13S is a switching valve that switches the piston 15S between two positions, and pilot-operates the second pressure control valve 17S. The second electromagnetic proportional valve 13S is driven by a control device (not shown). When the second electromagnetic proportional valve 13S is not energized, the position of the piston 15S is at the first position shown in the figure, and when the second electromagnetic proportional valve 13S is energized, the piston 15S moves to the left side of the figure and the position of the piston 15S is changed. Switch to the second position. When the piston 15S of the second electromagnetic proportional valve 13S is in the illustrated first position, the discharge line 53 and the pilot pressure supply line 21S communicate with each other. When the piston 15S of the second electromagnetic proportional valve 13S is in the second position, the discharge line 53 and the pilot pressure supply line 21S are cut off, and the pilot pressure supply line 21S and the tank 59 are communicated.

(1-2. Operation example of hydraulic system)
The hydraulic system 10 operates as follows. When the engine starts and the pump 51 operates, the pump 51 discharges hydraulic oil to the discharge line 53. The hydraulic oil discharged to the discharge line 53 is supplied to the first pressure control valve 17P, the first electromagnetic proportional valve 13P, the second pressure control valve 17S, and the second electromagnetic proportional valve 13S. In the illustrated hydraulic system 10, when increasing the transmission ratio of CVT, the energization amount to the first electromagnetic proportional valve 13P and the second electromagnetic proportional valve 13S is increased. When the energization amount to the first electromagnetic proportional valve 13P increases, the position of the piston 15P switches from the illustrated first position to the second position. Then, hydraulic fluid is supplied to the first pressure control valve 17P through the pilot pressure supply line 21P. The pressure of the hydraulic oil becomes a pilot pressure, and the position of the piston 19P of the first pressure control valve 17P is switched from the illustrated first position to the second position. As a result, hydraulic fluid is supplied to the hydraulic chamber 11P via the first pressure control valve 17P and the pressure line 23P, and the hydraulic pressure in the hydraulic chamber 11P increases.

  On the other hand, when the energization amount to the second electromagnetic proportional valve 13S increases, the position of the piston 15S switches from the illustrated first position to the second position. Then, the hydraulic oil in the pilot pressure supply line 21S is returned to the tank 59, and the pilot pressure in the second pressure control valve 17S is reduced. Therefore, the position of the piston 19S of the second pressure control valve 17S is switched from the illustrated first position to the second position. As a result, the hydraulic oil in the hydraulic chamber 11S is returned to the tank 59 via the pressure line 23S and the second pressure control valve 17S, and the hydraulic pressure in the hydraulic chamber 11S decreases.

  Further, in the illustrated hydraulic system 10, when the CVT gear ratio is reduced, the energization amount to the first electromagnetic proportional valve 13P and the second electromagnetic proportional valve 13S is decreased. When the energization amount to the first electromagnetic proportional valve 13P is decreased, the position of the piston 15P is returned to the illustrated first position. Then, the hydraulic oil in the pilot pressure supply line 21P is returned to the tank 59, and the pilot pressure in the first pressure control valve 17P is reduced. Therefore, the position of the piston 19P of the first pressure control valve 17P is returned to the illustrated first position. As a result, the hydraulic oil in the hydraulic chamber 11P is returned to the tank 59 via the pressure line 23P and the first pressure control valve 17P, and the hydraulic pressure in the hydraulic chamber 11P decreases.

  On the other hand, when the energization amount of the second electromagnetic proportional valve 13S is decreased, the position of the piston 15S is returned to the illustrated first position. Then, hydraulic fluid is supplied to the second pressure control valve 17S via the pilot pressure supply line 21S. The pressure of the hydraulic oil becomes a pilot pressure, and the position of the piston 19S of the second pressure control valve 17S is returned to the illustrated first position. As a result, hydraulic oil is supplied to the hydraulic chamber 11S via the second pressure control valve 17S and the pressure line 23S, and the hydraulic pressure in the hydraulic chamber 11S increases.

<2. Configuration example of control device (failure diagnosis device)>
Next, a configuration example of the control device for the electromagnetic proportional valve according to the present embodiment will be described. In the following description, the first electromagnetic proportional valve 13P and the second electromagnetic proportional valve 13S are expressed as an electromagnetic proportional valve 13 without being distinguished, and the hydraulic chambers 11P and 11S are expressed as a hydraulic chamber 11 without being distinguished. The first pressure sensor 25P and the second pressure sensor 25S are expressed as the pressure sensor 25 without being distinguished from each other. In the present embodiment, the control device for the electromagnetic proportional valve corresponds to a failure diagnosis device.

