JP2006273007A - Circuit abnormality diagnosis device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit abnormality diagnosis device capable of performing abnormality diagnosis of a potentiometer. <P>SOLUTION: The circuit abnormality diagnosis device has an air mix door actuator 43 driven according to an indication signal, the potentiometer 45 which is provided on the air mix door actuator 43 and outputs the detection signal corresponding to the position of a driving member, and an abnormality determination means 53 performing the abnormality diagnosis based on the detection signal. The relationship between an indication value indicated by the indication signal and a detection value indicated by the detection signal is set so that the indication value covers the unused area where the potentiometer exceeds the value of the practical area that is actually used for detection, an the abnormality determination means 53 determines that is abnormal when the detection value indicates the unused area. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a circuit abnormality diagnosis device for diagnosing a circuit abnormality including a potentiometer in an apparatus including an actuator incorporating a potentiometer such as a vehicle air conditioner.

  Conventionally, it is known that control accuracy is improved by controlling a target drive value and an actual drive value to coincide with each other by an actuator incorporating a potentiometer.

  For example, in an automotive air conditioner, it is known that such actuators and controls are used for drive control of intake doors, air mix doors, and the like, and the actual opening of each door is feedback controlled based on a detection signal of a potentiometer. Yes.

Furthermore, it is also known that in such a device, it is diagnosed whether the actuator is operating normally without causing problems such as motor lock (for example, see Patent Document 1).
JP-A-10-138742

  However, the prior art does not have a configuration for determining a circuit abnormality including a potentiometer and cannot detect the circuit abnormality.

  Accordingly, an object of the present invention is to provide a circuit abnormality diagnosis device that can perform abnormality diagnosis of a potentiometer.

The present invention has been made in view of the above circumstances, and includes an actuator that is driven in response to an instruction signal, a potentiometer that is provided in the actuator and outputs a detection signal corresponding to the position of the driving member, and the detection signal. An abnormality determination means for making an abnormality determination based on,
The relationship between the indication value indicated by the indication signal and the detection value indicated by the detection signal covers the unused range where the indication value exceeds the practical range value that the potentiometer actually uses for detecting the position of the drive member. Set to
The abnormality determination unit is a circuit abnormality diagnosis device whose main feature is that an abnormality is determined when the detected value indicates the unused area.

The invention according to claim 2 is the circuit abnormality diagnosis device according to claim 1,
The abnormality determining means determines that a short circuit occurs when the detected value is smaller than a value corresponding to the practical range, and an open state when the detected value is larger than a value corresponding to the practical range.

The invention according to claim 3 is the circuit abnormality diagnosis device according to claim 2,
In the allocation of the indicated value and the detected value, 5% to 95% of the entire range of 0 to 100% of the indicated value is allocated to the practical area and less than 5% and more than 95% are allocated. Allocate to the unused area,
The abnormality judging means judges that the detection value is short when the value corresponding to the unused area of less than 5% is present, and is open when the value corresponding to the unused area exceeding 95% is indicated. It is characterized by.

The invention according to claim 4 is the circuit abnormality diagnosis device according to any one of claims 1 to 3,
A pull-up resistor for setting the detection signal to a high level is provided at a portion where the detection signal of the potentiometer is input.

The invention according to claim 5 is the circuit abnormality diagnosis device according to claim 4,
The actuator is an actuator that drives a door that controls the flow of air in an in-vehicle air conditioner,
The abnormality determination means is provided in a control unit that controls the operation of the air conditioner.

  According to the present invention, since the instruction value input to the actuator and the detected value of the potentiometer are set to cover the unused area of the potentiometer, the unused area that should not be output from the potentiometer. When a detection value corresponding to the instruction value is input, an abnormality can be diagnosed.

  Thus, in the present invention, it is possible to detect a circuit abnormality including a potentiometer. Moreover, this circuit abnormality can be detected based on the detected value only by setting the allocation of the indicated value and the detected value as in the present invention, and can be controlled without changing the configuration on the potentiometer side. It can be handled only on the side, which is advantageous in terms of cost and excellent in versatility.

