JP2018013209A - Electric oil pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric oil pump device capable of rapidly securing a hydraulic pressure and a discharge oil amount according to an oil temperature condition by improving responsiveness of output control of a motor.SOLUTION: An electric oil pump device 100 comprises: an electric oil pump 10 including a motor 11 and driven by the motor 11; and a micro computer 30 for estimating an oil temperature TE on the basis of the relation between at least one of the hydraulic pressure, the motor current value Im and the torque of the electric oil pump 10, which are detected during operation of the electric oil pump 10, and at least one of the discharge oil amount and the motor rotation speed N of the electric oil pump 10, and for adjusting the control parameters (proportional gain Kp, integral gain Ki, differential gain Kd) of the feedback control related to the motor current value Im or the motor rotation speed N on the basis of the estimated oil temperature TE.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an electric oil pump device, and more particularly to an electric oil pump device including an electric oil pump driven by a motor.

  Conventionally, an electric oil pump device including an electric oil pump driven by a motor is known (see, for example, Patent Document 1).

  Patent Document 1 discloses an electric liquid pump control device (electric oil pump device) including a hydraulic pump (electric oil pump) driven by a motor and a microcomputer (control unit) that performs rotation control of the electric motor. It is disclosed. In the control device for the electric liquid pump described in Patent Document 1, the electric pump is discharged from the hydraulic pump based on the relationship between the motor current value detected from the motor rotated by the electric power input as a certain initial value and the rotational speed. It is comprised so that oil temperature may be estimated. Then, in order to obtain the hydraulic pressure required for the hydraulic pump under the estimated oil temperature condition, current control for calculating the target value of the current supplied to the motor and shifting the motor current value to the target value is performed. Done. In this case, the microcomputer calculates a command voltage (duty ratio) to be applied to the motor by proportional control and integral control (PI control) based on the deviation between the target value of the motor current value and the current value. Then, the motor current value during rotation is changed with the control of the command voltage, and the target value is reached. Therefore, the hydraulic pressure required for the hydraulic circuit is ensured by the output control of the motor according to the change in the oil temperature.

  The above-described electric liquid pump (electric oil pump) is activated (driven) when the idling of the engine is stopped when the automobile is stopped, for example. Thereby, the hydraulic pressure is supplied to the clutch engagement of the automatic transmission even in the idling stop state. The electric liquid pump is also activated (driven) when cooling oil is supplied to the cooling jacket of the electric motor of the hybrid vehicle. As a result, cooling oil having a predetermined hydraulic pressure is circulated through the cooling jacket.

Japanese Patent Laid-Open No. 2005-16460

  In the control device for the electric liquid pump described in Patent Document 1, a command to be applied to the motor simply using proportional control and integral control (PI control) based on the deviation between the target value of the motor current value and the current value. It is considered that a control method (so-called general feedback control) for calculating a voltage (duty ratio) is applied. For this reason, it is considered that a certain amount of time is required for the transition from the current value (initial value) of the motor current value to the target value. However, as described above, when the electric liquid pump (electric oil pump) is applied to the hydraulic control of the automobile, it is necessary to ensure a quick hydraulic pressure and discharge oil amount according to the oil temperature condition (oil viscosity condition). . For this reason, in the drive control of the electric oil pump, high responsiveness is required for the output control of the motor.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to improve the responsiveness of the output control of the motor so that the hydraulic pressure and the discharge according to the oil temperature condition are improved. It is an object of the present invention to provide an electric oil pump device capable of quickly securing an oil amount.

  In order to achieve the above object, an electric oil pump device according to one aspect of the present invention includes a motor, an electric oil pump driven by the motor, and an oil pressure of the electric oil pump detected during operation of the electric oil pump. The oil temperature is estimated based on the relationship between at least one of the motor current value or torque and at least one of the discharge oil amount of the electric oil pump or the motor rotation speed, and based on the estimated oil temperature A control unit that adjusts a control parameter for feedback control related to the motor current value or the motor rotation speed.

  As described above, the electric oil pump device according to one aspect of the present invention includes at least one of the hydraulic pressure, the motor current value, and the torque of the electric oil pump detected during the operation of the electric oil pump, and the electric oil pump. Control that estimates the oil temperature based on the relationship with at least one of the amount of discharged oil and the motor rotation speed, and adjusts the control parameter for feedback control related to the motor current value or the motor rotation speed based on the estimated oil temperature A part. As a result, the output control (motor current control) of the electric oil pump can be performed while adjusting the control parameter of the feedback control related to the motor current value or the motor rotation speed based on the estimated oil temperature. Unlike general feedback control without adjustment, the current motor current value can be quickly brought close to the target current value. As a result, by improving the responsiveness of the motor output control, it is possible to quickly ensure the hydraulic pressure and the amount of discharged oil according to the oil temperature condition.

  In addition, since the electric oil pump device according to the one aspect includes the control unit described above, even when the oil viscosity varies according to the oil temperature (the load of the electric oil pump varies), the output control of the motor can be performed. Since responsiveness can be improved, the range of oil temperature (oil viscosity) in which this electric oil pump can be used can be expanded. In addition, even when the design tolerances of the pump unit and the motor constituting the electric oil pump are alleviated (design accuracy is reduced), the output adjustment of the electric oil pump (motor current control) can be performed quickly. Therefore, it is possible to easily perform accuracy control in designing and manufacturing the electric oil pump.

