JP2008117224A - On-vehicle information device, and temperature control method for on-vehicle information device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly control a temperature inside an on-vehicle information device such as a navigation device. <P>SOLUTION: In this on-vehicle information device, after executing processing A-E, addition values Ia-Ie according to processing loads of the processing A-E are added to an execution instruction counter value. When operating in a sleep mode, a subtraction value Ds according to a sleep time thereof is subtracted from the execution instruction counter value. Based on the thus increased and reduced execution instruction counter value, the temperature inside the device is estimated, and the temperature control inside the device is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a temperature control method in an in-vehicle information device such as a navigation device.

  2. Description of the Related Art Conventionally, a navigation device that detects a heat generation temperature of a switching power supply device mounted in a navigation device and controls the heat generation temperature within a predetermined range by changing a switching frequency according to the detection result is known. (See Patent Document 1).

JP 2003-88109 A

  In recent years, in order to realize higher performance and higher functionality of navigation devices, the speed of microprocessors mounted on navigation devices has been increased. Along with this, the amount of heat generated from the microprocessor is increasing. However, in the navigation device disclosed in Patent Document 1, the heat generation temperature of the switching power supply device can be controlled, but the heat generation temperature of the microprocessor cannot be controlled. Therefore, the temperature in the apparatus cannot be properly controlled.

The in-vehicle information device according to the first aspect of the present invention is based on processing means for executing various signal processing executed in the control unit of the in-vehicle information device and the temperature in the device based on the history of signal processing executed by the processing means. Temperature estimation means for estimation and temperature control means for controlling the temperature in the apparatus based on the temperature estimation result by the temperature estimation means are provided.
According to a second aspect of the present invention, in the in-vehicle information device according to the first aspect, the vehicle information processing apparatus further includes a counter increasing / decreasing unit that increases or decreases an execution instruction counter value according to a history of signal processing executed by the processing unit. The temperature in the apparatus is estimated based on the execution instruction counter value.
According to a third aspect of the present invention, in the in-vehicle information device according to the second aspect, when the processing means executes predetermined signal processing, the counter increasing / decreasing means increases the execution instruction counter value according to the processing load. .
According to a fourth aspect of the present invention, in the in-vehicle information device according to the second or third aspect, when the processing unit operates in the sleep mode, the counter increasing / decreasing unit decreases the execution instruction counter value according to the operation time.
According to a fifth aspect of the present invention, in the in-vehicle information device according to any one of the second to fourth aspects, an initial counter value calculating means for calculating an initial value of an execution instruction counter value when the power of the in-vehicle information device is turned on. Is further provided.
The invention of claim 6 further comprises recording means for recording an execution instruction counter value and time when the power of the in-vehicle information apparatus is turned off in the in-vehicle information apparatus of claim 5, wherein the initial counter value calculation means comprises: The initial value of the execution instruction counter value is calculated based on the execution instruction counter value and time recorded by the recording means at the previous power-off.
According to a seventh aspect of the present invention, in the in-vehicle information device according to the sixth aspect, the initial counter value calculating means calculates the power-off time based on the time recorded by the recording means at the previous power-off, and the power-off time The initial value of the execution instruction counter value is calculated by subtracting the corresponding subtraction value from the execution instruction counter value recorded by the recording means at the previous power-off.
The invention of claim 8 is the in-vehicle information device according to any one of claims 1 to 7, wherein the temperature control means is configured such that when the temperature in the apparatus estimated by the temperature estimation means exceeds a predetermined threshold value, The temperature in the apparatus is controlled by executing a predetermined processing load reduction measure for reducing the processing load of the processing means.
The temperature control method for the in-vehicle information device according to the invention of claim 9 is a method for controlling the temperature in the device of the in-vehicle information device provided with processing means for executing various signal processing, and executed by the processing means. The temperature in the apparatus is estimated based on the history of signal processing, and the temperature in the apparatus is controlled based on the estimation result.
According to a tenth aspect of the present invention, in the temperature control method for an in-vehicle information device according to the ninth aspect, the execution instruction counter value is increased or decreased according to the history of the signal processing executed by the processing means, and the execution instruction counter value is set. Based on this, the temperature inside the apparatus is estimated.

  ADVANTAGE OF THE INVENTION According to this invention, in vehicle information devices, such as a navigation apparatus, the temperature in the apparatus can be controlled appropriately.

