JP2009050058A - Air conditioner for vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner for vehicles that makes it possible to enhance the accuracy of the stop position of a DC servo motor inexpensively. <P>SOLUTION: The air conditioner is so constructed that the following is implemented: the point at which power supply to a DC servo motor is cut according to supply voltage is varied based on the amount of inertia rotation at the time of servo stop according to the magnitude of voltage supplied to the DC servo motor; and the DC servo motor is thereby stopped at a point closer to a target position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioner, and more particularly to stop control of a DC servo motor of a vehicle air conditioner.

  The vehicle air conditioner is attached to most vehicles so that passengers can comfortably spend in the passenger compartment. When the occupant sets a preferred temperature, the air volume is adjusted based on the temperature detected by the temperature sensor installed in the passenger compartment and the set temperature, and the air outlet is selected.

  A DC servo motor is used for switching the air outlet, switching between outside air / inside air, adjusting the mixture of cold air / warm air, and adjusting the louver (which changes the air direction) at the air outlet. When the DC servo motor rotates and stops, the opening degree and position of the damper and louver for switching change. For the control of the DC servo motor, well-known PWM control is used, and the drive control of the DC servo motor is performed so as to stop at the target position based on the setting of the occupant.

  Even if energization to the DC servo motor is stopped to stop the DC servo motor at the target position, the motor may continue to rotate by inertia and may pass the target position. In this case, control is performed to reversely rotate the motor and return it to the target position. At this time, in order to prevent hunting of the motor by repeatedly passing the target position and reversing again, hysteresis (allowable range) may be provided at the target position, but there is a problem that the stop position accuracy is deteriorated.

  Therefore, when the servo motor approaches the target position, switching from DC drive that rotates / stops the servo motor by turning on / off the DC output to PWM drive that changes the DC output voltage step by step is performed. A servo motor drive control device has been devised that improves the stop position accuracy of the servo motor by decelerating the speed (see Patent Document 1).

JP 08-182366 A

  In the configuration of Patent Document 1, a circuit that performs PWM drive control is essential for the drive control unit of the DC motor. In other words, the microcomputer to be used must have PWM resources, or it must have enough processing power to handle the control that generates PWM signals by software and outputs them from the general-purpose output port in addition to the other controls to be processed. is there. Many recent microcomputers have PWM resources, but there are also many actuators that must be controlled using PWM signals. For example, in a vehicle air conditioner, dimming of a blower motor, solenoid valve, operation panel indicator LED, dimming of an LCD backlight, dimming of an operation knob illumination, and the like correspond. Depending on the microcomputer, there may be a shortage of PWM resources. In this case, a more sophisticated microcomputer must be employed, which increases the cost.

  Against the background of the above problems, an object is to provide a vehicle air conditioner that can improve the stop position accuracy when the DC servo motor is stopped at low cost.

Means for Solving the Problems and Effects of the Invention

  A vehicle air conditioner for solving the above-described problems sets drive means for energizing a DC servo motor to drive the DC servo motor, drive control means for controlling the drive means, and a stop designated position of the DC servo motor. Stop designation position setting means for performing, driving state detecting means for detecting the driving state of the DC servo motor, a data table for storing the inertial rotation amount of the DC servo motor corresponding to the detected various driving states, and set Based on the stop designated position and the inertial rotation amount, an energization cut-off position determining means for determining an energization cut-off position for cutting off the energization to the DC servo motor, a rotation position detection means for detecting the rotation position of the DC servo motor, Based on the detection result of the rotational position of the servo motor, position determining means for determining whether or not the energization cut-off position has arrived, and determining that the energization cut-off position has arrived. When the, characterized in that it comprises energizing interrupting control means for interrupting the power supply to the DC servo motor.

  With the above configuration, the DC servo motor is rotated / stopped by turning on / off the DC output by changing the point at which the power supply to the DC servo motor is cut based on the inertial rotation amount when the DC servo motor is stopped. Even when only the DC drive is used, the DC servo motor can be stopped at a point closer to the set stop designation position without performing complicated control.

  The drive state detection means in the vehicle air conditioner of the present invention includes drive voltage detection means for detecting a drive voltage supplied to the drive means, and the inertial rotation amount is determined based on the detected drive voltage. It can also be configured.

  The drive voltage supplied to the drive means of the vehicle air conditioner is supplied from a battery. Since the battery voltage varies depending on the usage state of the vehicle, the driving state of the DC servo motor also varies depending on the vehicle. With the above configuration, by using the inertial rotation amount corresponding to the driving voltage, the DC servo motor can be stopped at a point closer to the set stop designation position without performing complicated control.