  In the electric oil pump device according to the above aspect, the control unit preferably determines an excess / deficiency state regarding at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump based on the estimated oil temperature, and an excess / deficiency state. The control parameter of the feedback control related to the motor current value or the motor rotation speed is adjusted so as to avoid the problem.

  If comprised in this way, since the fluctuation | variation of the load (at least one of hydraulic pressure or discharge oil amount) of an electric oil pump is grasped | ascertained according to the estimated oil temperature (oil viscosity), the fluctuation | variation of oil temperature (oil viscosity) At the same time, even if the load of the electric oil pump fluctuates and the possibility of falling into an excess or deficiency state related to at least one of the hydraulic pressure or the amount of discharged oil increases, the control parameter for feedback control related to the motor current value or motor speed is adjusted Thus, it is possible to reliably avoid falling into this excess / deficiency state. As a result, even if the load of the electric oil pump fluctuates due to fluctuations in the oil temperature (oil viscosity), the electric oil pump is operated stably and the hydraulic pressure and discharge oil amount according to the oil temperature conditions Can be ensured.

  In this case, preferably, the excess / deficiency state is a shortage state of at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump when the estimated oil temperature is lower than the first threshold value, and the estimated oil temperature is And an excess state of at least one of the hydraulic oil pressure and the discharge oil amount of the electric oil pump in the case where it is larger than the second threshold value, and the control unit is based on the estimated oil temperature and is at least one of the insufficiency state or the excess state It is configured to adjust the control parameter so as to avoid the problem.

  With this configuration, it is possible to easily estimate the load state of the electric oil pump based on whether the estimated oil temperature (oil viscosity) is less than the first threshold value or greater than the second threshold value. it can. Then, by adjusting the control parameter of the feedback control related to the motor current value or the motor speed according to the estimated load state (insufficient state or excessive state), at least one of the output shortage state or the overpower state of the electric oil pump is determined. It can be avoided quickly. That is, it is possible to avoid insufficient lubrication of oil in the lubrication system due to an insufficient output state, insufficient hydraulic pressure of the automatic transmission, and insufficient cooling of the cooling jacket due to oil. Further, it is possible to avoid the occurrence of power loss (energy loss) in the electric oil pump due to the overpower state.

  In the electric oil pump device according to the one aspect, preferably, the electric oil pump device further includes a table in which the estimated value of the oil temperature during the operation of the electric oil pump is associated with the control parameter, and the control unit is based on the table. , Configured to adjust control parameters.

  If comprised in this way, with reference to the said table | surface with which the estimated value of the oil temperature during operation | movement of an electric oil pump and a control parameter were each matched, the output control (motor of motor oil pump by adjustment of a control parameter will be carried out. Current control) can be easily performed.

  In the electric oil pump device according to the above aspect, the control unit preferably controls the control parameter based on a correlation equation in which a correlation between the estimated value of the oil temperature and the control parameter during operation of the electric oil pump is defined. Configured to adjust.

  If comprised in this way, based on the correlation formula in which the correlation between the estimated value of the oil temperature during the operation of the electric oil pump and the control parameter was defined, the output control of the electric oil pump by adjusting the control parameter (electric Motor current control) can be easily performed.

  The following configuration is also conceivable in the electric oil pump device according to the above aspect.

(Additional item 1)
That is, in the electric oil pump device according to the above aspect, the control unit controls the motor by PID control including proportional control, integral control, and differential control, and as a control parameter, the proportional gain of proportional control, the integral of integral control The gain and the differential gain of the differential control are configured to be adjusted.

(Appendix 2)
In the electric oil pump device according to the first aspect, the control unit estimates the oil temperature at a predetermined control cycle and relates to the motor current value or the motor rotation speed based on the oil temperature estimated at the predetermined control cycle. The control parameter of the feedback control is configured to be adjusted repeatedly.

(Additional Item 3)
Further, in the electric oil pump device according to the above one aspect, the control unit estimates the oil temperature based on the motor current value and the motor rotation speed during at least one of the electric oil pump during steady operation or startup, and Based on the estimated oil temperature, a control parameter for feedback control related to the motor current value or the motor rotation speed is adjusted.

It is the block diagram which showed the structure of the electric oil pump apparatus by 1st Embodiment of this invention. It is the figure which showed the concept of PID control (feedback control) with respect to the electric oil pump by 1st Embodiment of this invention. It is the figure which showed the content of the table used for the output control of the electric oil pump by 1st Embodiment of this invention. It is the figure which showed the processing flow of the microcomputer in the output control of the electric oil pump by 1st Embodiment of this invention. It is a figure for demonstrating the equation of motion in the drive system (rotary motion system) of the electric oil pump by 2nd Embodiment of this invention, and its transfer function. It is the figure which showed the equivalent conversion table | surface of the block diagram in the feedback control system of the electric oil pump by 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
First, with reference to FIGS. 1-3, the structure of the electric oil pump apparatus 100 by 1st Embodiment of this invention is demonstrated.