  FIG. 2 shows a configuration example of the control device 100 for the electromagnetic proportional valve. The control device 100 includes a control unit 110 including a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), a storage unit 130, and an electromagnetic proportional valve drive unit 135 including a drive circuit. The control unit 110 includes an acquisition unit 111, a hydraulic amplitude calculation unit 113, a dither setting unit 115, an electromagnetic proportional valve control unit 117, and a failure diagnosis unit 119. Each of these units has a function realized by executing a software program by the processor.

  The storage unit 130 may include a storage element such as a ROM (Read Only Memory) that stores software programs, control parameters, and the like, and a RAM (Random Access Memory) that stores information obtained, information on control parameters, calculation processing results, and the like. . The storage unit 130 may include a storage device using another storage medium such as a CD-ROM or a storage device. Note that a part or all of the control unit 110 may be configured by an updatable firmware such as a firmware in addition to a processor such as a CPU or MPU, and may be executed by a command from the CPU or the like. It may be a module or the like.

  The acquisition unit 111 acquires information used for arithmetic processing from a sensor or other control device. In the present embodiment, the acquisition unit 111 acquires information on the control hydraulic pressure P_det detected by the pressure sensor 25. For example, the acquisition unit 111 acquires information on the control oil pressure P_det detected at a time interval that can calculate the oil pressure amplitude value Ap_act caused by at least the dither signal superimposed on the control signal of the electromagnetic proportional valve 13. The acquisition unit 111 may receive information on the control hydraulic pressure P_det directly from the pressure sensor 25, or may receive it via another control device (not shown).

  Further, the acquisition unit 111 may acquire CVT shift state information such as a vehicle acceleration command value Acc_cmd, a CVT shift speed command value Vc_cmd, and a hydraulic pressure change rate command value Rp_cmd. The CVT shift speed command value Vc_cmd and the hydraulic pressure change rate command value Rp_cmd are values set based on information such as a vehicle acceleration request, engine speed, and engine torque, for example. The acquisition unit 111 may receive information on these shift states from a control device (not shown) that controls the driving force of the vehicle, for example. Further, the acquisition unit 111 may receive information on the required current value I_tgt and the target hydraulic pressure P_tgt of the electromagnetic proportional valve 13. In addition, the acquisition unit 111 includes information on the line pressure supplied to the electromagnetic proportional valve 13 and the pressure control valve 17, information on the oil temperature of the hydraulic oil, information on the temperature of the electromagnetic proportional valve 13, and information on the atmospheric temperature of the hydraulic system 10. May be obtained. Note that “acquiring” information with the acquisition unit 111 includes not only acquiring sensor output information or information calculated by other units of the control device 100, but also calculating information with the acquisition unit 111 itself. Including seeking.

  The hydraulic amplitude calculation unit 113 calculates the hydraulic amplitude value Ap_act based on the information of the control hydraulic pressure P_det acquired by the acquisition unit 111. The calculated hydraulic amplitude value Ap_act is used as information on the magnitude of the amplitude of the control hydraulic pressure P_det resulting from the dither signal superimposed on the control signal of the electromagnetic proportional valve 13.

  The dither setting unit 115 sets the condition of the dither signal to be superimposed on the control signal of the electromagnetic proportional valve 13. The dither setting unit 115 sets the amplitude Ad and the frequency Fd of the dither signal as the dither signal conditions. In the present embodiment, the dither setting unit 115 sets the condition of the dither signal based on at least the information of the hydraulic amplitude value Ap_act calculated by the hydraulic amplitude calculation unit 113. The dither setting unit 115 may further set the condition of the dither signal based on the information on the shift state of the CVT. The dither setting unit 115 may further set the condition of the dither signal based on information on at least one of the required current value I_tgt of the electromagnetic proportional valve 13 and the target hydraulic pressure P_tgt of the hydraulic chamber 11. In addition, the dither setting unit 115 may set the condition of the dither signal based on the information on the temperature (oil temperature) To of the hydraulic oil that can be detected at any position of the hydraulic system 10.

  The electromagnetic proportional valve control unit 117 calculates a required current value I_tgt of the electromagnetic proportional valve 13, generates a drive command signal based on the required current value I_tgt, and outputs it to the electromagnetic proportional valve drive unit 135. For example, the electromagnetic proportional valve control unit 117 outputs a drive command signal to the electromagnetic proportional valve drive unit 135 so that the electromagnetic proportional valve 13 outputs a control signal based on the required current value I_tgt and the hydraulic pressure change rate command value Rp_cmd. At this time, the electromagnetic proportional valve control unit 117 outputs a drive command signal so that a dither signal is superimposed on the control signal and output. The electromagnetic proportional valve drive unit 135 energizes the electromagnetic coil (actuator) of the electromagnetic proportional valve 13 according to the input control signal, and drives the electromagnetic proportional valve 13.