  FIG. 1 shows a configuration of a navigation device 1 according to an embodiment of the present invention. The navigation device 1 is mounted on a vehicle, and the control unit 10 executes various signal processes for guiding the vehicle to a destination. Furthermore, the temperature in the apparatus is estimated based on the history of signal processing executed in the control unit 10, and the temperature in the apparatus is appropriately controlled based on the estimation result. The navigation device 1 includes a controller 10, a vibration gyro 11, a vehicle speed sensor 12, a hard disk (HDD) 13, a GPS receiver 14, a display monitor 15, and an input device 16.

  The control unit 10 includes a microprocessor, various peripheral circuits, a RAM, a ROM, and the like, and executes various signal processes based on a control program and map data recorded in the HDD 13. Various processes for guiding the vehicle to the destination are executed in the navigation device 1 by the signal processing performed by the control unit 10. For example, destination search processing when setting a destination, search processing for a recommended route to the set destination, vehicle current position detection processing, various image display processing, voice output processing during route guidance, etc. Is executed. In addition, in order to control the temperature in the apparatus, processing as described later is also executed in the control unit 10.

  The vibration gyro 11 is a sensor for detecting the angular velocity of the host vehicle. The vehicle speed sensor 12 is a sensor for detecting the vehicle speed. By detecting the motion state of the vehicle at predetermined time intervals using these sensors, the amount of movement of the vehicle position is obtained, and thereby the current vehicle position is detected.

  The HDD 13 is a non-volatile recording medium in which various data including map data are recorded. Map data recorded in the HDD 13 is read out under the control of the control unit 10 as necessary, and is used for various processes and controls executed by the control unit 10. This map data includes route calculation data, route guidance data, road data, and background data. The route calculation data is used for route search to the destination. The route guidance data is used to guide the host vehicle to a destination according to a set route, and represents an intersection name, a road name, and the like. The road data represents the shape of the road. The background data represents map shapes other than roads such as rivers, railways, various facilities on the map (landmarks), and the like.

  In the road data recorded on the HDD 13, the minimum unit representing a road section is called a link, and each road is composed of a plurality of links. A point connecting the links is called a node, and each node has position information (coordinate information). The link shape, that is, the shape of the road is determined based on the position information of the node.

  In the above example, the map data recorded on the HDD 13 is used in the navigation device 1, but the map data may be recorded on a recording medium other than the HDD. For example, map data can be recorded on a CD-ROM, DVD-ROM, memory card, or the like. Or it is good also as receiving the map data transmitted via a mobile telephone line etc. from the outside, and using the map data. That is, any method may be used for acquiring map data.

  The GPS receiver 14 receives a GPS signal transmitted from a GPS satellite and outputs it to the controller 10. The GPS signal includes the position and transmission time of the GPS satellite that transmitted the GPS signal as information for obtaining the position of the vehicle and the current time. Therefore, by receiving GPS signals from a predetermined number or more of GPS satellites, the current position and current time of the vehicle can be calculated based on these pieces of information.

  The display monitor 15 is a device for performing various screen displays in the navigation device 1 and is configured using a liquid crystal display or the like. For example, a map screen is displayed on the display monitor 15. The contents of the screen displayed on the display monitor 15 are determined by screen display control performed by the control unit 10. The display monitor 15 is installed at a position that is easy for the driver to see, such as on the dashboard or in the instrument panel.

  The input device 16 is a device for a driver to perform various input operations for operating the navigation device 1 and includes various input switches. The driver operates the input device 16 to input, for example, the name of a facility or point desired to be set as a destination, select a destination from registered locations registered in advance, or select a map Or scroll in the direction. The input device 16 can be realized by an operation panel, a remote controller, or the like. Alternatively, the input device 16 may be realized by a touch panel integrated with the display monitor 15.

  When the user operates the input device 16 to set a destination, the navigation device 1 searches for a recommended route to the destination by performing a predetermined algorithm operation based on the above-described route calculation data. Then, the current position of the vehicle is detected and the vehicle is guided to the destination according to the searched recommended route while displaying the surrounding road map.

  Next, a temperature control method in the navigation device 1 will be described. As described above, the navigation device 1 estimates the temperature in the device based on the history of signal processing executed in the control unit 10, and appropriately controls the temperature in the device based on the estimation result. At this time, the control unit 10 estimates the temperature in the apparatus by increasing or decreasing a preset counter value according to the history of processing executed. This counter value is called an execution instruction counter value.

