JP2004316868A - Control device for electromagnetic actuator - Google Patents

Abstract

An object of the present invention is to provide a control device of an electromagnetic actuator having improved current rise response.
A control device for an electromagnetic actuator, comprising: a detector for detecting a gap between a core member and an armature member; a current detector for detecting an actual current flowing through a solenoid; and an actual current matching a target current. And a feedback controller that performs feedback control to perform the feedback control. The control device further includes a feedforward controller that performs feedforward control of the target current, and a PWM duty signal generator that generates a PWM duty signal based on outputs of the feedback controller and the feedforward controller. According to the gap detected by the gap detector, the feedback controller changes the integral term constant, and the feedforward controller changes the transfer function and / or the gain.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for an electromagnetic actuator used in a torque transmission mechanism of an electronically controlled four-wheel drive vehicle or the like.
[0002]
[Prior art]
For example, a torque transmission mechanism or the like of an electronically controlled four-wheel drive vehicle includes a pair of left and right planetary gear sets and a pair of brake mechanisms (clutch mechanisms) for variably controlling the torque of a sun gear connected to each planetary gear set. . Each brake mechanism (clutch mechanism) includes a wet-type multi-plate brake (clutch) and an electromagnetic actuator that operates the multi-plate brake (clutch).
[0003]
The electromagnetic actuator includes a core (yoke) having an annular groove, a solenoid inserted into the annular groove of the core, an armature arranged to face the core with a predetermined gap, and a piston connected to the armature. It is composed of
[0004]
When a current is applied to the solenoid, the armature is attracted to the core by the solenoid to generate thrust. By this thrust, a piston connected integrally with the armature presses the multi-plate brake (clutch), thereby generating a brake torque (clutch torque).
[0005]
By controlling the current value flowing through the left and right solenoids based on the turning direction and the steering force or the steering angle, the output torque to the left and right rear axles can be variably controlled.
[0006]
As a conventional drive current control method for a solenoid, a combination of current feedback control using a PID controller and current control by a pulse width modulation (PWM) duty signal using a switching element and a diode for current return is generally used. Is being done.
[0007]
By adjusting the proportional term constant, the integral term constant, and the differential term constant of the PID controller to optimal values, the steady-state deviation of the drive current (actual current) with respect to the target current is eliminated, and an appropriate overshoot occurs at the time of the rise of the current. Operate.
[0008]
[Patent Document 1]
JP-A-2002-39231
[Patent Document 2]
Japanese Patent Application Laid-Open No. 2002-225581
[Patent Document]
JP 2002-227882 A
[Problems to be solved by the invention]
However, in the current feedback control using the conventional PID controller, there is a problem that the actual current with respect to the target current at the time of the rise of the current is delayed, the responsiveness of the driving torque is deteriorated, and the vehicle behavior becomes defective.
[0012]
Further, the brake (clutch) plate and the brake (clutch) disk of the wet multi-disc brake (clutch) deteriorate due to aging (wear), and accordingly, the initial gap between the core and the armature when the solenoid is not energized decreases. . When the initial gap decreases, there is a problem that the inductance component of the solenoid increases, and the responsiveness at the time of starting current deteriorates.
[0013]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a control device for an electromagnetic actuator that can improve the rising characteristics of current in PWM duty driving of a solenoid.
[0014]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a core member having a groove, a solenoid housed in the groove of the core member, and an armature member arranged to face the core member with a gap. A control device for an electromagnetic actuator, comprising: means for detecting a gap between the core member and the armature member; current detecting means for detecting an actual current flowing through the solenoid; and A feedback controller for performing feedback control on the target current, a feedforward controller for performing feedforward control of the target current, and a solenoid drive signal generating means for generating a solenoid drive signal based on outputs of the feedback controller and the feedforward controller. The feedback controller detects by the gap detecting means. Depending on which gap, the control device of an electromagnetic actuator is provided, characterized in that to change the integral term constant.
[0015]
According to this configuration, the feedback controller changes the integral term constant in accordance with the gap detected by the gap detection means, so that the rising characteristics of the actual current can be improved and the convergence to the steady state can be quickly performed by the feedback control. Can be achieved.