  In the invention of claim 2, when diagnosing an abnormality, it is further determined that if the detected value is smaller than the value corresponding to the practical range, short, open if the value is larger than the value corresponding to the practical range, The details of whether the circuit abnormality is short or open can be seen.

  In the invention according to claim 3, when the detected value indicates a value corresponding to an unused area less than 5% of the indicated value, a short occurs, and when a value corresponding to an unused area exceeding 95% of the indicated value is indicated. Judged to be open. In this way, by setting the unused area up and down 5%, the actuator control accuracy is higher than when the unused area is expanded, and the abnormality detection accuracy is higher than when the unused area is narrower than this. Therefore, it is possible to achieve both the control accuracy of the actuator and the abnormality detection accuracy.

  According to the fourth aspect of the present invention, the detection value of the potentiometer is raised to a high level by the pull-up resistor, and the abnormality determination can be performed more reliably.

  According to the fifth aspect of the present invention, in the in-vehicle air conditioner, it is possible to detect the circuit abnormality of the potentiometer provided in the actuator that drives the door by the abnormality determining means provided in the control unit.

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

  FIG. 2 is an overall configuration diagram showing an air conditioner A to which the circuit abnormality diagnosis device according to the embodiment of the present invention is applied.

  First, the configuration of the air conditioner A will be described.

  This air conditioner A has an air conditioning unit 100 in which an intake unit 10, a cooler unit 20, and a heater unit 30 are connected in order.

  The intake unit 10 is a unit that takes air outside the vehicle interior into the air conditioning unit 100, and an intake air case 12 for taking air outside the vehicle interior into the intake unit case 11 constituting the outer shell of the intake unit 10. And an indoor air inlet 13 for circulating the room air.

  Further, the intake unit case 11 is provided with a fan 15 that is rotated by a fan motor 14 that takes in air, and an intake door 16D that changes the ratio of the inside and outside air to be taken in.

  The intake door 16D is configured to rotate between the position where the outside air inlet 12 is fully closed (inside air circulation mode) and the position where the inside air inlet 13 is fully closed (outside air intake mode). The rotation of the intake door 16D is performed by an intake door actuator 41 that is also attached to the intake unit case 11.

  The cooler unit 20 includes a cooler unit case 21 constituting an outer shell of the cooler unit 20 and an evaporator (condenser) for cooling the intake air installed in the cooler unit case 21 across the flow path. 22.

  The heater unit 30 functions to regulate the temperature of the air that has passed through the intake unit 10 and the cooler unit 20 and distribute conditioned air from a desired outlet to the vehicle interior. For this purpose, the heater unit case 31 forming the outer shell of the heater unit 30 is provided with a heater core 32 so as to form a bypass path 37, and the air mix door 33D provided on the front surface of the heater core 32 is used to The ratio between the amount of air passing through the heater core 32 and the amount of air passing through the bypass passage 37 is adjusted.

  The engine cooling water of the vehicle circulates in the heater core 32, and the intake air is heated by heat exchange between the engine cooling water and air. The air mix door 33D rotates between a position where the front surface of the heater core 32 is fully closed (full cool) and a position where the bypass path 37 is fully closed (full hot) by driving the air mix door actuator 43. Move.

  An air mix chamber 39 is formed on the downstream side of the heater unit case 31, and a vent outlet 34, a defrost outlet 35 and a foot outlet 36 are formed therein. The vent outlet 34 communicates with a vent grill provided on the front surface of the instrument panel in the passenger compartment through an air duct (not shown), and blows out conditioned air mainly toward the upper body of the occupant. The defrost outlet 35 communicates with a defrost grill provided on the upper surface of the instrument panel through an air duct (not shown), and blows out low-humidity air or hot air toward the inner surface of the windshield to clear the cloudy weather. The foot outlet 36 opens from the heater unit case 31 directly or through a short air duct at the foot of the passenger in the passenger compartment, and mainly blows warm air toward the feet of the passenger.