  The DC servo motor in the vehicle air conditioner according to the present invention is used to drive at least one of an inside / outside air switching damper, an air mix damper, and an outlet switching damper, and drives each of the dampers. A data table may be stored corresponding to the DC servo motor.

  If these dampers are not switched accurately, the air-conditioning state differs from that set by the occupant, so that comfort is impaired and the occupant feels uncomfortable. With the above configuration, each damper can be switched accurately without performing complicated control, and comfort can be maintained.

  In addition, the drive control means in the vehicle air conditioner of the present invention is configured to continue the inertial rotation of the DC servo motor at the stop designated position after the power supply to the DC servo motor is cut off at the power cut-off position. It can also be configured.

  With the above configuration, PWM driving or control for switching from DC driving to PWM driving becomes unnecessary. Therefore, since it is not necessary to use a microcomputer having PWM resources, the cost of the vehicle air conditioner does not increase. Further, the drive control of the DC servo motor is not complicated, and the development period of the control program can be shortened.

  The vehicle air conditioner of the present invention can also be configured such that an allowable range in which the DC servo motor is normally stopped corresponding to the stop designated position is determined based on the inertial rotation amount.

  In order to stop the DC servo motor at the stop specified position, the energization cut-off position is determined in accordance with the inertial rotation amount. Therefore, the probability that the DC servo motor stops near the stop specified position is increased. With the above configuration, the allowable range (hysteresis) can be set to be equal to or smaller than the inertial rotation amount, for example. Further, since the stop position accuracy is increased, the allowable range can be reduced. Furthermore, since the frequency of overrun is reduced even if the allowable range is reduced, the frequency of occurrence of hunting is also reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an overall configuration of a vehicle air-conditioning control apparatus (hereinafter also referred to as an air conditioner) CA of the present invention. The vehicle air-conditioning control apparatus CA includes a duct 1, and an internal air intake port 13 for circulating the air inside the vehicle and an external air intake port 14 for taking in air outside the vehicle are formed in the duct 1. 15 is used by switching. Air from the inside air inlet 13 or the outside air inlet 14 is sucked into the duct 1 by a blower 16 driven by a blower motor 23.

  In the duct 1, there are an evaporator 17 for cooling the sucked air to generate cool air, and a heater core 2 (heating operation by waste heat of engine cooling water) that heats this to generate warm air. Is provided. And these cold air and warm air are mixed in the ratio corresponding to the angular position of the air mix damper 3, and it blows off from the blower outlets 4,5,6.

  Of these, the front glass anti-fog def outlet ([DEF]) 4 is located at the upper back of the instrument panel corresponding to the lower inner edge of the front glass, and the face ([FACE]) outlet 5 is located at the front center of the instrument panel. The foot outlets ([FOOT]) 6 are respectively opened at positions facing the passenger's feet at the back of the bottom of the instrument panel, and are individually opened and closed by the outlet switching dampers 7, 8, and 9. Specifically, according to the rotational input phase for damper control from the blower outlet switching motor 20, only the differential blower outlet 4 is opened by the damper drive gear mechanism 10, and only the face blower outlet 5 is opened. Only the foot outlet 6 is open, the face outlet 5 and the differential outlet 4 are open, the foot outlet 6 and the differential outlet 4 are open, the face outlet 5 and the differential outlet 4 , And the foot outlet 6 are all open.

  The inside / outside air switching damper 15 is electrically driven by an inside / outside air switching motor 21, the air mix damper 3 is driven by an air mix motor 19, and the outlet switching dampers 7, 8, 9 are electrically driven by an outlet switching motor 20. Is done. These motors 19, 20, and 21 are constituted by DC servo motors, and individual operations are centrally controlled by the air conditioner ECU 50 (see FIG. 2). Further, the blower motor 23 is composed of a brushless motor or the like, and the air flow rate is adjusted by the air conditioner ECU 50 by controlling the rotation speed by PWM control.

  The substance of the air conditioner ECU 50 is computer hardware including a well-known CPU, ROM, RAM, and the like, and includes an evaporator sensor 51, an inside air sensor 55, an outside air sensor 56, a water temperature sensor 57, a solar radiation sensor 58, an air volume setting switch 52, and an air outlet. A changeover switch 53, a temperature setting switch 54, an A / C switch 59, an inside / outside air changeover switch 60, an auto changeover switch 61, and a display 62 are connected.

  The air conditioner ECU 50 corresponds to drive control means, position determination means, energization cutoff control means, and energization cutoff position determination means of the present invention. Further, the air outlet changeover switch 53, the inside / outside air changeover switch 60, and the auto changeover switch 61 correspond to the stop designated position setting means of the present invention.