  The failure diagnosis unit 119 performs failure diagnosis of the hydraulic system 10 by comparing the dither setting value D_set calculated by the dither setting unit 115 with a dither reference model created in advance. The dither reference model is a model of a dither signal condition that can be set according to, for example, the oil temperature To, the required current value I_tgt, the target oil pressure P_tgt, and the oil pressure change rate command value Rp_cmd. The oil temperature To, the required current value I_tgt, the target oil pressure It can be expressed as a function f of P_tgt and hydraulic pressure change rate command value Rp_cmd. The amplitude model value Ad_mdl of the dither signal can be expressed by the following equation (1), for example.

… （１）
ｔ：油温Ｔｏ
ｉ：要求電流値Ｔ＿ｔｇｔ
ｐ：目標油圧Ｐ＿ｔｇｔ
ｒ：油圧変化率指令値Ｒｐ＿ｃｍｄ
ｃ：係数

(1)
t: Oil temperature To
i: Required current value T_tgt
p: target hydraulic pressure P_tgt
r: Oil pressure change rate command value Rp_cmd
c: Coefficient

  Further, the frequency model value Fd_mdl of the dither signal can be expressed by the following equation (2), for example.

… （２）
ｔ：油温Ｔｏ
ｉ：要求電流値Ｔ＿ｔｇｔ
ｐ：目標油圧Ｐ＿ｔｇｔ
ｒ：油圧変化率指令値Ｒｐ＿ｃｍｄ
ｃ：係数

(2)
t: Oil temperature To
i: Required current value T_tgt
p: target hydraulic pressure P_tgt
r: Oil pressure change rate command value Rp_cmd
c: Coefficient

  Therefore, in the examples of the above formulas (1) and (2), it is assumed under the current state of the hydraulic system 10 based on the information of the oil temperature To, the required current value I_tgt, the target hydraulic pressure P_tgt, and the hydraulic pressure change rate command value Rp_cmd. The model value of the amplitude Ad and the frequency Fd of the dither signal to be performed is calculated. The failure diagnosis unit 119 has a failure in the hydraulic system 10 when the amplitude Ad_fin and the frequency Fd_fin of the dither setting value D_set calculated by the dither setting unit 115 greatly deviate from the amplitude model value Ad_mdl and the frequency model value Fd_mdl. Is determined.

<3. Processing operation of control device (fault diagnosis device)>
Next, the processing operation by each part of the control device 100 for an electromagnetic proportional valve according to the present embodiment will be specifically described.

(3-1. Electromagnetic proportional valve drive control processing)
FIG. 3 is a flowchart showing an example of the drive control process of the electromagnetic proportional valve 13. First, the electromagnetic proportional valve control unit 117 of the control device 100 calculates a required current value I_tgt of the electromagnetic proportional valve 13 (step S11). For example, the electromagnetic proportional valve control unit 117 calculates the required current value I_tgt of the electromagnetic proportional valve 13 based on information such as the current gear ratio, the target value of the gear ratio, and the detected control oil pressure P_det.

  Next, the dither setting unit 115 of the control device 100 sets the condition of the dither signal added to the control signal of the electromagnetic proportional valve 13 (step S13). In the present embodiment, the dither setting unit 115 sets the condition of the dither signal based on at least information on the amplitude (hydraulic amplitude value) Ap_act of the control hydraulic pressure P_det. A specific dither signal condition setting process will be described later.

  Next, the electromagnetic proportional valve control unit 117 outputs a drive command signal to the electromagnetic proportional valve drive unit 135 based on the required current value I_tgt and the condition of the dither signal (step S15). The electromagnetic proportional valve control unit 117 outputs a drive command signal to superimpose a dither signal corresponding to the dither signal condition on the electromagnetic proportional valve drive unit 135 so as to output a control signal. The control device 100 repeatedly executes the drive control of the electromagnetic proportional valve 13 with the above steps S11 to S15 as one cycle.

(3-2. Dither signal condition setting process)
(3-2-1. Outline)
FIG. 4 is a schematic diagram showing an outline of processing for setting the conditions of the dither signal according to the present embodiment. In the example illustrated in FIG. 4, the first dither correction, the second dither correction, the third dither correction, and the addition for the reference value (hereinafter also referred to as “dither reference value”) D_bs of the condition of the dither signal. Dither correction is performed, and a setting value (hereinafter also referred to as “dither setting value”) D_set of the condition of the dither signal is obtained. In the present embodiment, the first dither correction performed based on the amplitude (hydraulic amplitude value) Ap_act of the control hydraulic pressure P_det detected by the pressure sensor 25 is essential, while the second dither correction and the third dither are performed. Correction and additional dither correction may be omitted.