  The electric oil pump device 100 according to the first embodiment of the present invention is mounted on a vehicle (automobile). The electric oil pump device 100 includes an electric oil pump 10, a motor drive circuit 20 for driving the electric oil pump 10, and a microcomputer 30 (an example of a control unit) for transmitting a drive signal to the motor drive circuit 20. With. The motor drive circuit 20 and the microcomputer 30 may be mounted in the housing of the electric oil pump 10 or may be provided in a control box (not shown) different from the electric oil pump 10. .

  The electric oil pump 10 includes a motor 11 and a pump unit 12. The electric oil pump 10 has a pump unit 12 connected to a hydraulic circuit 101. The hydraulic circuit 101 has a predetermined flow path resistance R, and the hydraulic pressure necessary for the hydraulic circuit 101 is supplied by driving the pump unit 12. Here, an internal gear type, an external gear type, a centrifugal type, or the like is applied to the pump unit 12. The hydraulic circuit 101 includes a circuit that supplies hydraulic oil necessary for clutch engagement of the automatic transmission when the engine (not shown) is idling stopped while the automobile is stopped. Further, the hydraulic circuit 101 includes a circuit that supplies cooling oil of a necessary hydraulic pressure to a cooling jacket of an electric motor (not shown) of the hybrid vehicle. Unlike the mechanical oil pump driven by the driving force of the engine, the electric oil pump 10 is frequently used as an oil pump driven by electric power supplied from the battery 40.

  The motor 11 in the electric oil pump 10 is a sensorless three-phase brushless DC motor that does not have a position detection sensor such as a hall element. The motor drive circuit 20 includes an FET circuit 21 made of a semiconductor switch and a motor drive IC 22. The DC voltage of the battery 40 is applied to the three wires (the U-phase drive coil, the V-phase drive coil, and the W-phase drive coil) of the motor 11 via the FET circuit 21. The FET circuit 21 sequentially applies a voltage between two of the three wires of the motor 11 (between the U phase and the V phase, between the U phase and the W phase, and between the V phase and the W phase) based on the signal from the motor driving IC 22. It plays the role of applying and rotating the motor 11 by unit rotation angle. At this time, the FET circuit 21 performs PWM control (duty ratio) that repeatedly switches between a state in which the voltage applied between the two wires is turned on for a predetermined time and a state in which the voltage is turned off for a predetermined time in accordance with a signal from the motor drive IC 22. Control). As a result, the average voltage applied to the motor 11 is controlled to become a control command voltage.

  The microcomputer 30 includes a calculation unit 31 (an example of a control unit) that performs various calculation processes, a ROM 32 that stores various programs executed by the calculation unit 31 in advance, and data that the calculation unit 31 reads and writes during the calculation process. The RAM 33 includes a unit angle rotation signal and a motor current signal, and an input / output circuit 34 that outputs a command voltage for driving the motor 11 to the motor drive IC 22.

  The ROM 32 estimates the oil temperature Te based on the motor rotational speed calculation program 1, the motor current value Im (corresponding to torque and hydraulic pressure), and the motor rotational speed N (corresponding to the discharge oil amount) of the motor 11, and pumps. Stored is a motor control program 2 for supplying necessary hydraulic oil from the section 12 to the hydraulic circuit 101. The ROM 32 calculates a difference (current deviation e (t)) between the motor current value Im detected by the current detection circuit 42 and the target current value Itg, and performs PID control including proportional control, integral control, and differential control. The current control program 3 that calculates the command voltage u (t) to be applied to the motor 11 using the, and outputs the command voltage u (t) to the motor drive IC 22 and the table 4 (see FIG. 3) that is referred to during the PID control are further stored. Yes. The microcomputer 30 is connected to the ECU 102 on the vehicle body side so as to be able to communicate with each other. Therefore, the microcomputer 30 is configured to operate (calculate) based on a control signal from the ECU 102.

  The electric oil pump device 100 includes a shunt resistor 41 and a current detection circuit 42 in the control circuit in addition to the motor drive circuit 20 and the microcomputer 30. The shunt resistor 41 is connected to the FET circuit 21, and the current detection circuit 42 measures a voltage between both terminals of the shunt resistor 41 to detect a current value supplied to the motor 11 to detect a motor current signal (motor The current value Im) is sent to the microcomputer 30.

(Details of electric oil pump output control)
During the operation of the electric oil pump 10, the motor 11 is driven based on PID control as shown in FIG. In other words, it is assumed that a command for rotating the motor 11 at a current value including the target current value Itg is transmitted from the ECU 102 (see FIG. 1) side under certain operating conditions. The target current value Itg means a current value for ensuring the hydraulic pressure and the discharge oil amount required for the current hydraulic circuit 101 (see FIG. 1) by rotating the motor 11 with this current value. . In this case, the microcomputer 30 (see FIG. 1) calculates a current deviation e (t) between the current motor current value Im detected by the current detection circuit 42 and the target current value Itg, and uses the motor current value Im as the target current. PID control as feedback control is executed so as to match the value Itg. Control parameters in PID control include proportional gain Kp (hereinafter referred to as Kp) for proportional control, integral gain Ki (hereinafter referred to as Ki) for integral control, and differential gain Kd (hereinafter referred to as Kd) for differential control. It is. Then, a command voltage u (t) based on the duty ratio generated by the PID control is applied to the motor 11.