Specifically, the air conditioner ECU 50 performs the following control by executing an air conditioner control firmware mounted in a built-in ROM or the like (not shown).
Corresponding to the operation input state of the inside / outside air switching switch 60, the corresponding driver IC of the inside / outside air switching motor 21 so that the inside / outside air switching damper 15 is positioned at the inside air side, the outside air side, or a position between them. A drive control command is issued (see FIG. 2).
The operation of the evaporator 17 is turned on / off according to the operation state of the A / C switch 59.

Based on the input state of the auto changeover switch 61, the operation mode of the air conditioner is switched between the manual mode and the auto mode.
In the auto mode, referring to the input information of the set temperature by the temperature setting switch 54 and the output information of the inside air sensor 55, the outside air sensor 56, the water temperature sensor 57, and the solar radiation sensor 58, the in-vehicle temperature approaches the set temperature. Corresponding air mix motor 19, blower motor 23, air temperature adjustment by opening adjustment of air mix damper 3, air volume adjustment by blower motor 23, and position change of air outlet switching dampers 7, 8, 9 are made. An operation control command for the blower outlet switching motor 20 is issued.
In the manual mode, air volume adjustment by the blower motor 23 is performed in response to operation input states of the air volume setting switch 52 and the air outlet changeover switch 53, and the air outlet change dampers 7, 8, and 9 are in corresponding open / closed states. Thus, the drive control command to the blower outlet switching motor 20 is performed.

  The display 62 is configured as an LCD display, and displays various information related to the air conditioner such as the operating state of the air conditioner and the internal temperature.

  The drive control configuration of the DC servo motor will be described with reference to FIG. 2, taking the inside / outside air switching motor 21 (indicated as the servo motor assembly 210 in FIG. 2) as an example. The configurations of the air mix motor 19 and the air outlet switching motor 20 are the same. When a drive control command is sent from the CPU 501 of the air conditioner ECU 50 to the driver IC 213 by operating the inside / outside air changeover switch 60 or the like, the driver IC 213 turns the DC servo motor 211 on and off to rotate the DC servo motor 211. / Stop (DC drive). The driver IC 213 corresponds to the driving unit of the present invention and is included in the drive control unit 50a of FIG.

  The potentiometer 212 detects the operating state (rotational position) of the DC servo motor 211, that is, the position of the inside / outside air switching damper 15 as a voltage value, and the A / F of the CPU 501 via the input I / F (interface) 214. Output to the D conversion input terminal AD In. The CPU 501 A / D converts the input voltage value and uses it for drive control processing (described later).

  In the case of the inside / outside air switching motor 21, for example, when the inside / outside air switching damper 15 is in a state of completely closing the outside air suction port 14 (inside air circulation mode), the output voltage of the potentiometer 212 is the lowest. Has been. Then, as the DC servo motor 211 rotates, the output voltage of the potentiometer 212 increases as the inside / outside air switching damper 15 moves toward the inside air suction port 13, and the inside / outside air switching damper 15 moves the inside air suction port 13. It is configured such that the output voltage of the potentiometer 212 is the highest when it is completely closed (outside air introduction mode). The potentiometer 212 corresponds to the driving state detecting means and the rotational position detecting means of the present invention.

Further, unlike the conventional air conditioner ECU shown in FIG. 3, the air conditioner ECU 50 can detect the power supply voltage V _DD supplied to the driver IC 213. In general, the power supply voltage _{V DD} of the actuator such as a DC servo motor 211 is higher than the power supply voltage _{V CC} supplied to CPU501 like. Therefore, a power supply voltage measurement circuit 502 including resistors 502a and 502b is provided, and these resistors divide V _DD into values that can be input and A / D converted at the A / D conversion input terminal AD In of the CPU 501. The power supply voltage measuring circuit 502 corresponds to drive voltage detecting means of the present invention.

  The drive control processing of the DC servo motor (19, 20, 21) will be described with reference to FIG. This process is included in the air conditioner control firmware stored in the ROM or the like (not shown) of the air conditioner ECU 50, and is repeatedly executed along with other processes. First, switch information such as the air volume setting switch 52, the outlet switching switch 53, the temperature setting switch 54, the A / C switch 59, and the inside / outside air switching switch 60 is acquired (S10).

When there is a drive request for the DC servo motor (hereinafter abbreviated as servo motor) as described above based on the acquired switch information (S11: Yes), the power supply voltage V supplied to the driver IC by the power supply voltage measurement circuit. _DD is measured (S12). Then, the inertial rotation amount corresponding to the measured power supply voltage V _DD is read from the data table 50b (see FIG. 1) (S13).