  In addition, a vent door 34D, a differential door 35D, and a foot door 36D are provided at the air outlets 34, 35, and 36, respectively, so that the air outlets can be opened and closed. These doors 34D, 35D, and 36D are provided with a link mechanism or the like. Via the mode door actuator 44. That is, these doors operate according to combinations of opening and closing of the three doors 34D, 35D, and 36D by selecting various blowing modes such as a vent mode, a defrost mode, a bi-level mode, and a foot mode. For example, in the bi-level mode, the vent air outlet 34 and the foot air outlet 36 are respectively opened half way, cold air is blown out from the vent air outlet 34, and warm air is blown out from the foot air outlet 36, so-called head cold foot heat type temperature control is performed. .

  Further, in the air conditioning unit 100 of the present embodiment, a second bypass path 38 is formed in the heater unit case 31, and a bypass door 38D that fully closes and fully opens the second bypass path 38 is provided. The bypass door 38D is operated by the bypass door actuator 42. When the air mix door 33D is rotated to the fully open position to guide the warm air to the foot outlet 36, the bypass door 38D is fully opened, Is led to the vent outlet 34, thereby increasing the temperature difference in the thermal head temperature control.

  Next, the configuration of the control system of the air conditioner A will be described.

  The air conditioner A includes an air conditioner control unit (hereinafter referred to as an AC control unit) 50, various sensors 61 to 66, and a control panel 70.

  The AC control unit 50 has a built-in microcomputer, and performs arithmetic processing on input signals from various sensors 61 to 66 (described later) and switches of the control panel 70 in accordance with program software, and the fan motor 14 and door actuators 41 to 41 are processed. 44 and the compressor etc. outside the figure are comprehensively controlled.

  The sensors include a water temperature sensor 61 that detects the engine coolant temperature, a refrigerant temperature sensor 62 that detects the temperature of the refrigerant circulating in the cooling cycle, an inside air sensor 63 that detects the actual air temperature inside the vehicle interior, and an actual outside of the vehicle interior. An outside air sensor 64 for detecting the air temperature of the air, a solar radiation sensor 65 for detecting the amount of solar radiation entering the room from the windshield (not shown), and a suction temperature sensor 66 for detecting the air temperature after passing through the evaporator 22 are provided. .

  The control panel 70 is mounted at the center of an instrument panel that is easy for the passenger to operate, and includes various switches 71 such as a fan switch, a balance control lever (or dial), a blowing mode switch, an air conditioner switch, and a forced air circulation switch. And a display panel 72 for displaying fan speed, temperature, and the like, and a communication interface 73 for performing data communication with the AC control unit 50.

  In the present embodiment, a circuit abnormality diagnosis device is applied to the air mix door actuator 43.

  First, an outline of control of the air mix door 33D in the AC control unit 50 will be described.

  As described above, the air mix door 33D adjusts the ratio of the amount of air that passes through the heater core 32 and the amount of air that passes through the bypass path 37. The blowing air temperature can be determined.

  FIG. 1 is a block diagram schematically showing a portion for controlling the opening degree of the air mix door 33D in the AC control unit 50. In the target door opening degree determining means 51, the switches 71 and the sensors 63 to 66 are shown. From the set temperature, the inside air temperature, the outside air temperature, the amount of solar radiation, and the suction temperature set by the occupant, and obtain the temperature deviation between the set temperature and the room temperature taking into account the temperature-influencing factors. A degree is determined, and control is performed to output an instruction signal corresponding to the target opening to the air mix door actuator 43.

  Next, the configuration of the air mix door actuator 43 will be described.

  As shown in FIG. 3, which shows a main part of the air mix door actuator 43, the air mix door actuator 43 includes an electric motor 43 a and a worm 43 c attached to an output shaft 43 b of the electric motor 43 a. A reduction gear train mechanism 43d that engages with the worm 43c and transmits rotation while decelerating, and an actuator lever that is coupled to the output gear 43e of the reduction gear train mechanism 43d and rotates integrally with the output gear 43e. 43f. Then, the rotation of the actuator lever 43f is transmitted via a link mechanism (not shown) to rotate the air mix door 33D.