  Note that the command voltage u (t) based on PID control is expressed by Expression (1) shown in the lower region of FIG. That is, the command voltage u (t) is the product of the proportional gain Kp and the current deviation e (t), the product of the integral gain Ki and the integration value of the current deviation e (t) from 0 to t, It is given as a value obtained by adding the product of the differential gain Kd and the differential value of the current deviation e (t).

  Here, the first embodiment is configured such that the adjustment control described below is added to the PID control applied to the electric oil pump 10 (motor 11) based on a command from the calculation unit 31 of the microcomputer 30. ing.

  Specifically, the oil temperature Te is estimated based on the relationship between the motor current value Im of the electric oil pump 10 detected during the operation of the electric oil pump 10 and the motor rotational speed N, and the estimated oil temperature The computing unit 31 is configured such that the PID control is performed by adjusting Kp, Ki, and Kd of the PID control relating to the motor current value Im or the motor rotational speed N internally (automatically) based on Te.

  The correlation between the estimated value of the oil temperature Te with respect to the motor current value Im (corresponding to torque and hydraulic pressure) and the motor rotational speed N (corresponding to the amount of discharged oil) is stored in advance in the ROM 32 (see FIG. 1) of the microcomputer 30. ing. In this case, data on the kinematic viscosity of the oil corresponding to the combination of the detected motor current value Im and the motor rotational speed N is stored in the ROM 32. The oil temperature Te is calculated (estimated) based on the kinematic viscosity of the oil acquired from the ROM 32 in accordance with the combination of the motor current value Im and the motor rotation speed N.

As a specific example, the relationship between the kinematic viscosity (oil viscosity) of hydrocarbon oil and the oil temperature is expressed by the following formula (2) widely used as “Walther's empirical formula”.
log (log (ν + k)) = n− (m × log (Te)) (2)
In the above formula (2), ν is the kinematic viscosity (mm ² / s) of the oil, k, m and n are constants determined by the type of oil, and Te is the oil temperature indicated by the absolute temperature (K). .

  Therefore, the oil temperature Te corresponding to an arbitrary kinematic viscosity ν (oil viscosity) can be calculated using the above formula (2). Thereby, the microcomputer 30 obtains the kinematic viscosity ν of the oil discharged from the pump unit 12 from the relationship between the motor current value Im detected during the operation of the electric oil pump 10 and the motor rotation speed N. The oil temperature Te corresponding to the obtained oil viscosity (kinematic viscosity ν) is estimated (calculated) using the above formula (2).

  As a result, the electric oil pump device 100 adjusts the feedback control Kp, Ki, and Kd related to the motor current value Im or the motor rotational speed N based on the estimated oil temperature Te (oil viscosity), while the electric oil pump 10 Output control (current control of the motor 11) is performed. As a result, the current motor current value Im can be quickly brought close to the target current value Itg.

  As shown in FIG. 1, the motor current value Im (see FIG. 2) is grasped on the microcomputer 30 side based on the voltage between both terminals of the shunt resistor 41 detected by the current detection circuit 42. The motor rotation speed N (see FIG. 2) is the induced voltage generated in each of the number of poles of the motor 11 and the three wires (U-phase drive coil, V-phase drive coil, and W-phase drive coil) of the rotating motor 11. On the microcomputer 30 side based on the count number of the zero-cross point (the phase at the time when the induced voltage waveform becomes half of its amplitude) in the waveform.

  In the first embodiment, the microcomputer 30 determines an excess / deficiency state related to at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump 10 based on the estimated oil temperature Te (oil viscosity), and an excess / deficiency state. Is configured to adjust the feedback control Kp, Ki, and Kd related to the motor current value Im or the motor rotational speed N.

  In this case, as the excess / deficiency state, the load (at least one of the hydraulic pressure and the discharge oil amount) of the electric oil pump 10 when the estimated oil temperature Te is lower than the threshold value T1 (an example of the first threshold value). Of the electric oil pump 10 when the estimated oil temperature Te is larger than the threshold value T2 (an example of the second threshold value). At least one of the “excessive state (overpower region)” exists. Based on the estimated oil temperature Te (oil viscosity), the microcomputer 30 is configured to adjust Kp, Ki, and Kd in the PID control so as to avoid at least one of an insufficiency state or an excess state. . In order to avoid the shortage state, Kp, Ki and Kd are increased. In order to avoid an excessive state, Kp, Ki and Kd are reduced.

  The ROM 32 (see FIG. 1) stores (saves) a table 4 as shown in FIG. In the table 4, the estimated oil temperature Te is associated with the control parameters (proportional gain Kp, integral gain Ki, and differential gain Kd) corresponding to each oil temperature Te. Therefore, the calculation unit 31 (see FIG. 1) is configured to adjust Kp, Ki, and Kd based on the table 4.