  When the control unit 10 executes some signal processing, the execution instruction counter value is increased by an amount corresponding to the processing content. The amount of increase at this time is determined according to the processing load executed by the control unit 10. That is, when a process with a high load (a large amount of calculation) is executed, the increase amount of the execution instruction counter value is set to be large accordingly. On the contrary, when a process with a low load (a small amount of calculation) is executed, the increase amount of the execution instruction counter value is set to be small accordingly. When the control unit 10 operates in the sleep mode or when the navigation device 1 is powered off and the control unit 10 is not operating, the execution instruction counter value is decreased according to the length of time. . In this way, the execution instruction counter value is increased or decreased according to the history of signal processing executed in the control unit 10.

  FIG. 2 is a diagram showing a specific example of how the execution instruction counter value is increased or decreased. This specific example will be described below with the passage of time. First, when the navigation device 1 is turned on and the control circuit 10 starts operating, the control circuit 10 calculates the first execution instruction counter value at the start of the operation. This execution instruction counter value is called an initial counter value.

  The control circuit 10 calculates the initial counter value as follows. As will be described later, when the power of the navigation device 1 is turned off, the control unit 10 records the execution instruction counter value and time at that time in the HDD 13. In this way, the power-off time of the navigation device 1 is calculated by obtaining the difference between the time recorded at the previous power-off time and the current power-on time. By multiplying this power-off time by a predetermined decrease rate Ko, a subtraction value Do from the execution instruction counter value recorded at the previous power-off is obtained. The reduction rate Ko is determined based on the heat radiation efficiency of the control unit 10, the ambient temperature environment estimated from the season and time, the measurement result of the thermometer installed in the vehicle, and the like. The initial counter value is obtained by subtracting the subtraction value Do thus obtained from the execution instruction counter value at the previous power-off. When the subtraction value Do exceeds the execution instruction counter value at the previous power-off, the initial counter value is set to zero.

  After the initial counter value is determined as described above, when the control unit 10 executes the process A, the addition value Ia is added to the initial counter value that is the execution instruction counter value at that time. This added value Ia is determined according to the load of the process A. For example, an addition value Ia corresponding to the process A can be determined by previously creating a table of addition values for each process executed in the control unit 10 and referring to the table. Alternatively, the addition value Ia may be determined based on the calculation amount or the number of steps when the process A is executed.

  After that, when the control unit 10 executes the process B and the process C, the addition value Ib and the addition value Ic corresponding to each process are added to the execution instruction counter value as in the case where the process A is executed. The addition value Ib and the addition value Ic at this time are also determined in the same manner as the addition value Ia. In the example of FIG. 2, the added value Ic is shown larger than the added value Ia, and the added value Ib is shown larger than the added value Ic. Therefore, it can be seen that the load is higher in the order of process B, process C, and process A.

  After execution of process C, when there is no process to be executed in the control unit 10 (idle state), the control unit 10 starts an operation in the sleep mode. At this time, the sleep start time is recorded in the HDD 13 and then the mode shifts to the sleep mode. When the control unit 10 operates in the sleep mode in this way and a process to be executed in the control unit 10 occurs, the control unit 10 ends the sleep mode and enters a wake-up state. At this time, the sleep mode subtraction value Ds is subtracted from the execution instruction counter value.

  The control circuit 10 calculates the subtraction value Ds for the sleep mode as follows. First, the operation time (sleep time) of the sleep mode is calculated by obtaining the difference between the sleep start time recorded at the time of transition to the sleep mode and the sleep end time. The sleep mode subtraction value Ds is obtained by multiplying the sleep time by a predetermined decrease rate Ks. The reduction rate Ks at this time is also determined based on the heat dissipation efficiency of the control unit 10 and the like, similar to the reduction rate Ko when the power is turned off. The subtraction value Ds thus obtained is subtracted from the execution instruction counter value. When the subtraction value Ds exceeds the current execution instruction counter value, the execution instruction counter value after subtraction is set to zero.

  After that, when the control unit 10 executes the process D and the process E, the addition value Id and the addition value Ie corresponding to the respective processes are obtained with respect to the execution instruction counter value in the same manner as when the processes A, B, and C are executed. And add. The addition value Id and the addition value Ie at this time are also determined in the same manner as the addition values Ia, Ib, and Ic described above.

  After the process E is executed, when the power of the navigation device 1 is turned off in accordance with the operation of the power switch or the engine stop of the vehicle, the control unit 10 records the execution instruction counter value and the time at that time in the HDD 13. To stop its operation. The execution instruction counter value and time at the time of power-off recorded in this way are used to calculate the next initial counter value as described above. As described above, the execution instruction counter value is increased or decreased according to the history of signal processing executed in the control unit 10.

