JP2006113025A - Temperature measuring device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature measuring device of a vehicle capable of precisely measuring an absolute temperature distribution in a vehicle compartment even if disturbance light affects and thereby precisely measuring a surface temperature of a human, and therewith precisely estimating a distance from an air outlet of air conditioning to the human, to perform a comfortable air-conditioning control. <P>SOLUTION: The temperature measuring device 1 of a vehicle comprises an infrared sensor unit 2 for detecting infrared light emitted by a thermopile module 21 with 16 elements in a vehicle compartment to measure a temperature with a distribution, wherein the CPU 24 of the infrared sensor unit 2 performs the calibration of the thermopile module 21 from a standard heater unit 3 heating at a predetermined temperature and the detected results of the standard heater unit 3 by the thermopile module 21 in an objective range to be detected of the thermopile module 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention belongs to the technical field of a vehicle temperature measuring device that measures the temperature inside a vehicle mainly for a vehicle air conditioner.

  2. Description of the Related Art Conventionally, in order to make air conditioning more comfortable in a vehicle air conditioning system, a plurality of infrared sensors or one or two-dimensional infrared sensor arrays arranged in a passenger compartment can be used for human skin, clothing, and its surroundings. The surface temperature is measured in a non-contact manner, the position of a person is estimated from the temperature distribution, and the air-conditioning blowout temperature, air volume, and wind direction are controlled (see, for example, Patent Document 1).

Also, the distance from the air-conditioning outlet to the person is estimated based on the temperature distribution, the air volume and direction are controlled, the distance from the airbag to the person is estimated, and the presence / absence of the operation of the airbag and the deployment speed are controlled. Has been proposed (see, for example, Patent Document 2).
JP-A-4-271912 (page 2-5, full view) Japanese Patent Laid-Open No. 11-201822 (page 2-5, full view)

  However, conventionally, it is practical to use a thermal infrared sensor from the viewpoint of cost in order to actually measure the temperature distribution in the passenger compartment by using an infrared sensor. The thermal sensor has low sensitivity and a weak output signal. For this reason, the output signal is amplified by several tens of thousands of times and used, and it is practically difficult to measure the absolute temperature with high accuracy because it is easily affected by noise. For example, it is conceivable that a measurement error occurs due to a disturbance entering the vehicle interior. When an infrared sensor is used for air conditioning control, it has been required to measure the temperature distribution of a person and its surroundings to estimate the position of the person and to measure the absolute temperature as accurately as possible.

  The present invention has been made paying attention to the above-mentioned problems, and the object of the present invention is to accurately measure the absolute temperature distribution in the passenger compartment even when there is an influence of ambient light. Is to accurately estimate the distance from the air-conditioning outlet to the person, and to provide a more comfortable air-conditioning control.

  In order to achieve the above object, according to the present invention, in the vehicle temperature measuring apparatus, the infrared sensor includes an infrared sensor that detects infrared light radiated in the vehicle interior by a plurality of elements and measures the temperature in a distribution. And a means for calibrating the infrared sensor from the detection result of the standard heating element by the infrared sensor.

  Therefore, in the present invention, the absolute temperature distribution in the passenger compartment can be accurately measured even when there is an influence of disturbance light. Thereby, while measuring the surface temperature of a passenger | crew correctly, the distance from the blower outlet of an air conditioning to a passenger | crew can be estimated more correctly, and more comfortable air-conditioning control can be performed.

  Hereinafter, an embodiment for realizing a vehicle temperature measuring device of the present invention will be described based on Example 1 corresponding to the invention according to claims 1, 2, 3, and 4.

First, the configuration will be described.
FIG. 1 is a schematic diagram of a vehicle temperature measuring apparatus according to a first embodiment. FIG. 2 is a block diagram of the vehicle temperature measuring apparatus according to the first embodiment.
The vehicle temperature measuring apparatus 1 according to the first embodiment includes an infrared sensor unit 2 and a standard heating element unit 3 as main components, and the infrared sensor unit 22 is connected to the air conditioning control unit 4 of the vehicle.
The infrared sensor unit 2 has a thermopile module 21, an analog filter 22, a visible light sensor 23, a CPU 24 (corresponding to calibration means), an A / D converter 25, and a communication I / F 26 as main components.
The thermopile module 21 incorporates a thermopile element temperature measurement thermistor, multiplexer, amplifier, and amplifier reference voltage output circuit that measures the temperature by dividing the visual field range into 16 one-dimensional directions.