  The microcomputer 30 estimates the oil temperature Te based on the motor current value Im and the motor rotation speed N during the steady operation of the electric oil pump 10, and based on the estimated oil temperature Te, the motor current value Im or the motor It is configured to adjust Kp, Ki, and Kd of feedback control related to the rotational speed N. In this case, the microcomputer 30 estimates the oil temperature Te at a predetermined control cycle and, based on the oil temperature Te estimated at the predetermined control cycle, feedback control Kp, Ki for the motor current value Im or the motor rotation speed N. And Kd are repeatedly adjusted.

  Next, a processing flow of the microcomputer 30 (calculation unit 31) when the electric oil pump 10 is activated in the electric oil pump device 100 will be described with reference to FIGS.

  As shown in FIG. 4, in step S1, the current motor speed N of the motor 11 (see FIG. 1) is detected based on a command from the microcomputer 30 (see FIG. 1). The motor rotation speed N is the waveform of the induced voltage generated in each of the number of poles of the motor 11 and the three wires (the U-phase drive coil, the V-phase drive coil, and the W-phase drive coil) when the motor 11 starts to rotate. Is obtained based on the count number of zero cross points. In step S2, the current motor current value Im of the motor 11 is detected. The motor current value Im is acquired based on the voltage between both terminals of the shunt resistor 41 (see FIG. 1) detected by the current detection circuit 42.

  Thereafter, in step S3, the microcomputer 30 determines whether or not the electric oil pump 10 (motor 11) is in steady operation. If it is determined in step S3 that the vehicle is not in steady operation, the processing flow is temporarily terminated. After the end of this control flow, this control flow shown in FIG. 4 is executed again after a predetermined control cycle has elapsed.

  When it is determined in step S3 that the vehicle is in steady operation, the oil temperature Te of the electric oil pump 10 is acquired (estimated) by the microcomputer 30 in step S4. The oil temperature Te is calculated based on the relationship between the motor rotational speed N detected in step S1 and the motor current value Im detected in step S2, and the kinematic viscosity of oil obtained from the ROM 32 (Walther's empirical formula: 2)), the calculation unit 31 (see FIG. 1) calculates.

  Thereafter, in step S5, it is determined whether or not the oil temperature Te is lower than the threshold value T1. If it is determined in step S5 that the oil temperature Te is lower than the threshold value T1 (ie, it is determined that the load of the electric oil pump 10 is “insufficient (output shortage region)”), in step S6, the proportionality The control parameters of the feedback control are adjusted by the microcomputer 30 so as to increase the gain Kp, the integral gain Ki, and the differential gain Kd (see FIG. 2).

  When it is determined in step S5 that the oil temperature Te is equal to or higher than the threshold value T1, it is determined in step S7 whether or not the oil temperature Te is higher than the threshold value T2. If it is determined in step S7 that the oil temperature Te is greater than the threshold value T2 (ie, it is determined that the load of the electric oil pump 10 is in the “excess state (overpower region)”), in step S8, the proportional Each control parameter of the feedback control is adjusted by the microcomputer 30 so as to decrease the gain Kp, the integral gain Ki, and the differential gain Kd. Note that the processing flow is temporarily ended after step S6 or step S8. After the end of this control flow, this control flow shown in FIG. 4 is executed again after a predetermined control cycle has elapsed.

  By performing the processing from steps S1 to S8, the oil temperature Te is estimated based on the relationship between the motor current value Im of the electric oil pump 10 detected during the operation of the electric oil pump 10 and the motor rotational speed N. At the same time, the control parameters (proportional gain Kp, integral gain Ki, and differential gain Kd) for feedback control relating to the motor current value Im or the motor speed N are adjusted based on the estimated oil temperature Te. That is, the PID control by the microcomputer 30 is performed based on the adjusted Kp, Ki, and Kd, so that the optimum hydraulic pressure and discharge oil amount required for the current hydraulic circuit 101 (see FIG. 1) are ensured. A command voltage u (t) (that is, a duty ratio) is determined. Therefore, the motor 11 quickly produces an output for ensuring the hydraulic pressure and the discharge oil amount according to the oil temperature condition. The electric oil pump device 100 in the first embodiment is configured as described above.

(Effect of 1st Embodiment)
In the first embodiment, the following effects can be obtained.

  In the first embodiment, as described above, the oil temperature Te is estimated based on the relationship between the motor current value Im of the electric oil pump 10 detected during the operation of the electric oil pump 10 and the motor rotational speed N, and A microcomputer 30 is provided that adjusts control parameters (proportional gain Kp, integral gain Ki, and differential gain Kd) for feedback control related to the motor current value Im or the motor speed N based on the estimated oil temperature Te. As a result, the output control of the electric oil pump 10 (the current of the motor 11) is adjusted while adjusting the feedback control Kp, Ki and Kd (control parameters) related to the motor current value Im or the motor speed N based on the estimated oil temperature Te. Control), the current motor current value Im can be quickly brought close to the target current value Itg, unlike the case of performing general feedback control without adjusting the control parameter. As a result, by improving the responsiveness of the output control of the motor 11, it is possible to quickly ensure the hydraulic pressure and the discharge oil amount according to the oil temperature condition.