  The execution command counter value is stored in the RAM in the control unit 10 when the navigation device 1 is operating, and is read out from the RAM every predetermined time and used for temperature estimation in the navigation device 1. It is done. That is, the control unit 10 calculates a temperature rise estimated value of the control unit 10 by multiplying the read execution instruction counter value by a predetermined conversion rate. By adding this estimated temperature rise value to the ambient temperature, the estimated temperature value in the navigation device 1 is obtained.

  When the estimated temperature value thus obtained exceeds a predetermined threshold value, the control unit 10 executes a processing load reduction measure for reducing its own processing load. For example, the drawing update interval when updating the display content of the map screen is made longer than in the normal state. Thereby, the temperature in the apparatus is appropriately controlled while the navigation apparatus 1 is operated. When the processing load reduction measure is being executed, the execution instruction counter value is decreased accordingly.

  3 and 4 show flowcharts of processing executed by the control unit 10 when the temperature control of the navigation device 1 is performed as described above. The flowchart of FIG. 3 is a flowchart of the execution instruction counter process executed when the execution instruction counter value is calculated. The flowchart of FIG. 4 monitors the temperature in the apparatus based on the execution instruction counter value calculated by the execution instruction counter process of FIG. 3, and the temperature monitoring process executed when performing temperature control according to the monitoring result. It is a flowchart. Hereinafter, description will be given first with reference to the flowchart of FIG.

  In step S <b> 10, the execution instruction counter value and time recorded at the previous power-off are read from the HDD 13. The execution instruction counter value and the time read here are those recorded at the time of the previous power-off in step S180 described later. In the next step S20, the power-off time from the previous power-off to the current power-on is calculated from the difference between the time read in step S10 and the current time.

  In step S30, an initial counter value is calculated. Here, as described above, the subtraction value Do is obtained by multiplying the power-off time calculated in step S20 by a predetermined decrease rate Ko, and the subtraction value Do is read in step S10 and executed at the previous power-off time. An initial counter value is calculated by subtracting from the instruction counter value.

  In step S40, it is determined whether the control unit 10 has executed some signal processing. When any signal processing is executed, the process proceeds to step S50. In step S50, the addition value corresponding to the load of the signal processing executed in step S40 is determined as described above. In the next step S60, the addition value determined in step S50 is added to the execution instruction counter value. Thereby, the execution instruction counter value is increased according to the load of the executed process. If step S60 is performed, it will progress to step S70. On the other hand, when it determines with the control part 10 not performing any signal processing in step S40, it progresses to step S70, without performing step S50 and S60.

  In step S70, it is determined whether to start the sleep mode. If there is no process to be executed in the control unit 10, it is determined that the sleep mode is started, and the process proceeds to the next step S80. On the other hand, when the sleep mode is not started, the process proceeds to step S140 without executing the processes of steps S80 to S130 described below.

  In step S80, the current time at that time is recorded in the HDD 13 as the sleep start time. Thereafter, the control unit 10 shifts to the sleep mode. In the next step S90, it is determined whether or not the sleep mode has been canceled. When the process which should be performed in the control part 10 generate | occur | produces, it determines with the sleep mode having been cancelled | released and progresses to step S100. At this time, the control unit 10 ends the sleep mode and enters a wake-up state.

  In step S100, the sleep start time recorded in step S80 is read from the HDD 13. In the next step S110, the sleep time is calculated from the difference between the sleep start time read in step S100 and the current time. In the next step S120, a subtraction value is calculated based on the sleep time calculated in step S110. Here, as described above, the sleep mode subtraction value Ds is obtained by multiplying the sleep time by a predetermined decrease rate Ks. In step S130, the subtraction value Ds calculated in step S120 is subtracted from the execution instruction counter value. Thus, the execution instruction counter value is decreased according to the sleep time. If step S130 is performed, it will progress to step S140.

  In step S140, the control unit 10 determines whether or not a processing load reduction measure is being executed. As described above, for example, when processing load reduction measures such as making the drawing update interval for updating the display content of the map screen longer than usual are being executed, the process proceeds to step S150. This processing load reduction measure is executed in step S240 of FIG. 4 described later. On the other hand, when such a processing load reduction measure is not being executed, the process proceeds to step S170 without executing the processes of steps S150 and S160 described below.

  In step S150, a subtraction value corresponding to the processing load reduction measure being executed is determined. Here, for example, a subtraction value can be determined using a preset value. In the next step S160, the subtraction value determined in step S150 is subtracted from the execution instruction counter value. As a result, the execution instruction counter value is decreased according to the processing load reduction measure being executed. If step S160 is performed, it will progress to step S170.