The analog filter 22 is a filter circuit that reduces noise in output signals of the thermopile module 21 and the visible light sensor 23.
The visible light sensor 23 monitors the state of disturbance light during calibration.
The A / D converter 25 A / D converts the output signals of the thermopile module 21 and the visible light sensor 23 and outputs the result to the CPU 24.
The CPU 24 communicates with the standard heating element unit 3 to generate heat for calibration, calibrates from the infrared light image of the standard heating element unit 3 and the detection result of the visible light sensor 23, and based on the calibration result, the vehicle 24 The room temperature is measured, and the result is transmitted to the air conditioning control unit 4 via the communication I / F 26.
The communication I / F 26 inputs and outputs data with the outside.

The standard heating element unit 3 includes a CPU 31 (corresponding to heat generation temperature changing means and chopping means), a heater 32, a temperature sensor 33 (corresponding to vehicle interior atmosphere temperature detecting means), an A / D converter 34, a shutter opening / closing device 35, The communication I / F 36 is the main component.
The CPU 31 controls the start and end of heat generation through communication with the infrared sensor unit 2, and controls the heater 32 and the shutter opening / closing device 35 based on the detection result of the temperature sensor 33.
The heater 32 generates heat so as to radiate infrared light toward the vehicle interior and the thermopile module 21 provided in the vehicle interior. The amount of heat generated by the heater 32 is controlled by the CPU 31.

The temperature sensor 33 is provided on the substrate of the heater 32 and measures the amount of heat generated by the heater 32.
The A / D converter 34 A / D converts the output of the temperature sensor 33 and outputs it to the CPU 31.
The shutter opening / closing device 35 chops the emission of infrared rays due to heat generation by opening / closing the shutter under the control of the CPU 31.
The communication I / F 36 inputs and outputs data with the external infrared sensor unit 2.

  In the vehicle temperature measuring apparatus 1 according to the first embodiment, as shown in FIG. 1, the infrared sensor unit 2 is provided at a position where the head of the passenger of the instrument panel is measured from the lower front, and the standard heating element unit 3. Is provided on the lower surface of the roof. The visible light sensor 23 is provided at a position where the external light on the upper part of the instrument panel can be easily captured.

Next, the operation will be described.
[Temperature measurement processing]
FIG. 3 is a flowchart showing a flow of temperature measurement / calibration processing executed by the vehicle temperature measurement apparatus according to the first embodiment. Each step will be described below.

  Step S1 shows that it is an idle state before a process.

  In step S2, the atmospheric temperature in the passenger compartment is detected from the detection result of the temperature sensor 33 before the heater 32 generates heat, and the heat generation temperature in the heater 32, that is, the standard heating element unit 3, is set according to the atmospheric temperature.

  In step S3, the heater 32 of the standard heating element unit 3 is turned on.

  In step S4, the heat generation temperature of the standard heat generating unit 3 that has generated heat is measured.

  In step S5, it is determined whether the heat generation temperature is within the target temperature range. If it is within the range, the process proceeds to step S6, and if not within the range, the process proceeds to step S4.

  In step S6, the shutter device 35 of the standard heating element unit 3 is operated to start opening / closing the shutter.

  In step S <b> 7, the temperature distribution in the passenger compartment is measured by the thermopile module 21.

  In step S8, it is determined whether there is a disturbance due to visible light. If there is a disturbance, the process proceeds to step S7, and if there is no disturbance (very small), the process proceeds to step S9.

  In step S9, it is determined whether or not all the elements of the thermopile module 21 have changed uniformly. If there is a uniform change, the process proceeds to step S10. If not, the process proceeds to step S7. Transition.

  In step S10, calculation of data for correcting a uniform change to all elements is performed.

