JP2004208442A - Driver-controller for actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driver-controller for actuator, capable of preventing noise from being produced when a motor is started or stopped. <P>SOLUTION: One of the lower arms of an H-bridge circuit 51 is constituted, by connecting two field-effect transistors T3A and T3B in parallel, and the other of the lower arms is constituted, by connecting two field-effect transistors T4A and T4B in parallel. Letting the driving capability of the individual transistors T1 and T2 of the upper arm be 1, the driving capability of the transistors T3A and T4A is set to 1/3, and that of the transistors T3B and T4B is set to 2/3. When a motor 30 is driven in normal rotation, an actuator driving output control circuit 50 controls and turns on the transistors T1 and T4A and then controls turns on the transistor T4B to a turned-on state. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drive control device for an actuator that drives and controls an actuator that opens and closes a mix door of, for example, an air conditioner for a vehicle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an actuator drive control device that drives and controls a mix door actuator has been known.
[0003]
Such an actuator drive control device includes a drive circuit that drives an actuator having a DC electric motor, and a drive control circuit that controls the drive circuit to control the rotation of the electric motor. The drive control circuit controls a drive circuit so that the mix door is positioned at the target position by comparing the detection signal of the detection means for detecting the rotational position of the mix door with a target value.
[0004]
The drive circuit of the actuator drive control device is configured by an H-bridge circuit including four MOS transistors and the like for rotating the DC electric motor forward and backward. For example, as shown in FIG. 9, the H-bridge circuit 100 includes four transistors T1 to T4 (see, for example, Patent Document 1). Reference numeral 30 denotes an electric motor.
[0005]
[Patent Document 1]
JP-A-10-266691 (paragraphs 33 and 34, FIG. 2)
[0006]
[Problems to be solved by the invention]
However, in such an actuator drive control device, when the motor is started or stopped, the transistors T1 to T4 of the H-bridge circuit 100 turn on and off, so that the output of the motor rapidly changes. For this reason, there is a problem that noise is generated due to the backlash of the gear, and the noise becomes annoying especially in recent years when the interior of the vehicle is quiet.
[0007]
An object of the present invention is to provide a drive control device for an actuator that can prevent generation of noise when the motor is started or stopped.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 includes a driving unit for driving an actuator having an electric motor, and a driving control unit for controlling the driving unit to control the rotation of the electric motor. The means is a drive control device for an actuator having an H-bridge circuit composed of a switching semiconductor element,
One of the first switching semiconductor elements of the lower arm of the H-bridge circuit is composed of a plurality of first parallel switching semiconductor elements connected in parallel, and the sum of the respective capabilities of the first parallel switching semiconductor elements is determined by the first switching semiconductor element. The ability of the element
The other second switching semiconductor element of the lower arm is composed of a plurality of second parallel switching semiconductor elements connected in parallel, and the sum of the respective capabilities of the second parallel switching semiconductor element is defined as the capability of the second switching semiconductor element. ,
The first and second parallel switching semiconductor elements are individually switched and controlled.
[0009]
According to a second aspect of the present invention, the H-bridge circuit is formed on one semiconductor chip, and the first and second switching devices are connected in parallel within an area on the semiconductor chip on which the first and second switching semiconductor elements are formed. A parallel switching semiconductor element is formed.
[0010]
According to a third aspect of the present invention, the drive control means may be configured such that the total capability of each of the first and second parallel switching semiconductor elements increases stepwise, or the total capability decreases stepwise. The switching control of each of the first and second parallel switching semiconductor elements is performed by a suitable combination.
[0011]
Embodiment
Hereinafter, an embodiment of an automotive air conditioner to which an actuator drive control device according to the present invention is applied will be described with reference to the drawings.
[0012]
In FIG. 1, reference numeral 1 denotes a main body of an air conditioner for a vehicle. This main body 1 is, like a general air conditioner for a vehicle, an intake unit 2 for selectively taking in outside air or inside air, and a cooling unit for cooling intake air. The air conditioner includes a unit 3 and a heater unit 4 that blows out the conditioned air into the vehicle compartment after the intake air is conditioned and temperature-controlled.