  In step S170, it is determined whether or not to turn off the power of the navigation device 1. If an instruction to turn off the power is given by operating the power switch or stopping the engine of the vehicle, the process proceeds to step S180. In step S180, the execution instruction counter value and time at that time are recorded in the HDD 13. If step S180 is performed, the flowchart of FIG. 3 will be complete | finished. Thereafter, the operation of the control unit 10 is stopped and the power of the navigation device 1 is turned off. On the other hand, if it is determined in step S170 that the power is not turned off, the process returns to step S40 and the above-described processing is repeated. In the execution instruction counter process, the process as described above is executed.

  Next, the flowchart of FIG. 4 will be described. In step S210, the current execution instruction counter value is read from the RAM in the control unit 10. The execution instruction counter value read here is obtained by the execution instruction counter process shown in the flowchart of FIG. In the next step S220, an estimated temperature value in the navigation device 1 is calculated based on the execution command counter value read in step S210. Here, as described above, the estimated temperature rise value of the control unit 10 is calculated by multiplying the read execution instruction counter value by a predetermined conversion rate. By adding this estimated temperature rise value to the ambient temperature, the estimated temperature value is calculated.

  In step S230, it is determined whether or not the estimated temperature value calculated in step S220 exceeds a predetermined threshold value. If the threshold is exceeded, the process proceeds to step S240. In step S240, a processing load reduction measure for reducing the processing load of the control unit 10 is executed. Here, as described above, for example, the drawing update interval when updating the display content of the map screen is made longer than usual to reduce the processing load of the control unit 10. If such a processing load reduction measure is executed in step S240, the process returns to step S210 and the above-described processing is repeated. On the other hand, if it is determined in step S230 that the estimated temperature value does not exceed the threshold value, the process returns to step S210 without executing step S240. In the temperature monitoring process, the process described above is executed.

According to the embodiment described above, the following operational effects can be obtained.
(1) The temperature in the apparatus is estimated based on the history of signal processing executed by the control unit 10 (step S220), and the temperature in the apparatus is controlled based on the estimation result. Since it did in this way, in vehicle information devices, such as a navigation device, the temperature in the device can be controlled appropriately.

(2) The execution instruction counter value is increased or decreased according to the history of signal processing executed by the control unit 10 (steps S60, S130, S160). In step S220, the temperature in the apparatus is estimated based on the execution instruction counter value. Since it did in this way, the temperature in an apparatus can be estimated, without using a temperature sensor.

(3) It is determined whether or not the control unit 10 has performed any signal processing (step S40). When it is determined that the signal processing has been performed, an addition value is determined according to the processing content (step S50). The determined addition value is added to the execution instruction counter value (step S60). Thus, when the control unit 10 executes predetermined signal processing, the execution instruction counter value is increased according to the processing load. Since it did in this way, according to the temperature rise in an apparatus by execution of the signal processing in the control part 10, an execution command counter value can be increased appropriately.

(4) It is determined whether or not to start the sleep mode (step S70). When it is determined that the sleep mode is started, the sleep start time is recorded in the HDD 13 (step S80). Thereafter, when the sleep mode is canceled (step S90), the recorded sleep start time is read (step S100), and the sleep time is calculated based on the sleep start time (step S110). A subtraction value is determined based on the sleep time thus calculated (step S120), and the determined subtraction value is subtracted from the execution instruction counter value (step S130). Thus, when the control unit 10 operates in the sleep mode, the execution instruction counter value is decreased according to the operation time. Since it did in this way, according to the temperature fall in an apparatus by the sleep mode operation | movement of the control part 10, an execution command counter value can be decreased appropriately.

(5) Since the initial value of the execution instruction counter value is calculated when the apparatus is turned on (step S30), the execution instruction counter value is suitable for estimating the temperature in the apparatus. Can do.

(6) The execution instruction counter value and time when the apparatus is powered off are recorded in the HDD 13 (step S180). When the apparatus is turned on, the execution instruction counter value and time recorded at the time of the previous power-off are read from the HDD 13 (step S10). Then, based on the read time at the previous power-off time, the power-off time is calculated (step S20), and the subtraction value corresponding to the power-off time is executed at the time of the previous power-off time read out. By subtracting from the instruction counter value, an initial value of the execution instruction counter value is calculated (step S30). As a result, the initial value of the execution instruction counter value is calculated based on the execution instruction counter value and the time recorded at the previous power-off. Since this is done, the initial value of the execution instruction counter value can be accurately calculated by reflecting the previous result.