  In the first dither correction, the dither reference value D_bs is corrected or updated by feeding back the hydraulic pressure amplitude Ap_act. For example, the dither reference value D_bs is corrected based on the difference ΔAp between the hydraulic pressure amplitude value Ap_act and the required pressure amplitude value Ap_tgt. In the second dither correction, the dither reference value D_bs is corrected or updated based on information on the operating state of the CVT. In the third dither correction, the dither reference value D_bs is corrected or updated based on information on at least one of the required current value I_tgt and the target hydraulic pressure P_tgt of the electromagnetic proportional valve 13. In the additional dither correction, the dither reference value D_bs is corrected or updated based on further information such as the oil temperature To.

  Here, the dither reference value D_bs includes a value of the amplitude Ad and the frequency Fd of the dither signal. The operating state of the CVT may include at least one of information on an operation request command value, for example, information such as a shift speed command value V_cmd, a hydraulic pressure change rate command value Rp_cmd, and a target hydraulic pressure P_tgt. The corrected dither setting value D_set includes the values of the amplitude Ad_fin and the frequency Fd_fin of the dither signal. When the dither setting value D_set obtained by correcting the dither reference value D_bs is obtained, the dither signal is superimposed on the control signal in accordance with the dither setting value D_set, and drive control of the electromagnetic proportional valve 13 is performed. Thereby, the pilot pressure of the pressure control valve 17 is controlled, and the control hydraulic pressure P_det supplied to the hydraulic chamber 11 is controlled. This control oil pressure P_det is fed back again and used to correct the dither reference value D_bs.

  In the first dither correction, the dither setting unit 115 corrects the dither reference value D_bs so that, for example, the hydraulic pressure amplitude value Ap_act converges to the required pressure amplitude value Ap_tgt. The dither reference value D_bs is a value set based on the operating state of the CVT. The required pressure amplitude value Ap_tgt is an optimum value for CVT control, which is determined in advance by experiment or simulation. FIG. 5 is an explanatory diagram showing the relationship between the value of the difference ΔAp (= Ap_act−Ap_tgt) between the hydraulic pressure amplitude value Ap_act and the required pressure amplitude value Ap_tgt and the degree of increase / decrease in the hysteresis reduction effect (dither effect) by correcting the dither signal. is there. The dither reference value D_bs is corrected so that the dither effect increases as the hydraulic pressure amplitude Ap_act is smaller than the required pressure amplitude value Ap_tgt (ΔAp <0). In addition, the dither reference value D_bs is corrected so that the dither effect decreases as the hydraulic pressure amplitude Ap_act is larger than the required pressure amplitude value Ap_tgt. For example, the dither setting unit 115 refers to a correction map stored in advance in the storage unit 130 and obtains a correction amount for the dither signal condition according to the difference ΔAp (hereinafter also referred to as “first dither correction amount”). Also good.

  In the second dither correction, the dither setting unit 115 may set a dither correction amount (hereinafter, also referred to as “second dither correction amount”) according to the CVT shift state and correct the dither reference value D_bs, for example. Good. The shift state of CVT may be, for example, information on at least one of acceleration command value Acc_cmd, shift speed command value V_cmd, and hydraulic pressure change rate command value Rp_cmd of a vehicle equipped with CVT. FIG. 6 is an explanatory diagram showing the relationship between the acceleration command value Acc_cmd and the control pressure hysteresis. The control pressure hysteresis increases as the acceleration command value Acc_cmd increases. Therefore, the dither reference value D_bs is corrected so that the dither effect increases as the acceleration command value Acc_cmd increases. The relationship between the shift speed command value V_cmd or the hydraulic pressure change rate command value Rp_cmd and the control pressure hysteresis is the same as the relationship between the acceleration command value Acc_cmd and the control pressure hysteresis. For example, the dither setting unit 115 may obtain a dither correction amount corresponding to information on each shift state with reference to a correction map stored in the storage unit 130 in advance.