FIG. 5 shows an example of the data table 50b. In the example of FIG. 5, the inertia rotation amount is set as a ratio to the total rotation amount of the servo motor, that is, the total movement amount of the damper, corresponding to the power supply voltage V _DD, that is, the battery voltage. V _DD = 10.0 ((V), for example the lower limit of the operating voltage range of the driver _{IC, V DD = 13.5 (V} ) is a standard output voltage value of the _battery, V DD = 16.0 ( V) is, for example, the maximum voltage value that can be supplied due to the battery specifications.

When the power supply voltage V _DD is other than the above value, the inertia rotation amount is obtained by linear interpolation, for example. Further, for example, the inertial rotation amount may be set in units of 0.5 (V) for the power supply voltage V _DD .

  The data table 50b is set for each servo motor (19, 20, 21). It may be set for each servo motor with a different rating. Alternatively, the load current (determined by the drive voltage) flowing through the servo motor may be detected by a known current sensor (for example, built in the driver IC), and the inertia rotation amount corresponding to the load current may be set as a data table. Alternatively, the rotational speed of the servo motor (determined by the drive voltage) may be detected by a known rotational sensor such as a resolver, and the inertial rotational amount corresponding to the rotational speed may be set as a data table.

Returning to FIG. 4, based on the read inertia rotation amount and the specified stop position of the damper obtained from the switch information, the energization interruption position for interrupting the energization to the servo motor is calculated by the following formula (S14).
Energization cutoff position = stop specified position-inertial rotation

  Next, a drive control command is sent from the CPU 501 to the driver IC of the servo motor to be driven, and the driver IC applies a drive voltage to the servo motor to start driving the servo motor (S15).

  Next, the current rotational position of the servo motor is detected by the potentiometer (S16). When the current rotational position of the servo motor reaches the energization cut-off position (S17: Yes), the CPU 501 sends a drive control command to the driver IC of the servo motor to be driven, and the driver IC sends the servo motor to the servo motor. The application of the driving voltage is stopped (S18).

  Thereafter, the servo motor continues inertial rotation and stops at or near the stop designated position.

  The details of the drive control processing will be described using FIG. 6 as an example of the inside / outside air switching motor 21 that moves the inside / outside air switching damper 15. The rotational position of the DC servo motor 211 detected by the potentiometer 212 is set to 0% when the inside / outside air switching damper 15 is in a state of completely closing the outside air suction port 14 (inside air circulation mode), and the inside / outside air switching damper 15 is set. Is 100% when the inside air inlet 13 is completely closed (outside air introduction mode) (corresponding to the absolute position in FIG. 6).

Here, when it is desired to move the inside / outside air switching damper 15 from the absolute position of 0% to 50% (inside / outside air mixing mode), the DC servo motor 211 is driven in the forward direction. At this time, the stop designation position is a position of 50 (%). Here, when the power supply voltage V _DD supplied to the driver IC is 13.5 (V), the inertial rotation amount B (%) is acquired with reference to the data table 50b. If B = 2 (%), the energization cut-off position is 50-2 = 48 (%). Therefore, when the current rotation position of the DC servo motor 211 is 48 (%), Application of the drive voltage to the DC servo motor 211 is stopped. Thereafter, the DC servo motor 211 continues the inertial rotation and stops at or near the position of 50 (%) which is the stop designated position.

  Here, an allowable positioning range (hysteresis width) of the DC servo motor 211 is determined. In the example of FIG. 6, when the DC servo motor 211 stops in the forward rotation direction and overruns beyond the position of 50 (%), for example, if it does not exceed the position of 54 (%), it stops at the stop designated position. If the position exceeds 54 (%), it is determined that the vehicle has not stopped at the stop designated position, and the drive control process described above drives the motor to stop at the stop designated position in the reverse direction. In the case of the reverse rotation direction, when the current rotation position of the DC servo motor 211 reaches 52 (%), the application of the drive voltage to the DC servo motor 211 is stopped. At this time, if the stop position does not exceed the 46 (%) position, it is determined that the vehicle has stopped at the specified stop position. If the stop position exceeds the 46 (%) position, it is determined that the stop has not been stopped at the specified stop position. It is driven again in the forward direction so as to stop within the position or tolerance.

  In addition, when the current rotation position of the DC servo motor 211 is 48% in the forward rotation direction, when the application of the drive voltage to the DC servo motor 211 is stopped, the DC servo motor 211 is If the vehicle stops at the position 48 (%), it is determined that the vehicle has not stopped at the stop designated position, and the drive control process is performed again.