[0013]
The intake unit 2 is provided with an outside air intake 5 for taking in outside air and an inside air intake 6 for taking in inside air, and a connection portion between these intakes 5 and 6 regulates a ratio of outside air and inside air taken into the unit. An intake door (driven mechanism) 7 is provided rotatably. The intake door 7 is rotated by an electric motor type actuator 30A shown in FIG.
[0014]
FIG. 2 is a view showing a specific example of the electric motor type actuator according to the present invention. The electric motor type actuator 30A includes an electric motor 30, a worm 30c mounted on an output shaft 30b of the electric motor 30, a reduction gear train mechanism 30e meshed with the worm 30c, and a worm 30c and a reduction gear train mechanism 30e. And an actuator lever 30L that is turned. The rotation of the actuator lever 30L is transmitted to the intake door 7 shown in FIG. 1 via a link mechanism (not shown), so that the intake door 7 is rotated. Further, the rotation position of the intake door 7 is detected by a potentiometer 31.
[0015]
As shown in FIG. 1, the intake unit 2 includes a fan 10 rotated at a predetermined speed by a fan motor 9. By the rotation of the fan 10, the outside air or the inside air is selectively sucked from the outside air intake 5 or the inside air intake 6 depending on the position of the intake door 7, and the voltage applied to the fan motor 9 is varied to change the fan 10. By changing the rotation speed of the vehicle, the amount of air blown into the vehicle interior is adjusted. When the intake door 7 is at the position A in the drawing, the outside air is introduced (FRE), and when the intake door 7 is at the position B in the drawing, the inside air circulation (REC) is performed.
[0016]
An evaporator 11 constituting a refrigeration cycle is provided in the cooling unit 3, and a refrigerant is supplied to the evaporator 11 by operating a compressor (not shown), and the intake air is cooled by heat exchange with the refrigerant.
[0017]
A heater core 12 through which engine cooling water is circulated is provided in the heater unit 4, and the ratio of the amount of air passing through the heater core 12 to the amount of air bypassing the heater core 12 is provided upstream of the heater core 12. A mix door 13 for adjustment is provided rotatably. The mix door 13 is also rotated via a link mechanism (not shown) by the electric motor type actuator 30A in the same manner as described above. By changing the opening degree of the mix door 13, the mixing ratio of the warm air heated by the heat exchange with the engine cooling water through the heater core 12 and the unheated cool air bypassing the heater core 12 is varied. The temperature of the air blown into the room is adjusted. The turning position of the mix door 13 is detected by the potentiometer 31 as described above.
[0018]
The adjusted air is supplied into the vehicle cabin from one of the differential outlet 15, vent outlet 16, and foot outlet 17. A differential door 18, a vent door 19, and a foot door 20 are rotatably provided at these air outlets 15 to 17, respectively, and are rotated by an electric motor type actuator (not shown) via a link mechanism (not shown). The blowing mode is arbitrarily set by combining the open / close states of the outlets 15 to 17.
[0019]
FIG. 3 is a block diagram showing a configuration of a control unit (actuator drive control device) 40 that controls the actuator 30A and the like. The control unit 40 receives a power supply from a battery power supply + B to generate a 5V power supply, a 5V power supply circuit 41, a built-in power supply protection circuit 42 for protecting the 5V power supply circuit 41, and a main control unit (not shown). A LAN input circuit 43 for receiving data, a LAN output circuit 44 for transmitting data to a main control unit (not shown), a communication ID input setting circuit 80 for setting an ID code for identifying each control unit 40, The data having the same ID code as the ID code set by the communication ID input setting circuit 80 is extracted from the data received by the circuit 43, or the ID code set by the communication ID input setting circuit 80 to necessary data. And a LAN communication processing circuit 45 that outputs the result to the LAN output circuit 44. Obtain.