  In the third dither correction, the dither setting unit 115, for example, a dither correction amount (hereinafter referred to as “third dither correction amount”) corresponding to at least one of the required current value I_tgt of the electromagnetic proportional valve 13 and the target hydraulic pressure P_tgt. Dither reference value D_bs may be corrected by setting. FIG. 7 is an explanatory diagram showing the relationship between the current value of the electromagnetic proportional valve 13 and the electromagnetic force hysteresis. As the current value increases, the electromagnetic force hysteresis increases. Therefore, the dither reference value D_bs is corrected so that the dither effect increases as the required current value I_tgt increases. For example, the dither setting unit 115 may obtain a dither correction amount corresponding to the required current value I_tgt with reference to a correction map stored in the storage unit 130 in advance. FIG. 8 is an explanatory diagram showing the relationship between the control oil pressure P_det and the control oil pressure hysteresis. As the control oil pressure P_det increases, the control oil pressure hysteresis increases. Therefore, the dither reference value D_bs is corrected so that the dither effect increases as the target hydraulic pressure P_tgt increases. For example, the dither setting unit 115 may obtain a dither correction amount corresponding to the target hydraulic pressure P_tgt with reference to a correction map stored in the storage unit 130 in advance.

  In the fourth dither correction, the dither setting unit 115 may correct the dither reference value D_bs by setting a dither correction amount (additional dither correction amount) according to the oil temperature To and other information, for example. When the dither reference value D_bs is corrected based on the oil temperature To, the lower the oil temperature To, the greater the viscosity of the hydraulic oil and the more likely the control oil pressure hysteresis occurs. Therefore, the lower the oil temperature To, the greater the dither effect. The dither reference value D_bs is corrected.

  The first to third dither correction amounts and the additional dither correction amount include a correction amount of at least one of the amplitude Ad and the frequency Fd of the dither signal. The dither setting unit 115 increases the dither signal amplitude Ad and / or decreases the frequency Fd, thereby increasing the dither effect. The dither setting unit 115 reduces the dither effect by reducing the amplitude Ad of the dither signal and / or increasing the frequency Fd.

  FIG. 4 also shows that the diagnosis of the hydraulic system 10 is performed based on the amplitude value (hydraulic amplitude value) Ap_act of the control hydraulic pressure P_det. The failure diagnosis process will be described later.

(3-2-2. Flowchart)
FIG. 9 is a flowchart showing an example of the dither signal condition setting process. This flowchart is a specific example of the flowchart of the process executed in step S13 of the flowchart shown in FIG.

  First, the dither setting unit 115 of the control device 100 sets the dither reference value D_bs based on the operating state of the CVT (step S21). The dither setting unit 115 may set the dither reference value D_bs based on at least one information of CVT operation state information such as a shift speed command value V_cmd, a hydraulic pressure change rate command value Rp_cmd, and a target hydraulic pressure P_tgt. . For example, the dither setting unit 115 may obtain the dither reference value D_bs based on the operating state of the CVT with reference to a dither reference map stored in the storage unit 130 in advance.

  Next, the dither setting unit 115 sets a first dither correction amount based on the hydraulic amplitude value Ap_act (step S23). FIG. 10 is a flowchart showing an example of the first dither correction amount setting process. In the example of the flowchart shown in FIG. 10, first, the hydraulic amplitude calculation unit 113 calculates the hydraulic amplitude value Ap_act based on the information of the control hydraulic pressure P_det acquired by the acquisition unit 111 (step S31). For example, the hydraulic pressure amplitude calculation unit 113 may have a maximum value and a minimum value of the control hydraulic pressure P_det in each period in which the change rate of the control hydraulic pressure P_det acquired at a predetermined time interval changes in a positive value or in a negative value. The value of the difference from the value may be the hydraulic pressure value Ap_act. However, the calculation method of the hydraulic pressure amplitude Ap_act is not limited to this example.

  Next, the dither setting unit 115 compares the calculated hydraulic amplitude value Ap_act with the required pressure amplitude value Ap_tgt (step S33). For example, the dither setting unit 115 obtains a difference ΔAp obtained by subtracting the required pressure amplitude value Ap_tgt from the hydraulic pressure amplitude value Ap_act. The required pressure amplitude value Ap_tgt is a reference value of the hydraulic amplitude Ap corresponding to each dither reference value D_bs, and the dither setting unit 115 refers to the required hydraulic amplitude map stored in the storage unit 130 in advance to obtain the dither reference value D_bs. A corresponding required pressure amplitude value Ap_tgt may be obtained.

  Next, the dither setting unit 115 calculates a first dither correction amount based on the comparison result between the hydraulic pressure amplitude value Ap_act and the required pressure amplitude value Ap_tgt (step S35). For example, the dither setting unit 115 sets the first dither correction amount so that the hydraulic amplitude value Ap_act converges to the required pressure amplitude value Ap_tgt. In the present embodiment, the dither setting unit 115 sets the first dither correction amount so that the dither effect increases as the value of the difference ΔAp decreases, and the first dither effect decreases so that the dither effect decreases as the value of the difference ΔAp increases. Set the dither correction amount. For example, the dither setting unit 115 may obtain a first dither correction amount corresponding to the difference ΔAp with reference to a correction map stored in the storage unit 130 in advance.