  In the first embodiment, the motor 11 is controlled by PID control including proportional control, integral control, and differential control, and proportional control proportional gain Kp, integral control integral gain Ki, and differential differential control are used as control parameters. The microcomputer 30 is configured to control the gain Kd. Thus, the output control (motor) of the electric oil pump 10 is adjusted while adjusting the proportional gain Kp, integral gain Ki, and differential gain Kd of the feedback control related to the motor current value Im or the motor rotation speed N based on the estimated oil temperature Te. 11 current control) can be performed appropriately.

  In the first embodiment, since the electric oil pump device 100 includes the microcomputer 30 described above, even when the oil viscosity varies according to the oil temperature Te (the load of the electric oil pump 10 varies), the motor 11 can improve the responsiveness of the output control, so that the range of the oil temperature Te (oil viscosity) in which the electric oil pump 10 can be used can be expanded. Even if the design tolerances of the pump unit 12 and the motor 11 constituting the electric oil pump 10 are alleviated (design accuracy is reduced), the output adjustment of the electric oil pump 10 (the motor 11 Current control) can be performed quickly, so that accuracy control in design and manufacture of the electric oil pump 10 can be easily performed.

  In the first embodiment, the microcomputer 30 is configured to determine an excess / deficiency state related to at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump 10 based on the estimated oil temperature Te. Then, the microcomputer 30 is configured to adjust the proportional gain Kp, the integral gain Ki, and the differential gain Kd of the feedback control related to the motor current value Im or the motor rotational speed N so as to avoid this excess / deficiency state. As a result, since the fluctuation of the load (at least one of the hydraulic pressure and the discharge oil amount) of the electric oil pump 10 is grasped according to the estimated oil temperature Te (oil viscosity), along with the fluctuation of the oil temperature Te (oil viscosity) Even when the load of the electric oil pump 10 fluctuates and the possibility of falling into an excess or deficiency state related to at least one of the hydraulic pressure and the discharge oil amount increases, the proportional gain of the feedback control related to the motor current value Im or the motor rotational speed N By adjusting Kp, integral gain Ki, and differential gain Kd, it is possible to reliably avoid falling into this excess / deficiency state. As a result, even when the load of the electric oil pump 10 fluctuates due to fluctuations in the oil temperature Te (oil viscosity), the electric oil pump 10 can be stably operated and The discharged oil amount can be ensured reliably.

  In the first embodiment, the excess / deficiency state is a deficiency state (output deficiency region) of at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump 10 when the estimated oil temperature Te is lower than the threshold value T1. And an excess state (overpower region) of at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump 10 when the estimated oil temperature Te is larger than the threshold value T2. Then, based on the estimated oil temperature Te, the microcomputer 30 is configured to adjust the proportional gain Kp, the integral gain Ki, and the differential gain Kd so as to avoid at least one of an insufficiency state or an excess state.

  Thereby, it is possible to easily estimate the load state of electric oil pump 10 based on whether estimated oil temperature Te (oil viscosity) is lower than threshold value T1 or higher than threshold value T2. Then, the electric oil pump 10 is adjusted by adjusting the proportional gain Kp, the integral gain Ki, and the differential gain Kd of the feedback control related to the motor current value Im or the motor rotational speed N according to the estimated load state (insufficient state or excessive state). It is possible to quickly avoid at least one of the output shortage state or the excessive output state. That is, it is possible to avoid insufficient lubrication of oil in the lubrication system due to an insufficient output state, insufficient hydraulic pressure of the automatic transmission, and insufficient cooling of the cooling jacket due to oil. Further, it is possible to avoid the occurrence of power loss (energy loss) in the electric oil pump 10 due to the overpower state.

  In the first embodiment, the estimated value (oil temperature Te) of the oil temperature during operation of the electric oil pump 10 (during steady operation) is associated with the proportional gain Kp, the integral gain Ki, and the differential gain Kd. The table 4 is provided. Then, the microcomputer 30 is configured to adjust the proportional gain Kp, the integral gain Ki, and the differential gain Kd based on the table 4. Thus, the control parameters (Kp, Ki) are referred to by referring to the table 4 in which the estimated value of the oil temperature Te during the operation of the electric oil pump 10 is associated with the proportional gain Kp, the integral gain Ki, and the differential gain Kd. And output control of the electric oil pump 10 (current control of the motor 11) by adjusting Kd) can be easily performed.

  In the first embodiment, the oil temperature Te is estimated at a predetermined control cycle, and the feedback control proportional gain related to the motor current value Im or the motor rotational speed N is based on the oil temperature Te estimated at the predetermined control cycle. The microcomputer 30 is configured to repeatedly adjust Kp, integral gain Ki, and differential gain Kd. Thus, in a state where the oil temperature Te (oil viscosity) is continuously grasped at a predetermined control period during the operation of the electric oil pump 10, the proportional gain Kp, according to the fluctuation of the oil temperature Te (fluctuation of oil viscosity), Since the integral gain Ki and the differential gain Kd can be adjusted repeatedly, high responsiveness can always be obtained in the output control of the motor 11 during the operation of the electric oil pump 10. Therefore, the load fluctuation of the electric oil pump 10 can be stably followed.