[0016]
According to the second aspect of the present invention, there is provided a control device for an electromagnetic actuator that changes a transfer function and / or a gain in accordance with a gap detected by a gap detection unit by a feedforward controller.
[0017]
According to this configuration, the transfer function and / or the gain of the feedforward controller is changed according to the gap, so that an appropriate overshoot can be generated at the rise of the actual current, and the rise characteristic of the actual current according to the gap. Can be improved. Therefore, according to the second aspect of the invention, the rising response of the actual current can be more finely improved in combination with the effect of the first aspect of the invention.
[0018]
According to the third aspect of the present invention, there is provided an electromagnetic actuator control device in which the feedback controller selects a large integral term constant when the gap is large, and selects a smaller integral term constant as the gap becomes small.
[0019]
According to this configuration, a smaller integral term constant is selected as the gap becomes smaller, so that the response to the rise of the actual current can be improved, and convergence to the steady state can be quickly achieved by feedback control.
[0020]
According to the fourth aspect of the present invention, there is provided a core member having a groove, a solenoid housed in the groove of the core member, and an armature member arranged to face the core member with a gap. A control device for an electromagnetic actuator, comprising: means for detecting a gap between the core member and the armature member; current detecting means for detecting an actual current flowing through the solenoid; and A feedback controller for performing feedback control on the target current, a feedforward controller for performing feedforward control of the target current, and a solenoid drive signal generating means for generating a solenoid drive signal based on outputs of the feedback controller and the feedforward controller. Wherein the feedforward controller comprises the gap detecting means. In accordance with the detected gap, the control device of an electromagnetic actuator is provided, characterized in that to change the transfer function and / or gain.
[0021]
According to this configuration, since the transfer function and / or the gain of the feedforward controller is changed according to the gap, an appropriate overshoot can be generated at the rise of the actual current, and the responsiveness of the rise of the actual current can be improved. Can be improved.
[0022]
According to the fifth aspect of the present invention, the feedforward controller controls the electromagnetic actuator to select a small transfer function and / or a small gain when the gap is large, and to select a larger transfer function and / or the gain as the gap is small. An apparatus is provided.
[0023]
The inductance component of the solenoid is small when the gap is large, and increases as the gap becomes small. Therefore, as the gap becomes smaller, the rising response of the actual current becomes worse. Therefore, as the gap becomes smaller, a large transfer function and / or a large gain is selected to perform feedforward control of the target current. In addition, an appropriate overshoot can be generated at the rise of the actual current, and the response to the rise of the actual current can be improved.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to FIG. 1, there is shown a schematic view of a power transmission device for a four-wheel drive vehicle based on a front engine front drive (FF) vehicle to which the solenoid drive device of the present invention can be applied.
[0025]
As shown in FIG. 1, the power transmission system includes a front differential device 6 in which the power of an engine 2 arranged in front of the vehicle is transmitted from an output shaft 4 a of a transmission 4, and a power from the front differential device 6 which is a propeller shaft. The transmission mainly includes a speed increasing device (transmission device) 10 transmitted via the transmission 8 and a rear differential device 12 to which power from the speed increasing device 10 is transmitted.
[0026]
The front differential device 6 has a conventionally well-known structure, and transmits the power from the output shaft 4a of the transmission 4 to the left and right front wheel drive shafts 20 and 22 via the plurality of gears 14 and the output shafts 16 and 18 in the differential case 6a. The transmission drives each front wheel.
[0027]
As will be described later, the rear differential device 12 includes a pair of planetary gear sets and a pair of electromagnetic actuators for controlling engagement of a multi-plate brake mechanism (multi-plate clutch mechanism), and controls the electromagnetic actuator. By transmitting power to the left and right rear wheel drive shafts 24 and 26, each rear wheel is driven.
[0028]
FIG. 2 is a cross-sectional view of a speed increasing device (transmission device) 10 and a rear differential device 12 disposed downstream of the speed increasing device 10. The speed increasing device 10 includes an input shaft 30 rotatably mounted in a casing 28 and an output shaft (hypoid pinion shaft) 32.