  For example, it is known that when the sliding resistance of the electromagnetic proportional valve 13 or the pressure control valve 17 increases due to a foreign matter biting in, the control hydraulic hysteresis increases. In such a case, the piston 15 of the electromagnetic proportional valve 13 is increased. The hydraulic pressure amplitude value Ap_act becomes smaller than the required pressure amplitude value Ap_tgt. The dither setting unit 115 sets the first dither correction amount so that the dither effect is increased in such a case. On the other hand, when the hydraulic pressure amplitude value Ap_act is larger than the required pressure amplitude value Ap_tgt and the control hydraulic pressure P_det becomes unstable, the first dither correction amount is set so that the dither effect is reduced.

  Returning to FIG. 9, the dither setting unit 115 then sets the second dither correction amount based on the information on the shift state of the CVT (step S24). FIG. 11 is a flowchart illustrating an example of a second dither correction amount setting process based on information on the shift state of the CVT. In the example of the flowchart shown in FIG. 11, first, the acquisition unit 111 acquires CVT shift state information (step S <b> 41). The acquisition unit 111 acquires, for example, at least one information of an acceleration command value Acc_cmd, a shift speed command value V_cmd, and a hydraulic pressure change rate command value Rp_cmd of a vehicle equipped with the CVT as information on the shift state of the CVT.

  Next, the dither setting unit 115 calculates a second dither correction amount based on the acquired information on the shift state (step S43). For example, the dither setting unit 115 sets the second dither correction amount so that the dither effect increases as the acceleration command value Acc_cmd increases. Similarly, the dither setting unit 115 sets the second dither correction amount so that the dither effect increases as the shift speed command value V_cmd or the hydraulic pressure change rate command value Rp_cmd increases. For example, the dither setting unit 115 may obtain a second dither correction amount corresponding to information on each shift state with reference to a correction map stored in the storage unit 130 in advance.

  Returning to FIG. 9, the dither setting unit 115 then sets the third dither correction amount based on at least one of the required current value I_tgt and the target hydraulic pressure P_tgt of the electromagnetic proportional valve 13 (step S25). FIG. 12 is a flowchart showing an example of a third dither correction amount setting process based on information on the required current value I_tgt and the target hydraulic pressure P_tgt of the electromagnetic proportional valve 13. In the example of the flowchart shown in FIG. 12, the acquisition unit 111 first acquires information on the required current value I_tgt and the target hydraulic pressure P_tgt (step S51). Next, the dither setting unit 115 sets a third dither correction amount based on the information on the required current value I_tgt and the target hydraulic pressure P_tgt (step S53). For example, the dither setting unit 115 sets the third dither correction amount so that the dither effect increases as the required current value I_tgt increases. The dither setting unit 115 sets the third dither correction amount so that the dither effect increases as the target hydraulic pressure P_tgt increases. For example, the dither setting unit 115 may obtain the third dither correction amount by referring to the required current correction map and the target hydraulic pressure correction map stored in the storage unit 130 in advance.

  The dither setting unit 115 does not set the third dither correction amount based on the information of the required current value I_tgt and the target hydraulic pressure P_tgt, but instead of setting the third dither correction amount based on only the information on either the required current value I_tgt or the target hydraulic pressure P_tgt. A dither correction amount of 3 may be set.

  Returning to FIG. 9, the dither setting unit 115 then sets an additional dither correction amount based on further information (step S26). Further information includes, for example, information on the oil temperature To, information on the line pressure supplied to the electromagnetic proportional valve 13 and the pressure control valve 17, information on the temperature of the electromagnetic proportional valve 13, and information on the atmospheric temperature of the hydraulic system 10, etc. At least one piece of information may be included. The additional dither correction amount based on these pieces of information may be set in advance according to the control hydraulic hysteresis or electromagnetic force hysteresis obtained by experiments, simulations, or the like, and stored in the storage unit 130 as a correction map. The dither setting unit 115 may obtain the additional dither correction amount with reference to the correction map stored in the storage unit 130.