  In the first embodiment, the oil temperature Te is estimated based on the motor current value Im and the motor rotation speed N during the steady operation of the electric oil pump 10, and the motor current value Im is calculated based on the estimated oil temperature Te. Alternatively, the microcomputer 30 is configured to adjust the proportional gain Kp, the integral gain Ki, and the differential gain Kd of the feedback control related to the motor rotational speed N. As a result, it is possible to perform drive control of the electric oil pump 10 that appropriately follows load fluctuations during steady operation of the electric oil pump 10.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIGS. 1, 2, and 4 to 6. In the second embodiment, instead of referring to Table 4 (see FIG. 3) regarding the adjustment of the proportional gain Kp, integral gain Ki, and differential gain Kd in PID control, the estimated value of the oil temperature Te and the proportional gain Kp, A configuration for performing output control of the electric oil pump 10 based on a correlation equation in which a correlation between the integral gain Ki and the differential gain Kd is defined will be described. In the figure, the same reference numerals are given to the same components as those in the first embodiment.

  In the electric oil pump device 200 (see FIG. 1) according to the second embodiment, in each process of steps S6 and S8 in the process flow shown in FIG. 4, Kp for PID control without using the table 4 (see FIG. 3), Ki and Kd are configured to be adjusted.

As an alternative method, specifically, as shown in FIG. 5, when the pump unit 12 is rotated using the motor 11, the equation of motion (the equation of motion for turning the load (pump unit 12) by the motor 11) is: It is shown by the following formula (3).
J × (dω (t) / dt) + B × ω (t) = Kt × u (t) (3)
In the above equation (3), J is the moment of inertia (kgm ² ) related to the rotation of the electric oil pump 10, ω (t) is the rotation speed (rad / s) of the motor 11, and B is the friction coefficient (oil viscosity). , Kt is a torque constant of the motor 11, and u (t) is a command voltage (V). Kt × u (t) is a physical quantity corresponding to the input torque of the motor 11.

In the above equation (3), the transfer function G (s) when the input is K × u (t) and the output is ω (t) is the Laplace transform of the above equation of motion (equation (3)). Therefore, it is shown by the following formula (4). Here, if the Laplace transform of Kt × u (t) is Kt × u (s) and the Laplace transform of ω (t) is ω (s),
G (s) = ω (s) / (Kt × u (s)) = (1 / B) / ((J / B) × s + 1) (4)
The above equation (4) represents a transfer function related to the so-called primary system response.

On the other hand, the transfer function Gc (s) in the PID control is expressed by the following equation (5) by performing Laplace transform on the equation (1) relating to the command voltage u (t) shown in the lower region of FIG.
Gc (s) = Kp + Ki × (1 / s) + Kd × s (5)
In the above equation (5), Kp is a proportional gain, Ki is an integral gain, and Kd is a differential gain.

Here, in the second embodiment, the feedback control for the electric oil pump 10 shown in FIG. 2 is replaced with a block diagram (before equivalent conversion) shown in the left frame of FIG. That is, the transfer element relating to PID control is represented by a transfer function Gc (s), and the transfer element relating to rotation control of the electric oil pump 10 is represented by a transfer function G (s). A feedback transmission element is represented by H (s). In FIG. 6, a block diagram after equivalent conversion (in the right frame) is shown to the right of the block diagram before equivalent conversion (in the left frame). Here, referring to FIG. 6, the transfer function after equivalent conversion in the control system of motor 11 (see FIG. 2) is expressed by the following equation (6).
(Gc (s) × G (s)) / (1 + G (s) × Gc (s) × H (s)) (6)
In the above formula (6), the feedback is assumed to be H (s) = 1.

  Therefore, in the second embodiment, the proportional gain Kp, the integral gain Ki, and the differential gain Kd, which are design parameters for PID control, are calculated based on the transfer function after the equivalent conversion shown in the above equation (6) (see FIG. 6). The microcomputer 30 (see FIG. 1) is configured to be adjusted. As a specific determination method for Kp, Ki, and Kd, a limit sensitivity method proposed by Ziegler Nichols or a transient response method may be applied. Alternatively, methods other than those described above may be used. Thereby, no matter how the estimated oil temperature Te (corresponding to the friction coefficient B (oil viscosity) in the above equation (3)) changes depending on the use conditions of the electric oil pump 10, the above equation (6) ), The control parameters (proportional gain Kp, integral gain Ki, and differential gain Kd) corresponding to the oil temperature Te (friction coefficient B) are appropriately adjusted. In addition, the other structure of 2nd Embodiment is the same as that of the said 1st Embodiment.

(Effect of 2nd Embodiment)
In the second embodiment, the following effects can be obtained.