[0020]
Further, the control unit 40 includes a data latch circuit 46 for holding data extracted by the LAN communication processing circuit 45, a D / A converter 47 for D / A converting the data held by the data latch circuit 46, and a mixed door 13 The input circuit 48 for inputting the output voltage of the potentiometer 31 for detecting the opening of the potentiometer 31 compares the output voltage of the potentiometer 31 supplied via the input circuit 48 with the voltage output from the D / A converter 47. A comparator 49 for outputting an output signal corresponding to the difference between them, and an actuator drive output control circuit (drive control means) for generating and outputting a control signal for controlling the electric motor 30 based on the output signal of the comparator 49. ) 50 and an H block for driving the electric motor 30 based on the control signal output from the actuator drive output control circuit 50. Tsu di circuits and a (driving means) 51.
[0021]
The control unit 40 includes an overcurrent detection circuit 53 that generates an overcurrent detection output when the current supplied to the electric motor 30 via the H-bridge circuit 51 exceeds a preset allowable value. An overvoltage detection circuit 54 that generates an overvoltage detection output when the applied voltage (voltage of the battery power supply + B) exceeds a preset allowable value, and a temperature detection element (not shown) such as a thermistor to which the electric motor 30 is attached. And an over-temperature detection circuit 55 that monitors the temperature of the electric motor 30 on the basis of the detected output and generates an over-temperature detection output when the temperature of the electric motor 30 exceeds a preset allowable temperature. The detection outputs of these detection circuits 53, 54, 55 are supplied to an actuator drive output control circuit 50. When the detection circuits 53, 54, and 55 detect overcurrent, overvoltage, and overtemperature, the actuator drive output control circuit 50 stops driving the electric motor 30 so that the H-bridge circuit 51 and the The motor 30 is protected.
[0022]
FIG. 4 is a circuit diagram of the H-bridge circuit and its peripheral circuits. The H-bridge circuit 51 includes first and second MOS field effect transistors (hereinafter, referred to as transistors) T1 and T2 forming an upper arm and two transistors connected in parallel forming one of the lower arms (First parallel switching semiconductor element) T3A, T3B, and two transistors (first parallel switching semiconductor element) T4A, T4B that constitute the other of the lower arm and are connected in parallel. Then, a first switching semiconductor element is configured by the transistor T3A and the transistor T3B, and a second switching semiconductor element is configured by the transistor T4A and the transistor T4B.
[0023]
The actuator drive output control circuit 50 and the H-bridge circuit 51 are integrated on one semiconductor chip 90 as shown in FIG.
[0024]
The transistors T3A and T4A of the H-bridge circuit 51 are formed below the transistors T1 and T2 of the upper arm (in FIG. 8). The area on the semiconductor chip 90 on which the transistors T3A and T4A are formed is the same as that of the transistors T1 and T2. The area is set to 1/3 of the formed area, and the performance of the transistors T3A and T4A is 1/3 of the performance of the transistors T1 and T2. The transistors T3B and T4B are formed below the transistors T3A and T4A (in FIG. 8), and the area on the semiconductor chip 90 on which the transistors T3B and T4B are formed is 2/2 of the area on which the transistors T1 and T2 are formed. The capacity of the transistors T3B and T4B is set to 2/3 of the capacity of the transistors T1 and T2.
[0025]
As described above, since the value obtained by adding the area of the transistors T3A and T4A and the area of the transistors T3B and T4B becomes the area of the transistors T1 and T2, the size of the semiconductor chip 90 does not need to be increased. It has the same size as a conventional semiconductor chip.
[0026]
The actuator drive output control circuit 50 determines whether it is necessary to drive the electric motor 30 based on the output voltage of the comparator 49. Specifically, when the output voltage of the comparator 49 is higher than the reference voltage by a predetermined value or more, the actuator drive output control circuit 50 needs to drive the electric motor 30 forward to drive the door in the opening direction. Judge that there is. When the output voltage of the comparator 49 is lower than the reference voltage by a predetermined value or more, the actuator drive output control circuit 50 determines that it is necessary to drive the electric motor 30 in the reverse direction to drive the door in the closing direction. When the output voltage of the comparator 49 is within a predetermined value range with respect to the reference voltage, the actuator drive output control circuit 50 determines that the electric motor 30 needs to be stopped.