  The air mix door actuator 43 is provided with a potentiometer 45 for outputting a signal indicating the position, that is, the angle of the actuator lever 43f. The potentiometer 45 includes a resistor 45a having a predetermined length and a moving contact 45b that moves on the resistor 45a. The potentiometer 45 changes the resistance value according to the change in the contact position of the moving contact 45b. A voltage detection signal corresponding to the position of the actuator lever 43f is output.

  The resistor 45a of the potentiometer 45 is concentric with the output gear 43e, and is formed in a concave shape on the base 43g of the air mix door actuator 43 as shown in FIG. 4, which is a cross-sectional view taken along line S4-S4 of FIG. The arc grooves 43h are provided along the bottom surface of the arc groove 43h, and both ends thereof are electrically connected to a circuit (not shown) by solder or the like at positions protruding from the side edges of the arc groove 43h to the surface of the base body 43g. Yes.

  The moving contact 45b is a brush or the like provided so as to protrude from the back surface of the output gear 43e at a position overlapping with the actuator lever 43f, and is inserted into the arcuate groove 43h to be in contact with the resistor 45a.

  Therefore, in the potentiometer 45, the full strokes of the actuator lever 43f and the output gear 43e are determined by the arc groove 43h and the moving contact 45b. That is, the movement of the moving contact 45b is mechanically restricted at a position where it abuts against both end faces of the arc groove 43h, whereby the full stroke of the potentiometer 45 is determined.

  In the present embodiment, the full stroke (angle from fully open to fully closed) of the air mix door 33D is also made to coincide with the full stroke of the potentiometer 45, and the potentiometer 45 actually serves as a drive member. The practical range used for detecting the position of the actuator lever 43f coincides with the full stroke of the potentiometer 45. As an example of the angle of the full stroke, in the present embodiment, the angle is 0 to 105 °.

  Therefore, in the present embodiment, in the resistor 45a, a portion that is disposed at the bottom of the circular arc groove 43h and contacts the moving contact 45b in the practical area (= full stroke area) is defined as a practical part 45c. Therefore, a portion that is disposed outside the arc groove 43h and does not contact the moving contact 45b is referred to as an extension 45d.

  Further, in the present embodiment, as shown in FIG. 5, a pull-up resistor 52 is provided at a portion where the detection signal of the potentiometer 45 is input in the AC control unit 50 so as to raise the voltage value of the detection signal. I have to.

  Next, the relationship between the instruction signal output from the AC control unit 50 to the air mix door actuator 43 and the detection signal from the potentiometer 45 will be described.

  When the AC control unit outputs an instruction signal indicating the target opening, the actual opening matches the target door opening based on the lever angle corresponding to the actual door opening indicated by the detection signal of the potentiometer 45. Feedback control is performed.

  Therefore, in order to perform this feedback control, it is necessary to associate the instruction value indicated by the instruction signal with the detection value indicated by the detection signal. In this correspondence (allocation), in the present embodiment, the indicated value is set to cover an unused area exceeding the practical area of the potentiometer 45.

  That is, in the present embodiment, the instruction value (instruction opening) is formed by a 256-bit signal. Of this instruction value, as shown in the characteristic diagram of FIG. Allocation is made so as to correspond to the lever angle in the practical range (full stroke range) of the potentiometer 45, and the range below 0% and over 95% of the indicated value is the unused range outside the practical range (full stroke range) of the potentiometer 45 Is set to cover.

  FIG. 8 is an explanatory diagram showing the relationship between the allocation of the indicated value and the resistor 45a and full stroke of the potentiometer 45. As shown in this figure, with respect to 105 ° which is the full stroke of the potentiometer 45, FIG. The indicated values of 16 bits to 239 bits are allocated. The indicated values of 0 to 16 bits and 239 to 255 bits are allocated to unused areas outside the practical area corresponding to the practical part 45c of the resistor 45a. In addition, in the resistor 45a shown in FIG. 8, a white portion indicates a carbon resistance pattern portion having a high resistance value, and a hatched portion indicates a portion in which the silver pattern is applied to the base to reduce the resistance value. In FIG. 8, a contact point 45f provided on the inner peripheral side of the resistor 45a is connected to the moving contact point 45b and is connected to an output part (VPBR) of the potentiometer 45.