  In the second embodiment, as described above, the friction coefficient B based on the estimated value (oil temperature Te) of the oil temperature during operation of the electric oil pump 10 (during steady operation) (see the above formula (3)) is proportional. A microcomputer so as to adjust the proportional gain Kp, the integral gain Ki, and the differential gain Kd based on the correlation equation (see the above equation (6)) in which the correlation between the gain Kp, the integral gain Ki, and the differential gain Kd is defined. 30 is configured. Thereby, the correlation formula in which the correlation between the estimated value (oil temperature Te) of the oil temperature during operation of the electric oil pump 10 and the control parameters (Kp, Ki, and Pd) is defined (see the above formula (6)). The output control of the electric oil pump 10 (the current control of the motor 11) by adjusting the control parameters (Kp, Ki and Kd) can be easily performed based on the above. The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

[Modification]
It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the description of the above embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first and second embodiments, the oil is based on the relationship between the motor current value Im detected during operation of the electric oil pump 10 (during steady operation) and the motor rotational speed N of the electric oil pump 10. The temperature Te is estimated, and the control parameters Kp, Ki, and Pd for feedback control related to the motor current value Im or the motor rotation speed N are adjusted based on the estimated oil temperature Te, but the present invention is not limited to this. . For example, the oil temperature Te may be estimated based on the relationship between the torque directly detected from an acceleration sensor attached to the shaft of the motor 11 and the motor rotation speed N of the motor 11, or the pump unit 12. The oil temperature Te may be estimated based on the relationship between the hydraulic pressure discharged from the hydraulic pressure (hydraulic pressure information) and the amount of discharged oil (discharged oil amount information). Further, the microcomputer 30 grasps all of the torque, motor current value Im and hydraulic pressure of the electric oil pump 10 and all of the motor rotational speed N and the amount of discharged oil of the electric oil pump 10, and the mutual detection of these detected values. A predetermined calculation may be performed based on the relationship to estimate the oil temperature Te, and control parameters (Kp, Ki, and Pd) in PID control may be adjusted based on the estimated oil temperature Te.

  In the first and second embodiments, the oil temperature Te is estimated based on the motor current value Im and the motor rotation speed N during steady operation of the electric oil pump 10, and based on the estimated oil temperature Te. Although the control parameters (Kp, Ki, and Pd) of feedback control related to the motor current value Im or the motor rotation speed N are adjusted, the present invention is not limited to this. For example, the oil temperature Te is estimated based on the motor current value Im and the motor rotation speed N not only during steady operation but also when the electric oil pump 10 is started, and Kp, Ki, and Pd are based on the estimated oil temperature Te. You may comprise so that it may adjust.

  Moreover, in the said 1st and 2nd embodiment, although the sensorless three-phase brushless DC motor was used for the motor 11, this invention is not limited to this. That is, the present invention may be applied to output control of the electric oil pump 10 including the motor 11 provided with a position detection sensor such as a Hall element.

  In the first and second embodiments, the example in which the present invention is applied to the start-up control of the electric oil pump 10 mounted on the automobile has been described. However, the present invention is not limited to this. For example, the present invention may be applied to start control of an electric oil pump mounted on an internal combustion engine for equipment.

4 Table 10 Electric oil pump 11 Motor 12 Pump part 20 Motor drive circuit 21 FET circuit 22 Motor drive IC
30 Microcomputer (control unit)
31 Calculation unit (control unit)
32 ROM
40 Battery 41 Shunt resistance 42 Current detection circuit 100, 200 Electric oil pump device 101 Hydraulic circuit Im Motor current value Itg Target current value Kp Proportional gain (control parameter)
Ki integral gain (control parameter)
Kd Differential gain (control parameter)
N Motor speed T1 threshold (first threshold)
T2 threshold (second threshold)
Te oil temperature (estimated oil temperature)

Claims (5)

An electric oil pump including a motor and driven by the motor;
Relationship between at least one of hydraulic pressure, motor current value, or torque of the electric oil pump detected during operation of the electric oil pump, and at least one of discharge oil amount of the electric oil pump or motor rotation speed And a controller that adjusts a control parameter for feedback control related to the motor current value or the motor rotation speed based on the estimated oil temperature.   The control unit determines an excess / deficiency state related to at least one of a hydraulic pressure or a discharge oil amount of the electric oil pump based on the estimated oil temperature, and avoids the excess / deficiency state. The electric oil pump device according to claim 1, wherein the electric oil pump device is configured to adjust the control parameter of feedback control related to the motor rotation speed. The excess / deficiency state includes a deficiency state of at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump when the estimated oil temperature is lower than a first threshold value, and the estimated oil temperature. Including an excess state of at least one of the hydraulic pressure or the discharge oil amount of the electric oil pump in the case of being larger than a threshold value,
The electric control according to claim 2, wherein the control unit is configured to adjust the control parameter so as to avoid at least one of the insufficient state or the excessive state based on the estimated oil temperature. Oil pump device. An estimated value of the oil temperature during operation of the electric oil pump, and a table in which the control parameters are associated with each other;
The electric oil pump device according to claim 1, wherein the control unit is configured to adjust the control parameter based on the table.   The control unit is configured to adjust the control parameter based on a correlation equation in which a correlation between an estimated value of oil temperature during operation of the electric oil pump and the control parameter is defined. The electric oil pump device according to any one of claims 1 to 3.

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