JP2012245936A - Occupant detection device, and occupant detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an occupant detection device and an occupant detection method capable of suitably switching between the permission and prohibition of the operation of a safety device without providing a dedicated sensor.SOLUTION: This occupant detection device for detecting the presence or absence of an occupant on a vehicle having a seat with a heater heated by electric power includes a current difference detection part 12 for detecting the difference between the current values flowing to the heater at predetermined two different times, a determination part 13 for determining whether the difference detected by the current difference detection part comes within a predetermined determination range or not, and a signal output part 15 for outputting a predetermined signal when the determination part determines that the difference comes within the determination range.

Description

  The present invention relates to an occupant detection device and an occupant detection method for performing switching control for enabling and disabling a safety device.

  2. Description of the Related Art Conventionally, there is an occupant detection device that detects the presence or absence of an occupant in a seat when operating a safety device provided in a seat other than the driver's seat (for example, see Patent Document 1). In such an occupant detection device, only when it is detected that there is an occupant, control is performed such that a safety device such as a warning for wearing an airbag and a seat belt can be activated.

  Patent Document 1 discloses an occupant detection device that determines whether an occupant is seated on a seat based on a load detected by a load sensor installed between the seat and a floor.

  Thereby, the operation | movement of an unnecessary airbag can be reduced, the repair cost which restores the operated airbag can be reduced, and the warning operation | movement which wears an unnecessary seatbelt can be eliminated.

Japanese Patent No. 4521886

  However, when a dedicated sensor for occupant detection is provided as in the occupant detection device disclosed in Patent Document 1, there is a problem that the number of in-vehicle electrical components increases and the component cost increases.

  The present invention has been made in view of such circumstances, and provides an occupant detection device and an occupant detection method for suitably switching between enabling and disabling of a safety device without providing a dedicated sensor. For the purpose.

  An occupant detection device according to a first aspect of the present invention is an occupant detection device that detects the presence or absence of an occupant in a vehicle including a seat provided with a heater that generates heat by electric power, and a current value that is supplied to the heater at two different predetermined times. A current difference detection unit that detects a difference between the current difference detection unit, a determination unit that determines whether or not the difference detected by the current difference detection unit is included in a predetermined determination range, and if the difference is included in the determination range, And a signal output unit that outputs a predetermined signal when the determination unit determines.

  In this occupant detection device, the current difference detection unit detects a difference between current values supplied to heaters that generate heat due to electric power at two different predetermined time points. The determination unit determines whether the detected difference is included in a predetermined determination range. A predetermined signal is output when the difference is included in the determination range.

  An occupant detection device according to a second aspect of the present invention includes a storage unit that stores information related to the determination range.

  In this occupant detection device, the storage unit stores information on the determination range.

  An occupant detection device according to a third aspect of the present invention includes a temperature detector that detects a temperature in a vehicle interior, and the storage unit stores information related to the determination range corresponding to each of a plurality of temperatures in the vehicle interior, The determination unit is configured to acquire information related to a determination range corresponding to the temperature in the passenger compartment detected by the temperature detector from the storage unit.

  In this occupant detection device, the temperature detector detects the temperature in the passenger compartment. A memory | storage part memorize | stores the information which concerns on the determination range corresponding to each of several temperature in a vehicle interior. A determination part acquires the information which concerns on the determination range corresponding to the temperature in the vehicle interior which the temperature detector detected from the memory | storage part.

  An occupant detection device according to a fourth aspect of the present invention includes a voltage detection unit that detects a voltage applied to the heater, and the storage unit stores information on the determination range corresponding to each of a plurality of voltages, and the determination The unit is configured to acquire information related to a determination range corresponding to the voltage detected by the voltage detection unit from the storage unit.

  In this occupant detection device, the voltage detection unit detects the voltage applied to the heater. The storage unit stores information related to determination ranges corresponding to a plurality of voltages, respectively. The determination unit acquires information related to a determination range corresponding to the voltage detected by the voltage detection unit from the storage unit.

  The occupant detection device according to a fifth aspect of the present invention is characterized in that one of the two predetermined time points is when the energization of the heater is started, and the other time point is after the start of energization.

  In this occupant detection device, the current difference detection means detects a difference between a current value that is energized to the heater at the start of energization and a current value that is energized to the heater after a predetermined time has elapsed since the start of energization.