The relationship between the power supply voltage V _DD and the hysteresis width will be supplementarily described with reference to FIG. In the prior art, taking into account fluctuations in the power supply voltage V _DD and setting the stop designation position as the reference (0%), a relatively wide range such as -A% to A% (double line) is set as the hysteresis width. Had to do. On the other hand, in the configuration of the present invention, the hysteresis width can be the same as or slightly larger than the inertial rotation amount.

For example, when the power supply voltage V _DD is relatively low, such as 10.0 (V), the inertial rotation amount becomes small. Therefore, the hysteresis width is indicated by a one-dot chain line with the stop designated position as a reference (0%) − A relatively narrow range such as D% to D% can be used. Even if the hysteresis width is narrowed in this way, the frequency of hunting does not increase because the inertial rotation amount is small. Similarly, when the power supply voltage V _DD is intermediate (-C% to C%: solid line) and relatively high (-B% to B%: broken line), the hysteresis width is set to a range corresponding to the inertial rotation amount. can do. Thereby, the positioning accuracy when the DC servo motor is stopped can be improved.

As described above, the hysteresis width does not exceed the range of -B% to B%, and the upper limit value of the hysteresis width can be set smaller than the conventional value based on the inertial rotation amount. Further, when the variation in inertia rotation amount is small in the vehicle air conditioning control device, the hysteresis width can be made smaller than the inertia rotation amount. For example, when the power supply voltage V _DD is relatively high, the deviation between the stop designation position (0% position) and the actual stop position is B even if the energization cut-off position is B% (or -B%). If it is within / 2%, the hysteresis width can be -B / 2% to B / 2%.

  Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited to these embodiments, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

The figure which shows the structure of the vehicle air conditioner control apparatus. The figure which shows the structure of the drive control of a DC servomotor by this invention. The figure which shows the structure of the drive control of a DC servomotor by a prior art. The flowchart explaining the drive control processing of a DC servomotor. The figure which shows an example of a data table. The figure explaining the detail of a drive control process. The figure explaining the relationship between a power supply voltage and a hysteresis width.

Explanation of symbols

3 Air Mix Damper 7, 8, 9 Blower outlet damper 15 Inside / outside air damper 19 Air Mix Motor (DC Servo Motor)
20 Air outlet switching motor (DC servo motor)
21 Inside / outside air switching motor (DC servo motor)
50 Air conditioner ECU (drive control means, position determination means, energization interruption control means stage, energization interruption position determination means)
50a Drive control unit 50b Data table 53 Outlet switch (stop designated position setting means)
60 Inside / outside air changeover switch (stop specified position setting means)
61 Auto changeover switch (stop specified position setting means)
211 DC servo motor 212 Potentiometer (driving state detecting means, rotational position detecting means)
213 Driver IC (driving means)
501 CPU
502 Power supply voltage measurement circuit (drive voltage detection means)
CA vehicle air conditioning controller

Claims (5)

Drive means for energizing the DC servo motor to drive the DC servo motor;
Drive control means for controlling the drive means;
Stop designation position setting means for setting a stop designation position of the DC servo motor;
Driving state detecting means for detecting a driving state of the DC servo motor;
A data table for storing the inertial rotation amount of the DC servo motor corresponding to various detected driving states;
An energization interruption position determination means for determining an energization interruption position for interrupting energization to the DC servo motor based on the set stop designation position and the inertial rotation amount;
Rotational position detecting means for detecting the rotational position of the DC servo motor;
Position determining means for determining whether or not the energization cut-off position has arrived based on the rotation position detection result of the DC servo motor;
When it is determined that the energization cut-off position has arrived, energization cut-off control means for cutting off energization to the DC servo motor;
A vehicle air conditioner comprising: The drive state detection means includes drive voltage detection means for detecting a drive voltage supplied to the drive means,
The vehicle air conditioner according to claim 1, wherein the inertial rotation amount is determined based on the detected drive voltage.   The DC servo motor is used to drive at least one of an inside / outside air switching damper, an air mix damper, and an outlet switching damper, and corresponds to the DC servo motor that drives each of the dampers. The vehicle air conditioner according to claim 1 or 2, wherein the data table is stored.   4. The drive control means continues the inertial rotation of the DC servo motor at the stop designated position after the energization to the DC servo motor is cut off at the energization cut-off position. The vehicle air conditioner according to any one of the above.   The vehicle according to any one of claims 1 to 4, wherein an allowable range in which it is determined that the DC servo motor has normally stopped corresponding to the stop designated position is determined based on the inertial rotation amount. Air conditioner.

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