  In step S <b> 11, the measured vehicle interior temperature distribution data is output to the air conditioning control unit 4.

  In step S12, it is determined whether or not to continue the measurement by communication with the air conditioning control unit 4. If the measurement is continued, the process proceeds to step S7, and if not, the process proceeds to step S13.

  In step S13, the heater 32 of the standard heating element unit 3 is turned off.

[Improved accuracy of temperature distribution measurement in passenger compartment]
In the first embodiment, 16 elements are detected by the thermopile module 21 in which the elements are arranged in one row in the horizontal direction. The CPU 24 scans the 16-element thermopile, samples data, and measures the temperature distribution in the horizontal direction in the passenger compartment by calculation.
If a moving mechanism for scanning the thermopile module 21 in the vertical direction is provided, two-dimensional temperature distribution measurement is also possible.

In this measurement, any of the 16 elements of the thermopile module 21 detects the standard heating element unit 3. Since the standard heating element unit 3 generates heat in accordance with the atmospheric temperature in the passenger compartment, it generates heat at a temperature close to the detected passenger compartment temperature. The heat generation temperature is detected by the CPU 31 by the temperature sensor 33 and is accurately maintained at a predetermined temperature by controlling the heater 32.
Therefore, if the temperature of the standard heating element unit 3 detected by the thermopile module 21 is calibrated as the heater 32 set temperature, a highly accurate measurement is performed.
Furthermore, in Example 1, the infrared radiation of the standard heating element unit 3 by the shutter opening / closing device 35 is made intermittent by chopping, that is, a specific frequency. Therefore, if the temperature distribution of the thermopile module 21 to be detected and processed by the CPU 24 is the position of the standard heating element unit 3 and is a signal synchronized with the intermittent chopping frequency, the calibration is performed. Calibration will be performed with infrared light generated by the heat generated by the standard heating element unit 3 which is not affected by disturbance, and the accuracy is further improved.

  Further, when performing this calibration and measurement, the state of disturbance is measured by the visible light sensor 23. Therefore, when it is determined that the state of disturbance is not suitable for measurement, the thermopile module 21 Since the re-measurement is performed (step S8), the accuracy is further improved.

Furthermore, when it is determined from the detection result of the visible light sensor 23 that the state of disturbance is suitable for measurement, when the thermopile module 21 changes uniformly as indicated by reference numeral 53 in FIG. The measurement is performed with the accuracy improved by correcting the amount of change and removing the influence of disturbances that are not enough to stop the measurement. In other words, it corrects the disturbance that is incident from outside the field of view of the thermopile module 21 such as the side wall of the mounting portion of the infrared sensor unit 2 and is averagely applied to all elements, and improves the measurement accuracy by removing the influence. It is.
It should be noted that no correction is performed when only specific elements have changed as indicated by reference numerals 51 and 52 in FIG.

  Thus, if the temperature distribution image including the head of the occupant h and the standard heating element unit 3 is obtained with high accuracy, the air conditioning control unit 4 can more accurately obtain the head position and temperature of the occupant. By performing the control according to it, it becomes a more comfortable interior space.

  Next, the effect will be described.

  In the vehicle temperature measurement device according to the first embodiment, the effects listed below can be obtained.

  (1) Detection of the thermopile module 21 in the vehicle temperature measuring apparatus 1 including the infrared sensor unit 2 that detects infrared light emitted from the vehicle interior by the 16-element thermopile module 21 and measures the temperature in a distribution. Because the CPU 24 of the infrared sensor unit 2 performs calibration of the thermopile module 21 based on the detection result of the standard heating element unit 3 that generates heat at a predetermined temperature within the target range and the thermopile module 21, the influence of ambient light Even when there is, it is possible to accurately measure the temperature distribution in the passenger compartment. Thereby, while measuring the surface temperature of a passenger | crew correctly, the distance from the blower outlet of an air conditioning to a passenger | crew can be estimated more correctly, and more comfortable air-conditioning control can be performed.