(7) It is determined whether or not the temperature in the apparatus estimated in step S220 exceeds a predetermined threshold value (step S230). When the temperature exceeds the threshold value, the processing load on the control unit 10 is reduced. A processing load reduction measure is executed (step S240). Thereby, the temperature in the apparatus was controlled. Since it did in this way, the temperature in the apparatus can be controlled appropriately with the apparatus operated.

  Although the application example of the navigation device has been described in the above embodiment, the present invention can be applied to various in-vehicle information devices including a control circuit that executes various signal processes in addition to the navigation device. For example, a vehicle travel control device that performs vehicle travel control when traveling on a curve based on the vehicle position detected by the navigation device, or in-vehicle information that provides various image information and audio information to a vehicle occupant The present invention can also be applied to terminals and the like.

  The embodiments and modifications described above are merely examples, and the present invention is not limited to these contents as long as the features of the invention are not impaired.

  In the above embodiment, the recording means is realized by the HDD 13 and other means described in the claims are realized by processing performed by the control unit 10. However, these are merely examples, and when interpreting the invention, there is no limitation or restriction on the correspondence between the items described in the above embodiments and the items described in the claims.

It is a block diagram of the navigation apparatus by one Embodiment of this invention. It is the figure which showed the specific example of a mode that an execution command counter value was increased / decreased. It is a flowchart of the execution instruction counter process performed at the time of calculation of an execution instruction counter value. It is a flowchart of the temperature monitoring process performed when monitoring the temperature in an apparatus based on the execution command counter value and performing temperature control according to the monitoring result.

Explanation of symbols

1: Navigation device 10: Control unit 11: Vibration gyro 12: Vehicle speed sensor 13: HDD 14: GPS receiving unit 15: Display monitor 16: Input device

Claims (10)

Processing means for executing various signal processing executed in the control unit of the in-vehicle information device;
Temperature estimating means for estimating the temperature in the apparatus based on the history of signal processing executed by the processing means;
An in-vehicle information device comprising: temperature control means for controlling the temperature in the apparatus based on a temperature estimation result by the temperature estimation means. The in-vehicle information device according to claim 1,
Counter increasing / decreasing means for increasing or decreasing the execution instruction counter value according to the history of signal processing executed by the processing means,
The in-vehicle information device characterized in that the temperature estimation means estimates the temperature in the device based on the execution command counter value. The in-vehicle information device according to claim 2,
The counter increasing / decreasing means, when the processing means executes predetermined signal processing, increases the execution instruction counter value according to the processing load. The in-vehicle information device according to claim 2 or 3,
The counter increasing / decreasing unit decreases the execution instruction counter value according to an operation time when the processing unit operates in a sleep mode. The in-vehicle information device according to any one of claims 2 to 4,
An in-vehicle information device further comprising initial counter value calculating means for calculating an initial value of the execution instruction counter value when the in-vehicle information device is powered on. The in-vehicle information device according to claim 5,
It further comprises recording means for recording the execution command counter value and time when the power of the in-vehicle information device is turned off,
The in-vehicle information device characterized in that the initial counter value calculation means calculates an initial value of the execution instruction counter value based on the execution instruction counter value and time recorded by the recording means when the power was last turned off. The in-vehicle information device according to claim 6,
The initial counter value calculating means calculates a power-off time based on the time recorded by the recording means at the previous power-off, and a subtraction value corresponding to the power-off time is calculated by the recording means at the previous power-off. An in-vehicle information device characterized in that an initial value of the execution instruction counter value is calculated by subtracting from the recorded execution instruction counter value. In the in-vehicle information device according to any one of claims 1 to 7,
The temperature control means executes a predetermined processing load reduction measure for reducing the processing load of the processing means when the temperature in the apparatus estimated by the temperature estimation means exceeds a predetermined threshold value. An on-vehicle information terminal characterized by controlling the temperature in the apparatus. A method of controlling the temperature in the in-vehicle information device having processing means for executing various signal processing,
Estimating the temperature in the apparatus based on the history of signal processing performed by the processing means,
A temperature control method for an in-vehicle information device, wherein the temperature in the device is controlled based on the estimation result. The temperature control method for an in-vehicle information device according to claim 9,
Increase or decrease the execution instruction counter value according to the history of signal processing executed by the processing means,
A temperature control method for an in-vehicle information device, wherein the temperature in the device is estimated based on the execution command counter value.

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