[0027]
When driving the electric motor 30 in the forward direction, the actuator drive output control circuit 50 outputs a gate drive signal of the transistor T1 from the gate drive signal output terminal Q1 and drives the gate of the transistor T4A from the gate drive signal output terminal Q4A. Output a signal. The actuator drive output control circuit 50 outputs the gate drive signal of the transistor T4B from the gate drive signal output terminal Q4B when a predetermined time has elapsed since the gate drive signal of the transistor T4A was output from the gate drive signal output terminal Q4A. I do.
[0028]
When stopping the electric motor 30 from driving in the normal direction, the actuator drive output control circuit 50 first outputs a gate drive signal for the transistor T4B, and when a predetermined time has elapsed, the gate drive signal for the transistor T1. Stop output of
[0029]
When starting the electric motor 30 in the reverse rotation direction, the actuator drive output control circuit 50 outputs a gate drive signal of the transistor T2 from the gate drive signal output terminal Q2 and a gate drive signal of the transistor T3A from the gate drive signal output terminal Q3A. Is output. The actuator drive output control circuit 50 outputs the gate drive signal of the transistor T3B from the gate drive signal output terminal Q3B when a predetermined time has elapsed since the gate drive signal of the transistor T3A was output from the gate drive signal output terminal Q3A. I do.
[0030]
To stop the electric motor 30 from driving in the reverse direction, the actuator drive output control circuit 50 first outputs a gate drive signal for the transistor T3B, and outputs a gate drive signal for the transistor T2 when a predetermined time has elapsed. Stop output.
[0031]
When regenerative braking is applied to the electric motor 30, the actuator drive output control circuit 50 outputs a gate drive signal to both the transistors T3A and T4A in a state where the output of the gate drive signal to the transistors T1 and T2 is stopped. Supply.
[0032]
FIG. 5 is a diagram showing a specific example of soft start, soft stop, and regenerative braking of the electric motor. FIG. 5A shows the magnitude and direction of the current supplied to the electric motor 30. FIGS. 5B to 5G show the operating states of the respective transistors.
[0033]
At time t1, transistors T1 and T4A are controlled to be conductive. Since the driving capability of the transistor T4A is 1/3 of that of the transistor T1, the current flowing through the motor is 1/3 of the rated current of 1.
[0034]
At time t2, the transistor T4B is controlled to be conductive, whereby the two transistors T4A and T4B connected in parallel are both conductive. Since the driving capability of the transistor T4B is 2/3 of that of the transistor T1, the motor current becomes the rated current when both the transistors T4A and T4B are turned on. As described above, when starting, one of the two transistors T4A and T4B connected in parallel is turned on first, and then the other is turned on, so that the motor current can be increased stepwise, and the soft start can be performed. It can be performed.
[0035]
When stopping the motor in the normal rotation state, the transistor T4B is turned off (time t3), and then the transistor T1 of the upper arm is turned off (time t4). As a result, the motor current can be gradually reduced, and a soft stop can be performed. The normal rotation drive period is from time t1 to time t4.
[0036]
The regenerative braking can be applied to the electric motor 30 by turning on the transistor T3A at time t4 and turning on both the transistor T3A and the transistor T4A of the lower arm.