  An occupant detection device according to a sixth aspect of the present invention is the occupant detection device that detects the presence or absence of an occupant in a vehicle that includes a heater that generates heat by electric power in each of a plurality of seats including a driver's seat. A current difference detecting unit for detecting a difference in current value supplied to the heater, and a difference detected by the current difference detecting unit of the heater provided in a seat different from the driver seat, and the driver seat. A determination unit that determines whether a difference from the difference detected by the current difference detection unit of the heater is included in a predetermined determination range; and the determination unit determines that the difference is included in the determination range And a signal output unit for outputting a predetermined signal.

  In this occupant detection device, the current difference detection unit calculates a difference between current values supplied to the heaters at two predetermined time points that differ for each heater that generates heat due to electric power provided in each of a plurality of seats including the driver's seat. Detect each one. The difference between the difference detected by the current difference detection unit of the heater provided in the seat different from the driver seat and the difference detected by the current difference detection unit of the heater provided in the driver seat is a predetermined value. It is determined whether or not it is included in the determination range. When it is determined that the difference is included in the determination range, the signal output unit outputs a predetermined signal.

  An occupant detection device according to a seventh aspect of the present invention is the occupant detection device that detects the presence or absence of an occupant in a vehicle provided with a heater that is heated by electric power in each of a plurality of seats including the driver's seat. The difference between the current value energized to the heater of the driver seat at a predetermined time and the current value energized to the heater of the seat at a predetermined time after the start of energization of the heater of the seat different from the driver seat A current difference detection unit to detect; a determination unit that determines whether or not a difference detected by the current difference detection unit is included in a predetermined determination range; and the determination unit includes the difference in the determination range A signal output unit that outputs a predetermined signal when it is determined.

  In this occupant detection device, the current difference detector is a driver's seat at a predetermined time after the start of energization of the heater in the driver's seat among the heaters heated by the electric power provided in each of the plurality of seats including the driver's seat A difference between a current value to be supplied to the heater of the seat and a current value to be supplied to the heater of the seat at a predetermined time after the start of energization of the heater of the seat different from the driver's seat is detected. The determination unit determines whether the detected difference is included in a predetermined determination range. When it is determined that the difference is included in the determination range, the signal output unit outputs a predetermined signal.

  An occupant detection method according to an eighth aspect of the invention is a method for detecting the presence or absence of an occupant of a vehicle having a seat provided with a heater that generates heat by electric power, and a difference between current values supplied to the heater at two different predetermined times. A step of determining whether the difference detected in the step is included in a predetermined determination range, and the determination unit determines that the difference is included in the determination range. And a step of outputting the following signal.

  In this occupant detection method, a difference in current value applied to a heater that generates heat by electric power provided in a seat at two different predetermined times is detected. It is determined whether or not the detected difference is included in a predetermined determination range. When it is determined that the difference is included in the determination range, a predetermined signal is output.

  According to the occupant detection device and the occupant detection method according to the present invention, there is provided an occupant detection device and an occupant detection method for suitably switching between enabling and disabling of the safety device without providing a dedicated sensor. Can be provided.

It is a block diagram which shows the principal part structure of embodiment of the passenger | crew detection apparatus which concerns on this invention. It is a graph which shows the example of the change of the electric current value with which electricity is supplied to a seat heater. It is a flowchart which shows the outline of the procedure of embodiment (the 1) of the passenger | crew detection method which concerns on this invention. It is a flowchart which shows the example of the procedure of the process which detects the difference of an electric current value. It is a flowchart which shows the process which controls a safety device. It is a flowchart which shows the procedure of the passenger | crew detection method (the 2) based on this invention. It is a block diagram which shows the principal part structure of embodiment of the passenger | crew detection apparatus which concerns on this invention. It is a sequence diagram which shows the procedure of embodiment (the 2) of the passenger | crew detection method which concerns on this invention. It is a sequence diagram which shows the procedure of embodiment (the 3) of the passenger | crew detection method which concerns on this invention. It is a flowchart which shows the process which controls a safety device.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a main configuration of an embodiment of an occupant detection device. 1 includes a control device 1, a seat heater 2, an ammeter 3, a voltmeter 4, a temperature detector 51, a vehicle speed sensor 52, a drive circuit 6, a switch 7, a safety device 8, a power supply 9, and an operation. A switch 10 is provided.