  Returning to FIG. 9, the dither setting unit 115 calculates the dither setting value D_set by adding or subtracting the first to third dither correction amounts and the additional dither correction amount with respect to the dither reference value D_bs (step S28). ). For example, the dither setting unit 115 adds or subtracts the amplitude Ad and the frequency Fd of the dither reference value D_bs according to the amplitude and frequency correction amounts included in the first to third dither correction amounts and the additional dither correction amount. The amplitude Ad_fin and the frequency Fd_fin of the dither setting value D_set are set. The dither signal corresponding to the dither setting value D_set thus set is superimposed on the control signal, and drive control of the electromagnetic proportional valve 13 is performed.

(3-3. Fault diagnosis processing)
Next, an example of failure diagnosis processing of the hydraulic system 10 executed by the failure diagnosis unit 119 of the control device 100 will be described.

  FIG. 13 is a flowchart illustrating an example of a failure diagnosis process of the hydraulic system 10. In the example of the failure diagnosis process of this embodiment, the failure diagnosis unit 119 performs failure diagnosis of the hydraulic system 10 by comparing the dither setting value D_set set by the dither setting unit 115 with a preset dither reference model.

  First, the failure diagnosis unit 119 of the control device 100 acquires information on the dither setting value D_set calculated by the dither setting unit 115 (step S71). The dither set value D_set is a set value of the condition of the dither signal corrected based on at least the amplitude value (hydraulic amplitude value) Ap_act of the control oil pressure P_det. In the present embodiment, the failure diagnosis unit 119 may acquire the value of the amplitude Ad and the frequency Fd of the dither signal as the dither setting value D_set.

  Next, the failure diagnosis unit 119 uses the above formulas (1) and (2) based on the information on the oil temperature To, the required current value T_tgt, the target oil pressure P_tgt, and the oil pressure change rate command value Rp_cmd to dither the current CVT in the operating state. A signal amplitude model value Ad_mdl and a frequency model value are calculated (step S73).

  Next, the failure diagnosis unit 119 compares the amplitude Ad and frequency Fd values of the dither setting value D_set with the amplitude model value Ad_mdl and frequency model value Fd_mdl (step S75). In this embodiment, the failure diagnosis unit 119 obtains a difference ΔAd between the amplitude Ad of the dither setting value D_set and the amplitude model value Ad_ml, and obtains a difference ΔFd between the frequency Fd of the dither setting value D_set and the frequency model value Fd_mdl.

  Next, the failure diagnosis unit 119 determines whether or not the deviation between the amplitude Ad of the dither setting value D_set and the amplitude model value Ad_mdl and the deviation between the frequency Fd of the dither setting value D_set and the frequency model value Fd_mdl are within an allowable range. (Step S77). In the present embodiment, it is determined whether or not the differences ΔAd and ΔFd obtained in step S75 are less than or equal to preset threshold values ΔAd_0 and ΔFd_0, respectively.

  When the differences ΔAd and ΔFd are both equal to or smaller than the threshold values ΔAd_0 and ΔFd_0 (S77 / Yes), the failure diagnosis unit 119 determines that no failure has occurred in the hydraulic system 10 (step S79), and ends the failure diagnosis processing. On the other hand, when the difference ΔAd exceeds the threshold value ΔAd_0 or the difference ΔFd exceeds the threshold value ΔFd_0 (S77 / No), the failure diagnosis unit 119 determines that a failure has occurred in the hydraulic system 10 (step S81). Further, the failure diagnosis unit 119 stops the dither signal condition correction processing executed by the dither setting unit 115 (step S83), and ends the failure diagnosis processing. Either step S81 or step S83 may be omitted. Further, the failure diagnosis unit 119 may execute a process of notifying the driver of the failure, such as turning on a warning lamp.

(3-4. Reference example of failure diagnosis processing)
FIG. 14 is a flowchart showing a reference example of failure diagnosis processing of the hydraulic system 10. In the reference example, the failure diagnosing unit 119 compares the difference ΔAp between the hydraulic pressure amplitude value P_det calculated by the hydraulic pressure amplitude calculating unit 113 and the required pressure amplitude value Ap_tgt with a preset threshold value ΔAp_0 to diagnose the failure of the hydraulic system 10. Do.

  First, the failure diagnosis unit 119 of the control device 100 acquires information on the difference ΔAp between the hydraulic pressure amplitude value Ap_act and the required pressure amplitude value Ap_tgt (step S61). In the present embodiment, the failure diagnosis unit 119 acquires information on the difference ΔAp calculated by the dither setting unit 115. However, there is no particular limitation on how to acquire information on the difference ΔAp, such as the failure diagnosis unit 119 calculating the difference ΔAp.