[0037]
Here, the driving capability of each of the transistors T3A and T4A that are driven in the conductive state is as small as 1/3, so that the regenerative braking force is small. The regenerative braking force can be increased by driving both the transistors T3B and T4B in a conductive state instead of the transistors T3A and T4A. By driving all the transistors T3A, T3B, T4A, and T4B of the lower arm in a conductive state, the regenerative braking force can be further increased. Therefore, the regenerative braking system is achieved by bringing the transistors T3A and T4A into a conducting state, then bringing the transistors T3B and T4B into a conducting state, and finally putting all four transistors T3A, T3B, T4A and T4B into a conducting state. The power may be changed in three stages. By increasing the regenerative braking force in a stepwise manner, it is possible to prevent a sudden change in the rotation speed of the electric motor during regenerative braking and to prevent the motor from suddenly stopping. As a result, it is possible to reduce the backlash of the power transmission mechanism such as the reduction gear mechanism and the noise generated by the driven mechanism such as the door opening / closing mechanism during the regenerative braking.
[0038]
At time t5, both the transistors T3A and T4A are turned off to release the regenerative braking state.
[0039]
Next, the operation when the electric motor 30 is driven to rotate in the reverse direction will be described. At time t6, transistor T2 and transistor T3A are driven to a conductive state. Since the driving capability of the transistor T4A is 1/3 of that of the transistor T2, the current flowing through the motor becomes 1/3 of the rated current of 1.
[0040]
By turning on the transistor T3B at time t7, the two transistors T3A and T3B connected in parallel are both turned on. Since the driving capability of the transistor T3B is 2/3 of that of the transistor T2, the motor current becomes the rated current when both the transistors T3A and T3B are turned on. As described above, when starting, one of the two transistors T3A and T3B connected in parallel is turned on first, and then the other is turned on, so that the motor current can be increased stepwise, and the soft start can be performed. It can be performed.
[0041]
When stopping the electric motor 30 in the reverse rotation driving state, the transistor T3B is first turned off (time t8), and then the transistor T2 is turned off at time t9. As a result, the motor current can be gradually reduced, and soft stop is realized. After time t9, the electric motor 30 can be brought into a regenerative braking state by keeping both the transistor T3A and the transistor T4A conductive.
[0042]
FIG. 6 is a diagram illustrating another operation example of the soft start and the soft stop of the electric motor. FIG. 5 shows an example in which a step of reducing the motor current to 1/3 at the time of starting and stopping is shown. However, FIG. 6 shows a step of reducing the motor current to 2/3 at the time of starting and stopping. is there. When the motor is started in the normal rotation, the transistor T4B is turned on, and then the transistor T4A is turned on, so that the motor current can be increased stepwise from 0 → + 2/3 → + 1. When the motor is stopped, the transistor T4A is turned off first, and then the transistor T4B is turned off, whereby the motor current can be reduced stepwise from +1 to +2/3 to 0. When the motor is started in reverse rotation, the transistor T3B is turned on and then the transistor T3A is turned on, so that the motor current can be increased stepwise from 0 → −2 / 3 → −1. When the motor is stopped, the transistor T3A is turned off first, and then the transistor T3B is turned off, so that the motor current can be reduced stepwise from -1 to -2/3 to 0. it can.
[0043]
FIG. 7 is a diagram showing still another example of the operation of soft start and soft stop of the electric motor. Although FIGS. 5 and 6 show an example in which the motor current is changed in two stages, FIG. 7 shows an example in which the motor current is changed in three stages. When the motor is started by normal rotation, only the transistor T4A is turned on first, only the transistor T4B is turned on, and finally both the transistor T4A and the transistor T4B are turned on. Thus, the motor current can be increased in three stages from 0 → + 1/3 → + 2/3 → + 1. When the motor is stopped, only the transistor T4B is turned on, then only the transistor T4A is turned on, and finally both the transistors T4A and T4B are turned off. As a result, the motor current can be reduced in three stages: + 1 → + ２ → + ／ → 0. When the motor is driven in reverse, the motor current can be changed in three stages by driving the transistors T3A and 3B under the same conditions as described above.
[0044]
In the present embodiment, the transistors constituting the lower arm of the H-bridge circuit 51 are divided into two and connected in parallel, and the driving capability of each is reduced to 1/3, 2/3. May be set to 1/2 and 1/2. In this case, the driving capability of the motor can be switched between two stages, 1/2 and 2/2.