  (2) The standard heating element unit 3 detects the temperature in the vehicle interior and detects the temperature of the heater 32, and changes the heat generation temperature of the heater 32 according to the control of the CPU 31 according to the temperature in the vehicle interior. The calibration can be performed according to the temperature to be measured, and the temperature can be measured with higher accuracy.

  (3) The standard heating element unit 3 is provided with a shutter opening / closing device 35 for intermittently emitting infrared radiation due to heat generation. The CPU 24 of the infrared sensor unit 2 uses a signal synchronized with the chopping frequency of the standard heating element unit 3 as a standard. Since the temperature detection signal of the heating element unit 3 is used, the temperature measurement can be performed more accurately without being affected by disturbance.

  (4) The infrared sensor unit 2 includes a thermopile module 21 in which a plurality of elements are arranged in the lateral direction, a visible light sensor 23 for measuring the state of disturbance light, and a CPU 24 serving as the calibration means for processing detection data. The chopping means of the standard heating element unit 3 is a shutter opening / closing device 35 that opens and closes a shutter provided in the direction of heat radiation to the infrared sensor and performs intermittent heat radiation. The head and the standard heating element unit 3 can be captured and infrared light can be chopped by opening and closing the shutter to accurately measure the temperature in the passenger compartment including the passenger's head.

  As mentioned above, although the temperature measuring apparatus for vehicles of this invention has been demonstrated based on Example 1, it is not restricted to these Examples about a concrete structure, Invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

For example, in the first embodiment, a disturbance state is detected by a visible light sensor and calibration / measurement is performed in a state where there is little disturbance. However, calibration may be performed at night when there is little disturbance.
In the first embodiment, for the sake of explanation, calibration and measurement are performed for one measurement. However, calibration may be performed for each of a plurality of measurements, time, and use. It is desirable to store the data until calibration is completed.

1 is a schematic view of a vehicle temperature measuring device according to Embodiment 1. FIG. 1 is a block diagram of a vehicle temperature measurement device according to Embodiment 1. FIG. It is a flowchart figure which shows the flow of the process of the temperature measurement and calibration performed with the temperature measuring apparatus for vehicles of Example 1. FIG. It is explanatory drawing which shows the relationship of each element of the thermopile module of the temperature measuring apparatus for vehicles of Example 1, time, and temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Temperature measuring device for vehicles 2 Infrared sensor unit 21 Thermopile module 22 Analog filter 23 Visible light sensor 24 CPU
25 A / D converter 26 Communication I / F
3 Standard heating element unit 31 CPU
32 Heater 33 Temperature sensor 34 A / D converter 35 Shutter opening / closing device 36 Communication I / F
4 Air conditioning control unit 5 Seat 6 Car body h Crew

Claims (4)

Infrared sensor that detects infrared light radiated in the passenger compartment by multiple elements and measures temperature in distribution,
In a vehicle temperature measuring device,
A standard heating element that generates heat at a predetermined temperature within a detection target range of the infrared sensor; and
Means for calibrating the infrared sensor from the detection result of the standard heating element by the infrared sensor;
A vehicle temperature measuring device comprising: The vehicle temperature measuring device according to claim 1,
The standard heating element is
Means for detecting the temperature in the passenger compartment;
Means for changing the heat generation temperature according to the vehicle interior temperature;
A vehicle temperature measurement device comprising: In the vehicle temperature measuring device according to claim 1 or 2,
The standard heating element is
Equipped with chopping means to make the infrared radiation due to heat generation intermittent radiation,
The infrared sensor calibration means comprises:
A signal synchronized with the chopping frequency of the standard heating element is a temperature detection signal of the standard heating element.
A vehicle temperature measuring device. In the vehicle temperature measuring device according to claim 3,
The infrared sensor is
A thermopile array in which a plurality of elements are arranged in the horizontal direction;
A visible light sensor for measuring the state of disturbance light,
It consists of a CPU that is the calibration means for processing detection data,
The standard heating element chopping means is:
A shutter opening and closing device that performs intermittent heat dissipation by opening and closing a shutter provided in the heat dissipation direction to the infrared sensor,
A vehicle temperature measuring device.