  As described above, the values in the region of less than 0% and exceeding 95% of the indicated value correspond to the unused region in which the air mix door 33D cannot actually be moved to this position. Does not actually output the indicated value in this area, and uses a signal of 5 to 95% of the indicated value, that is, a signal of 16 bits to 239 bits, as a signal indicating the target opening.

  Incidentally, in the past, the indicated value and the practical range of the potentiometer are assigned on a one-to-one basis, that is, in the characteristic diagram of FIG. 6, 0 bit of the indicated value is 0% lever angle (fully closed: 0 °). ), The indicated value of 256 bits corresponds to 100% of the lever angle (fully open: 105 °). On the other hand, in the present embodiment, allocation is made so that the vicinity of the indicated value of 12 bits is 0% of the lever angle (fully closed: 0 °) and the vicinity of the indicated value of 243 bits is 100% of the lever angle (fully opened: 105 °). Yes.

  Further, in the present embodiment, as shown in FIG. 1, the AC control unit 50 is provided with an abnormality determination means 53 for diagnosing a circuit abnormality of the potentiometer 45. In this abnormality determination means 53, when the detection signal (detection value) from the potentiometer 45 shows a value corresponding to an unused area exceeding the practical area (full stroke area) of 5 to 95%. Judged as abnormal. That is, as shown in the flowchart of FIG. 7, it is determined whether or not the detected value Vpt is less than 5% (Vmin), which is the minimum practical range (step S1). On the other hand, it is determined whether the detected value Vpt exceeds 95% (Vmax) of the practical range maximum (step S3). If YES, it is determined that the detection value Vpt is open (disconnected) (step S4).

  That is, in the present embodiment, since the indication value of the unused area is not output, if a detection value corresponding to the unused area that should not be detected is input, it is determined as abnormal. To do.

  The potentiometer 45 has extension portions 45d and 45d for circuit connection at both ends of the resistor 45a. For this reason, in the circuit connected to the potentiometer 45, the voltage (detected value Vpt) when a short circuit occurs is surely smaller than the value of 5% (Vmin), which is the minimum practical range, and is open. When this occurs, the voltage (detected value Vpt) is surely a larger value than the maximum value of 95% (Vmax) in the practical range. However, these extension portions 45d and 45d need only differ from the values of 5% and 95% by their presence, and correspond to 0 to 5% and 95 to 100% of the above indicated values. Well not.

  Further, such an abnormal value is caused not only by short / open but also in the potentiometer 45, due to an abnormal operation of the actuator lever 43f or the output gear 43e, the moving contact 45b comes out of the arc groove 43h to the extension 45d. It also appears when the vehicle contacts or moves away from the resistor 45a. Also in these cases, the abnormality can be detected by the determination of the short circuit or the open circuit.

  When an abnormality is determined, the display is performed on the display panel 72 provided on the control panel 70, and the AC control unit 50 performs control corresponding to the abnormality.

As described above, the present embodiment has the effects listed below.
a) An abnormality diagnosis of the potentiometer 45 can be performed.
Furthermore, when performing this abnormality diagnosis, the indication value is not allocated to the practical range (full stroke range) as in the past, but the indication value is assigned to the unused range outside the practical range. It is possible to detect an abnormality in the AC control unit 50 only by setting to cover the air, and it is not necessary to change the actuator side which is the air mix door actuator 43, and an existing one can be used, which is advantageous in terms of cost. And versatility.