[0029]
The speed increasing device 10 further includes an oil pump subassembly 34, a planetary carrier subassembly 38, a direct coupling clutch subassembly 40, and a speed change brake 42.
[0030]
The rear differential device 12 provided on the downstream side of the speed increasing device 10 has a hypoid pinion gear 44 formed at the tip of the hypoid pinion shaft 32.
[0031]
The hypoid pinion gear 44 meshes with the hypoid ring gear 48, and the power from the hypoid ring gear 48 is input to the ring gears of the pair of planetary gear sets 50A and 50B provided on the left and right.
[0032]
The sun gears of the planetary gear sets 50A and 50B are rotatably mounted around the left rear axle 24 and the right rear axle 26. The planetary carriers of the planetary gear sets 50A and 50B are fixed to the left rear axle 24 and the right rear axle 26. A planet gear carried on the planetary carrier meshes with the sun gear and the ring gear.
[0033]
The left and right planetary gear sets 50A and 50B are connected to a brake mechanism 51 (clutch mechanism) provided for variably controlling the torque of the sun gear. The brake mechanism (clutch mechanism) 51 includes a wet multi-plate brake (clutch) 52 and an electromagnetic actuator 56 that operates the multi-plate brake (clutch) 52.
[0034]
The brake (clutch) plate of the wet multi-plate brake (clutch) 52 is fixed to the casing 54, and the brake (clutch) disk is fixed to the sun gear of the planetary gear sets 50A and 50B.
[0035]
The electromagnetic actuator 56 includes a ring-shaped core (yoke) 58 having an annular groove, an annular solenoid 60 inserted into the annular groove of the ring-shaped core 58, and a ring-shaped opposed to the ring-shaped core 58 with a predetermined gap. It comprises an armature 62 and an annular piston 64 connected to the armature 62.
[0036]
When a current is applied to the solenoid 60, the armature 62 is attracted to the core 58 by the solenoid 60, and a thrust is generated. By this thrust, a piston (64) integrally connected to the armature (62) presses the multi-plate brake (clutch) 52, thereby generating a brake (clutch) torque.
[0037]
Thus, the sun gears of the planetary gear sets 50A, 50B are fixed to the casing 54, respectively, and the driving force of the hypoid pinion shaft 32 is transmitted via the ring gears, the planet gears, and the planet gears of the planetary gear sets 50A, 50B, the left and right rear axles 24, 26.
[0038]
By controlling the current flowing through the annular solenoid 60, the driving force of the input shaft 30 can be arbitrarily distributed to the left and right rear axles 24, 26 in a directly connected state or by increasing the speed by the speed increasing device 10, so that it is optimal. Turning control can be realized.
[0039]
A search coil 66 is attached adjacent to each solenoid 60. The search coil 66 detects the strength of the magnetic flux when the solenoid 60 is energized, estimates the gap based on the detected strength of the magnetic flux, and performs feedback and feedforward control corresponding to the gap.
[0040]
Referring to FIG. 3, there is shown a principle diagram of a control device for an electromagnetic actuator of the present invention. The electromagnetic actuator has a core member having a groove, a solenoid 60 housed in the groove of the core member, and an armature member arranged to face the core member with a gap.
[0041]
The control device of the electromagnetic actuator is constituted by a feedforward type two-degree-of-freedom control system, and includes an initial gap detecting means 70 for detecting an initial gap between the core member and the armature member when the operation of the solenoid 60 is started. . The initial gap detecting means 70 detects a gap when the solenoid operation is stopped or when the operation is started, or averages the gaps to determine an initial gap.
[0042]
The actual current flowing through the solenoid 60 is detected by the current detecting means 72. The target current (command current) is input to the subtractor 76 via the target filter 74.
[0043]
The target filter 74 is a temporary filter obtained by dividing the actual current by the target current, and the response of the entire control device is determined by the characteristics of the target filter.
[0044]
The actual current detected by the current detecting means 72 is subtracted from the target current passed through the target filter 74 by the subtracter 76, and the difference is input to the PID controller (feedback controller) 78. The PID controller 78 performs feedback control so that the actual current matches the target current.