  The seat heater 2 is provided in a seat in the passenger compartment and generates heat when a current is applied. The ammeter 3 measures the value of the current supplied from the power source 9 to the seat heater 2. The voltmeter 4 measures the value of the voltage applied to the seat heater 2 from the power source 9 and gives it to the control device 1. Instead of the measurement by the voltmeter 4, the output of the power source 9 may be measured by a voltmeter built in the control device 1.

  The operation switch 10 is supplied with an energization start instruction and an energization stop instruction to the seat heater 2 by the operator. An instruction relating to the temperature setting of the seat heater 2 may be input from the operation switch 10. An instruction input to the operation switch 10 is given to the control device 1.

  The temperature detector 51 measures the temperature in the passenger compartment and gives it to the control device 1. The vehicle speed sensor 52 detects the speed of the vehicle and gives it to the control device 1. The drive circuit 6 switches the switch 7 on and off by a control signal from the control device 1 based on an input to the operation switch 10. The switch 7 turns on or off energization from the power source 9 to the seat heater 2.

  The safety device 8 is a device for ensuring the safety of an occupant such as a seat belt wearing warning light and an airbag, for example. The power source 9 supplies power to the seat heater 2. The power source 9 is, for example, an in-vehicle battery and / or an in-vehicle generator.

  The control device 1 determines whether there is an occupant in the seat based on the current value measured by the ammeter 3. More specifically, for example, when a value related to the current value is included in a predetermined determination range, it is considered that there is an occupant in the seat. The determination result is given to the safety device 8. When determining the presence or absence of an occupant, a signal from at least one of the voltmeter 4 and the temperature detector 51 may be used.

  The control device 1 includes a timer unit 11, a current difference detection unit 12, a control unit 13, a storage unit 14, and a safety device control unit 15.

  The timer unit 11 measures an elapsed time from a predetermined time point. The timer unit 11 is, for example, a counter clock circuit. The timer unit 11 may also be a means for detecting an event that occurs at a predetermined time, for example.

  The current difference detection unit 12 acquires the current value at the first time point and the current value at the second time point from the ammeter 3 and calculates the difference between these two current values. The first time point and the second time point are when the first time and the second time have elapsed since the start of energization from the power source 9 to the seat heater 2, respectively. These time points are discriminated by the time counting of the time measuring unit 11. The first time point may be the start of energization of the seat heater 2. Thereby, the time measuring part 11 does not need to time the first time. In addition, by setting the first time point before the start of energization to the seat heater 2, the current difference detection unit 12 does not need to acquire the current value at the first time point.

  The storage unit 14 stores information related to one or more determination ranges. The information related to the determination range stored in the storage unit 14 is information related to a range of values determined to determine that there is an occupant in the seat. More specifically, for example, the information is related to the range of the difference between the current value at the first time point and the current value at the second time point.

  The information related to the determination range may be associated with a different determination range for each temperature range in the passenger compartment. Thereby, for example, the control unit 13 acquires information relating to different determination ranges depending on whether the temperature in the vehicle compartment is high or low.

  The information related to the determination range may be associated with a different determination range for each voltage value range of the power supply 9. Thereby, for example, the control unit 13 acquires information related to different determination ranges depending on whether the voltage value of the power supply 9 is high or low.

  The control unit 13 determines whether there is an occupant in the seat based on the difference calculated by the current difference detection unit 12. First, the control unit 13 acquires information related to the determination range of the current value that determines that there is an occupant in the seat from the storage unit 14, and performs determination based on this information.

  More specifically, the control unit 13 acquires information related to a determination range between the current value at the first time point and the current value at the second time point from the storage unit 14. The control unit 13 compares the calculated difference with the determination range, and determines whether or not the current value difference is included in the determination range. Here, when it is included in the determination range, it is considered that there is a passenger in the seat related to the difference.

  Moreover, the control part 13 acquires the information which concerns on the determination range corresponding to the temperature from the memory | storage part 14, when the information of the temperature in the vehicle interior which the temperature detector 51 detected is given. In addition, when the control unit 13 receives information on the voltage value of the voltage applied from the voltmeter 4 to the seat heater 2 from the voltmeter 4, the control unit 13 displays information on the determination range corresponding to the voltage value. Obtained from the storage unit 14.

  The control unit 13 is given a signal from the vehicle speed sensor 52 that the vehicle has started to travel. The control unit 13 is also given an energization start instruction signal and an energization stop instruction signal from the operation switch 10 to the seat heater 2.