[0045]
The transistors forming the lower arm of the H-bridge circuit 51 may be divided into three and connected in parallel. For example, the motor is divided into three parts, and each of the driving capacities is set to 1/4, 1/4, 2/4. You can switch between stages.
[0046]
Further, in this embodiment, an example is shown in which an n-channel MOS field-effect transistor is used for each transistor constituting the H-bridge circuit 51. However, the transistor constituting the upper arm is a p-channel MOS field-effect transistor, The transistor forming the arm may be an n-channel MOS field effect transistor. Further, although the transistors T1, T2, T3A, T4A, T3B, T4B are integrated on the semiconductor chip 90, they need not necessarily be integrated, and may be constituted by individual transistor parts. Further, a transistor other than the field effect transistor may be used.
[0047]
【The invention's effect】
As described above, according to the present invention, the electric motor can be soft-started or soft-stopped, so that when the electric motor is started or stopped, a power transmission mechanism such as a reduction gear mechanism and a driven mechanism such as a door opening / closing mechanism are driven. Noise generated by the mechanism can be reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram conceptually showing a configuration of a main body of an automotive air conditioner to which a drive control device for an electric motor type actuator according to the present invention is applied.
FIG. 2 is a view showing a specific example of an electric motor type actuator according to the present invention.
FIG. 3 is a block diagram of a drive control device for an electric motor type actuator.
FIG. 4 is a circuit configuration diagram of an H-bridge circuit and its peripheral circuits.
FIG. 5 is a diagram showing a specific example of soft start, soft stop, and regenerative braking of the electric motor.
FIG. 6 is a diagram illustrating another operation example of soft start and soft stop of the electric motor.
FIG. 7 is a diagram showing still another operation example of soft start and soft stop of the electric motor.
FIG. 8 is a schematic diagram of a semiconductor chip having a built-in H-bridge circuit.
FIG. 9 is a circuit diagram of a conventional motor drive circuit having an H-bridge configuration.
[Explanation of symbols]
30 Electric motor 30A Electric motor type actuator 40 Control unit (drive control device for actuator)
50 Actuator drive output control circuit (drive control means)
51 H bridge circuit (driving means)
T1 Field Effect Transistor (Transistor)
T2 Field Effect Transistor (Transistor)
T3A field effect transistor (first parallel switching semiconductor device)
T3B field effect transistor (first parallel switching semiconductor device)
T4A field effect transistor (second parallel switching semiconductor device)
T4B field effect transistor (second parallel switching semiconductor device)

Claims (3)

Driving means for driving an actuator having an electric motor, and driving control means for controlling the driving means to control the rotation of the electric motor, wherein the driving means has an H-bridge circuit composed of a switching semiconductor element. A drive control device for an actuator,
One of the first switching semiconductor elements of the lower arm of the H-bridge circuit is composed of a plurality of first parallel switching semiconductor elements connected in parallel, and the sum of the respective capabilities of the first parallel switching semiconductor elements is determined by the first switching semiconductor element. The ability of the element
The other second switching semiconductor element of the lower arm is composed of a plurality of second parallel switching semiconductor elements connected in parallel, and the sum of the respective capabilities of the second parallel switching semiconductor element is defined as the capability of the second switching semiconductor element. ,
A drive control device for an actuator, wherein switching control of each of the first and second parallel switching semiconductor elements is individually performed. The H-bridge circuit is formed on one semiconductor chip, and forms a plurality of first and second parallel switching semiconductor elements connected in parallel within an area on the semiconductor chip on which the first and second switching semiconductor elements are formed. The drive control device for an actuator according to claim 1, wherein: The drive control means may be configured such that the total capability of each of the first and second parallel switching semiconductor elements increases stepwise, or the combination of the first and second parallel switching semiconductor elements reduces the total capability stepwise. 3. The drive control device for an actuator according to claim 1, wherein the switching control of the second parallel switching semiconductor element is performed.

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