[0045]
The PID controller 78 changes the integral term constant according to the initial gap detected by the initial gap detection means 70. For example, one of a plurality of preset integral term constants is selected according to the initial gap.
[0046]
The feedforward controller 80 performs target feedforward control of the target current. That is, the feedforward controller 80 changes the transfer function and the gain in accordance with the initial gap detected by the initial gap detection means 70, and performs feedforward control of the target current.
[0047]
For example, the feedforward controller 80 selects one of a plurality of preset transfer functions and a plurality of gains according to the initial gap.
[0048]
The output of the PID controller 78 and the output of the feedforward controller 80 are added by an adder 82, and the sum is input to a pulse width modulation (PWM) duty signal generating means (solenoid drive signal generating means) 84.
[0049]
The PWM duty signal generation means 84 generates a PWM duty signal (solenoid drive signal) based on the sum of the outputs of the PID controller 78 and the feedforward controller 80, and drives the solenoid 60 based on the PWM duty signal.
[0050]
When an actual current flows through the solenoid 60, the armature 62 of the electromagnetic actuator 56 shown in FIG. 2 is attracted to the core 58 by the solenoid 60 to generate a thrust. By this thrust, a piston (64) integrally connected to the armature (62) presses the multi-plate brake (clutch) 52, thereby generating a brake (clutch) torque.
[0051]
The configuration of the PID controller 78 according to the embodiment of the present invention will be described with reference to FIG. The PID controller 78 has a proportional term constant 86, five integral term constants 88 # 1 to 88 # 5, and a differential term constant 100.
[0052]
The value of the proportional term constant 86 is, for example, 2. The value of the integral term constants 88 # 1 and 88 # 2 is 0.6, the value of the integral term constants 88 # 3 is 0.5, and the value of the integral term constants 88 # 4 and 88 # 5 is 0.33. It is.
[0053]
The integral term constant 88 # 1 is applied when the initial gap is large, and the integral term constants 88 # 2 to 88 # 5 are applied as the initial gap becomes smaller. Of course, the values of the five integral term constants 88 # 1 to 88 # 5 may be set to different values.
[0054]
The PID controller 78 further has a differential term constant 100. In this embodiment, since the value of the differential term constant 100 is 0, the differential term control is not actually performed.
[0055]
The magnetic flux intensity detected by the search coil 66 is converted into an initial gap by a map 90 in which the magnetic flux intensity is associated with the initial gap. 1 to 88 # 5 are selected.
[0056]
The target current is input to a subtractor 76 via a target filter 74, the actual current is subtracted from the target current by the subtracter 76, and the difference is input to a PID controller 78.
[0057]
In the calculation of the proportional term by the PID controller 78, the output of the subtractor 76 is multiplied by the proportional term constant 2 and the product is input to the adder 106. In the calculation of the integral term, the output of the subtractor 76 is multiplied by an integral term constant selected according to the initial gap, for example, 0.6, and the product is input to the adder 94.
[0058]
In the adder 94, the current value and the previous value 98 output from the multipoint switch 92 are added, and the sum is input to the adder 106 via the limiter 96.
[0059]
In the operation of the differential term, the output of the subtractor 76 is multiplied by the differential term constant 0, the previous value 104 is subtracted from the product by the subtractor 102, and the difference is input to the adder 106. As described above, since the value of the differential term constant 100 is 0 in this embodiment, the differential term calculation is not performed.
[0060]
The adder 106 adds the value of the proportional term, the value of the integral term, and the value of the derivative term, and outputs the sum through a limiter 108.
[0061]
In the PID controller 78 of the present embodiment, a large integral term constant is set when the initial gap is large, and the integral term constant is set so as to gradually decrease as the initial gap decreases. Such a set value is based on a learning value learned in advance by an experiment.
[0062]
As described above, since the optimum integral term constant is selected in accordance with the detected initial gap, it is possible to improve the responsiveness of the rise of the actual current at the time of the PWM drive, and to quickly achieve the convergence to the target current. it can.
[0063]
FIG. 5 shows the configuration of the feedforward controller 80 according to the embodiment of the present invention. The feedforward controller 80 has five transfer functions 110 # 1 to 110 # 5 and five gains 116 # 1 to 116 # 5.