  Note that the extension 45d in the resistor 45a has an existing configuration and is not provided for the implementation of the present invention.

  b) In abnormality determination, short / open determination can be performed, and the abnormality can be known in detail. Furthermore, it is possible to simultaneously detect the moving contact 45b on the potentiometer 45 and a connection failure.

  c) Since the pull-up resistor 52 is provided in the portion where the signal from the potentiometer 45 is input and the detection signal is raised, the abnormality determination accuracy is increased.

  d) Since the potentiometer 45 uses the full stroke region as a practical region used for detection, the control accuracy can be increased.

  e) By making 5 to 95% of the indicated value correspond to the practical range of the potentiometer, it is possible to perform feedback control with higher accuracy than when the unused range is widened. Abnormality determination can be performed more reliably than when narrower than this, and both control accuracy and abnormality determination accuracy can be achieved.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to this embodiment. Included in the invention.

  In other words, in the embodiment, the air mix door actuator 43 is used as the actuator. However, the actuator can be applied to other actuators such as the intake door actuator 41, as long as it is an actuator having a potentiometer. It can also be applied to devices other than the air conditioners shown.

  Further, in the embodiment, as an example of the relationship between the instruction value and the detection value, the practical area is set to a range of 5 to 95% of the instruction value, and less than 5% and more than 95% is set to the unused area. This numerical value is not limited to this, and the unused area may be a value smaller than 5% or vice versa, and similarly, a value larger than 95% or a smaller value may be used. .

  In the embodiment, the full stroke of the potentiometer is used as a practical range. However, this practical range may be set to a range narrower than the full stroke.

It is a block diagram which shows typically the part which performs the opening degree control of an air mix door in the air-conditioner control unit which has the circuit abnormality diagnostic apparatus of embodiment of this invention. It is a whole lineblock diagram showing an air-conditioning device to which a circuit abnormality diagnostic device of an embodiment of the invention is applied. It is explanatory drawing which shows the principal part of the air mix door actuator in embodiment of this invention. It is sectional drawing which shows the principal part of the potentiometer used for embodiment of this invention, Comprising: It is sectional drawing by the S4-S4 line | wire of FIG. It is a circuit diagram which shows the input part of the potentiometer in the air-conditioner control unit of embodiment of this invention. It is a characteristic view which shows the relationship between the instruction | indication value and lever angle in embodiment of this invention. It is a flowchart which shows the flow of abnormality determination in embodiment of this invention. It is explanatory drawing which shows the relationship between the allocation of the instruction | indication value in the embodiment of this invention, the resistor 45a of the potentiometer 45, and a full stroke.

Explanation of symbols

43 Air mix door actuator 43f Actuator lever (drive member)
45 Potentiometer 50 Air-conditioner control unit 52 Pull-up resistor 53 Abnormality judging means A Air-conditioner

Claims (5)

An actuator driven in response to the instruction signal;
A potentiometer that is provided in the actuator and outputs a detection signal corresponding to the position of the driving member;
An abnormality determination means for performing an abnormality determination based on the detection signal;
Have
The relationship between the indication value indicated by the indication signal and the detection value indicated by the detection signal is an unused range in which the indication value exceeds a practical range value that the potentiometer actually uses for detecting the position of the driving member. Set to cover,
The circuit abnormality diagnosing apparatus according to claim 1, wherein the abnormality determining unit determines that an abnormality occurs when the detected value indicates the unused area. 2. The abnormality determination unit determines that the detection value is short when the detection value is smaller than a value corresponding to the practical range, and is open when the detection value is larger than a value corresponding to the practical range. The circuit abnormality diagnosis device described. In the allocation of the indicated value and the detected value, 5% to 95% of the entire range of 0 to 100% of the indicated value is allocated to the practical area and less than 5% and more than 95% are allocated. Allocate to the unused area,
The abnormality determining means determines that the detection value is short when the value corresponding to the unused area of less than 5% is present, and is open when the value corresponding to the unused area exceeding 95% is indicated. The circuit abnormality diagnosis device according to claim 2. The circuit abnormality diagnosis apparatus according to claim 1, wherein a pull-up resistor that raises the detection signal to a high level is provided at a portion where the detection signal of the potentiometer is input. The actuator is an actuator that drives a door that controls the flow of air in an in-vehicle air conditioner,
The circuit abnormality diagnosis device according to claim 1, wherein the abnormality determination unit is provided in a control unit that controls the operation of the air conditioner.

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