  Next, the failure diagnosis unit 119 determines whether or not the difference ΔAp is greater than or equal to a preset threshold value ΔAp_0 (step S63). The threshold value ΔAp_0 is a value set by an experiment or simulation performed on the hydraulic system 10, and is set to an appropriate value that can determine that the hydraulic pressure amplitude value Ap_act exceeds the required pressure amplitude value Ap_tgt. Is done. The threshold value ΔAp_0 may be a variable value that can change according to the oil temperature To. In this case, the threshold value may be set so as to increase as the oil temperature To decreases.

  When the difference ΔAp is equal to or greater than the threshold value ΔAp_0 (S63 / Yes), the failure diagnosis unit 119 determines that a failure has occurred in the hydraulic system 10 (step S65), and ends the failure diagnosis process. In this case, the failure diagnosis unit 119 may stop the dither signal condition correction by the dither setting unit 115. Further, the failure diagnosis unit 119 may execute a process of notifying the driver of the failure, such as turning on a warning lamp. On the other hand, when the difference ΔAp is less than the threshold value ΔAp_0 (S63 / No), the failure diagnosis unit 119 determines that no failure has occurred in the hydraulic system 10 (step S67), and ends the failure diagnosis process.

<4. Effect>
As described above, the hydraulic system failure diagnosis apparatus (control apparatus) 100 according to the present embodiment determines the dither signal conditions set in advance by feeding back the amplitude value (hydraulic amplitude value) Ap_act of the control hydraulic pressure P_det. 10 fault diagnosis of the hydraulic system is performed by comparing with the value of the created dither reference model. For this reason, failure diagnosis of the hydraulic system 10 can be appropriately executed in consideration of changes in conditions due to changes in the surrounding environment. Therefore, when the CVT operation is not normally performed due to the failure of the hydraulic system 10, the abnormal operation of the CVT can be eliminated by replacing the components of the hydraulic system 10 instead of the entire CVT system.

  Further, the failure diagnosis apparatus 100 according to the present embodiment uses a dither reference model in which at least one of the required current value I_tgt, the target hydraulic pressure P_tgt, the oil temperature To, and the change rate Rp of the control hydraulic pressure of the electromagnetic proportional valve 13 is a variable. ing. For this reason, it is possible to improve the accuracy of failure diagnosis in consideration of changes in conditions due to changes in the surrounding environment.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Hydraulic system 11 Hydraulic chamber 13 Electromagnetic proportional valve 17 Pressure control valve 25 Pressure sensor 100 Control apparatus (failure diagnosis apparatus)
DESCRIPTION OF SYMBOLS 110 Control part 111 Acquisition part 113 Hydraulic amplitude calculation part 115 Dither setting part 117 Electromagnetic proportional valve control part 119 Failure diagnosis part

Claims (5)

In the fault diagnosis device (100) of the hydraulic system (10) including the electromagnetic proportional valves (13P, 13S) for adjusting the control hydraulic pressure supplied to the hydraulic chambers (11P, 11S) of the pulleys of the continuously variable transmission,
Obtaining information on the condition of the dither signal to be superimposed on the control signal of the electromagnetic proportional valve (13P, 13S) set based on the amplitude information of the control oil pressure;
A failure diagnosis apparatus for a hydraulic system, comprising: a failure diagnosis unit (119) that performs failure diagnosis of the hydraulic system by comparing the condition of the dither signal with a dither reference model created in advance. The dither reference model uses at least one of a required current value of the electromagnetic proportional valves (13S, 13P), a target pressure of the hydraulic oil, an oil temperature of the hydraulic oil, and a change rate of the control hydraulic pressure as a variable. The fault diagnosis apparatus for a hydraulic system according to claim 1, which is a model. The hydraulic system according to claim 1 or 2, wherein the failure diagnosis unit (119) determines that there is a failure in the hydraulic system (10) when a difference between a condition of the dither signal and the dither reference model exceeds a threshold value. Fault diagnosis device. The failure diagnosis unit (119) stops the setting of the dither signal based on the amplitude information of the control hydraulic pressure when a difference between the dither signal condition and the dither reference model exceeds a threshold value. The failure diagnosis apparatus for a hydraulic system according to any one of the above. In a failure diagnosis method for a hydraulic system (10) including an electromagnetic proportional valve (13P, 13S) for adjusting a control hydraulic pressure supplied to a hydraulic chamber (11P, 11S) of a pulley of a continuously variable transmission,
Obtaining information on the condition of the dither signal to be superimposed on the control signal of the electromagnetic proportional valve (13P, 13S) set based on the information on the amplitude of the control hydraulic pressure (S71);
A hydraulic system failure diagnosis method comprising: (S77) performing a failure diagnosis of the hydraulic system by comparing a condition of the dither signal with a dither reference model created in advance.

Images