[0064]
The transfer functions 110 # 1 to 110 # 5 are arranged in ascending order of value, and when the initial gap is large, the smallest transfer function 110 # 1 is selected. As the initial gap becomes smaller, the transfer functions 110 # 2 to 110 # 5 are selected. Is selected.
[0065]
Similarly, the gains 116 # 1 to 116 # 5 are arranged in ascending order of the values. When the initial gap is large, the smallest gain 116 # 1 is applied, and as the initial gap becomes smaller, the gains 116 # 2 to 116 # 5 become smaller. Is applied.
[0066]
The magnetic flux intensity detected by the search coil 66 is converted to an initial gap by a magnetic flux intensity-initial gap conversion map 112. Based on this initial gap, the multipoint switch 114 selects an optimal transfer function, for example, the transfer function 110 # 2, and the multipoint switch 118 selects a gain 116 # 2 corresponding to the transfer function 110 # 2.
[0067]
The target current value is multiplied by the selected transfer function 110 # 2, and the product is supplied to the multiplier 120. Similarly, the target current value is multiplied by the selected gain 116 # 2, and the product is supplied to the multiplier 120. The multiplier 120 multiplies the transfer function 110 # 2 by the gain 116 # 2, and outputs the product via the limiter 122.
[0068]
The output of the multiplier 120 and the output of the adder 106 shown in FIG. 4 are supplied to the adder 82 shown in FIG. 3 and added, and the PWM duty signal generating means 84 generates a PWM duty signal based on the sum.
[0069]
In the feedforward controller 80 of the present embodiment, a small transfer function and a small gain are selected when the initial gap is large, and larger transfer functions and gains are selected as the multiple disc brake 52 is worn and the initial gap becomes smaller. .
[0070]
The inductance component of the solenoid 60 is small when the initial gap is large, and increases as the multiple disc brake 52 is worn and the initial gap is reduced.
[0071]
Therefore, as the initial gap becomes smaller, the rising response of the actual current becomes worse. Therefore, in the present embodiment, a larger transfer function and a larger gain are selected as the initial gap becomes smaller, and the target current is subjected to feedforward control.
[0072]
By controlling in this way, it is possible to improve the rising response of the actual current regardless of the size of the initial gap.
[0073]
In the embodiment described above, the PID controller 78 selects the optimum value according to the initial gap from the plurality of integral term constants, and the feedforward controller 80 selects the optimum value from the plurality of transfer functions and gains according to the initial gap. Optimal transfer function and gain are selected.
[0074]
The control device of the electromagnetic actuator of the present invention is not limited to the above-described embodiment. May be changed according to the initial gap.
[0075]
Similarly, the integral term constant of the PID controller 78 may be fixed to one value, and the transfer function and the gain of the feedforward controller 80 may be changed according to the initial gap.
[0076]
FIG. 6 shows the current rise characteristics of the embodiment of the present invention and the conventional example only of the feedback control when the indicated torque is 0 to 120 kgfm. Curve A shows the current rise characteristics of the present invention when the initial gap is 1.4 mm, and curve B shows the current rise characteristics when the initial gap is 0.4 mm. On the other hand, curve C shows the current rise characteristics of the conventional method when the initial gap is 1.4 mm, and curve D shows the current rise characteristics when the initial gap is 0.4 mm.
[0077]
As is clear from FIG. 6, the time required for the current to rise to 80% of the target current, that is, 0.8 A, is about 50 msec for both the curves A and B, which are compared with the curves C and D of the current rise characteristics of the conventional method. And clearly has a good start-up response.
[0078]
Further, by providing a large amount of feedforward control as the initial gap becomes smaller and performing control so that a large overshoot occurs, a similarly improved rise response of the actual current can be obtained regardless of the size of the initial gap. Can be. After the real current is quickly started, the target current can be quickly approached by the feedback control.
[0079]
【The invention's effect】
According to the first aspect of the present invention, the feedback controller changes the integral term constant in accordance with the gap detected by the gap detection means, so that the rising characteristic of the actual current can be improved and the feedback control can return to the steady state. Convergence can be achieved quickly.
[0080]
According to the second aspect of the present invention, since the transfer function and / or the gain of the feedforward controller is changed according to the gap, an appropriate overshoot can be generated at the rise of the real current, and the real current can be changed according to the gap. Can be improved. Therefore, according to the second aspect of the present invention, it is possible to more finely improve the rising response of the actual current in combination with the effect of the first aspect of the present invention.
[0081]
According to the third aspect of the present invention, since the optimum integral term constant is selected according to the detected gap, the responsiveness of the rise of the actual current can be improved, and the convergence to the target current can be achieved quickly. .
[0082]
According to the fourth aspect of the present invention, the transfer function and / or the gain of the feedforward controller is changed according to the gap, so that an appropriate overshoot can be generated at the rise of the actual current, and the actual current can be reduced. The rising response can be improved.
[0083]
The inductance component of the solenoid is small when the gap is large, and increases as the gap becomes small. Therefore, as the gap becomes smaller, the rising response of the actual current becomes worse. In the invention of claim 5, a larger transfer function and / or a larger gain is selected as the gap becomes smaller. Appropriate overshoot can be generated, and the rise response of the actual current can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a power transmission system of a four-wheel drive vehicle.
FIG. 2 is a sectional view of a speed increasing device (transmission device) and a rear differential device.
FIG. 3 is a block diagram showing a principle configuration of a control device of the electromagnetic actuator of the present invention.
FIG. 4 is a diagram illustrating a configuration of a PID controller according to the embodiment of the present invention.
FIG. 5 is a diagram illustrating a configuration of a feedforward controller according to the embodiment of the present invention.
FIG. 6 is a diagram showing current rise characteristics of the present invention and a conventional example when an indicated torque is 0 to 120 kgfm.
[Explanation of symbols]
10 Speed increasing device (transmission)
12 Rear differential device 24, 26 Rear axle 30 Input shaft 32 Output shaft (hypoid pinion shaft)
50A, 50B Planetary gear set 51 Brake mechanism 52 Wet multi-plate brake 56 Electromagnetic actuator 58 Core (yoke)
Reference Signs List 60 Annular solenoid 62 Armature 66 Search coil 70 Initial gap detecting means 72 Current detecting means 74 Target filter 78 PID controller 80 Feedforward controller 84 PWM duty signal generating means

Claims (5)

A control device for an electromagnetic actuator having a core member having a groove, a solenoid housed in the groove of the core member, and an armature member arranged to face the core member with a gap,
Means for detecting a gap between the core member and the armature member,
Current detection means for detecting an actual current flowing through the solenoid,
A feedback controller that performs feedback control so that the actual current matches the target current;
A feedforward controller for feedforward controlling the target current,
Solenoid drive signal generating means for generating a solenoid drive signal based on the output of the feedback controller and the feedforward controller,
The control device for an electromagnetic actuator, wherein the feedback controller changes an integral term constant according to the gap detected by the gap detection unit. 2. The control device for an electromagnetic actuator according to claim 1, wherein the feedforward controller changes a transfer function and / or a gain according to the gap detected by the gap detection unit. 2. The electromagnetic actuator control device according to claim 1, wherein the feedback controller selects a large integral term constant when the gap is large, and selects a smaller integral term constant as the gap becomes small. A control device for an electromagnetic actuator having a core member having a groove, a solenoid housed in the groove of the core member, and an armature member arranged to face the core member with a gap,
Means for detecting a gap between the core member and the armature member,
Current detection means for detecting an actual current flowing through the solenoid,
A feedback controller that performs feedback control so that the actual current matches the target current;
A feedforward controller for feedforward controlling the target current,
Solenoid drive signal generating means for generating a solenoid drive signal based on the output of the feedback controller and the feedforward controller,
The control device for an electromagnetic actuator, wherein the feedforward controller changes a transfer function and / or a gain according to the gap detected by the gap detection unit. 5. The control device according to claim 4, wherein the feedforward controller selects a small transfer function and / or a small gain when the gap is large, and selects a larger transfer function and / or a gain when the gap is small.

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