  When the vehicle is not traveling, the control unit 13 starts energization of the seat heater 2 by an energization start instruction given from the operation switch 10. In addition, when the vehicle starts running without an instruction to start energization from the operation switch 10 to the seat heater 2, the control unit 13, regardless of whether there is an instruction to start energization from the operation switch 10. Energization of the seat heater 2 is started.

  Note that the energization of the seat heater 2 is performed with a constant voltage for a predetermined period after the energization of the seat heater 2 is started. Thereby, the presence or absence of the passenger | crew by the change of an electric current value can be detected accurately.

  The safety device control unit 15 gives the safety device 8 control signals that can be operated and cannot be operated. When the control unit 13 determines that the difference in the current value is included in the determination range, the safety device control unit 15 provides the safety device 8 with a control signal that enables the safety device 8 to operate. The safety device control unit 15 also provides the safety device 8 with a control signal that disables the safety device 8 when the control unit 13 determines that the difference in current value is not included in the determination range. Also good.

  The safety device control unit 15 may be configured as one unit together with the control unit 13.

  FIG. 2 is a graph showing an example of a change in the current value supplied to the seat heater 2. In FIG. 2, the vertical axis represents the current value energized to the seat heater, and the horizontal axis represents the elapsed time from the start of energization. The case where there is no occupant in the seat where the seat heater 2 is provided is plotted with a black square in the figure, and the case where there is an occupant is plotted with ▲ in the figure.

  From FIG. 2, the current value applied to the seat heater 2 is different between when the occupant is present and when the occupant is not present, and the current value is greater than when the occupant is present and absent. This is because when there is no occupant, the temperature of the seat heater 2 is likely to rise, and the resistance is proportional to the temperature, so that it is difficult for current to flow.

  In the present embodiment, the first time point relative to the start of energization is the start of energization. The start of energization is notified to the control device 1 by an input from the operation switch 10. The ammeter 3 may detect the start of energization. Thereby, it is possible to simultaneously realize that the control device 1 acquires the current value at that time from the ammeter 3.

  FIG. 3 is a flowchart showing an outline of the procedure of the first embodiment of the occupant detection method. The process of FIG. 3 is started simultaneously with the start of energization of the seat heater 2. First, the current difference detection unit 12 detects a difference in current value at two different times with respect to the start of energization of the seat heater 2 (step S101). Next, the control part 13 acquires the information which concerns on the determination range from the memory | storage part 14 (step S102). The control unit 13 determines whether or not the difference between the current values is included in the determination range, and the safety device control unit 15 performs control to switch between enabling / disabling of the safety device 8 (step S103).

  FIG. 4 is a flowchart illustrating an example of a processing procedure for detecting a difference in current values. The process of FIG. 4 is executed by the current difference detection unit 12. First, energization from the power source 9 to the seat heater 2 is started. At the same time, the current difference detection unit 12 acquires the current value (1) detected by the ammeter 3 (step S11).

  The timer unit 11 determines whether or not it is the second time point relative to the start of energization (step S12). The second time point is a time point when a predetermined time has elapsed from the start of energization of the seat heater 2. If it is not the second time point (step S12: NO), it waits until it reaches the second time point. In the case of the second time point (step S12: YES), the current difference detection unit 12 acquires the current value (2) detected by the ammeter 3 (step S13).

  The current difference detection unit 12 calculates a difference between the current value (1) acquired at the start of energization of the heater and the current value (2) acquired at the second time point (step S14).

  After the difference is calculated, the processing returns to FIG.

  FIG. 5 is a flowchart showing a process for controlling the safety device. The processing in FIG. 5 is started following step S102 in FIG.

  First, the control unit 13 determines whether or not the difference detected by the current difference detection unit 12 is included in the determination range based on the determination range information acquired from the storage unit 14 (step S31). When it is included in the determination range (step S31: YES), it is considered that there is an occupant, and the safety device control unit 15 outputs an operation enable signal to the safety device (step S32).

  On the other hand, when the difference calculated by the current difference detection unit 12 is not included in the determination range (step S31: NO), it is considered that there is no passenger, and the safety device control unit 15 operates on the safety device 8. A disabled signal is output (step S33).

  With the above processing, the presence or absence of an occupant is determined based on the difference between the current values and the determination range. Thereby, the safety device control part 15 can perform control which switches operation | movement enabling / disabling with respect to a safety device.

  FIG. 6 is a flowchart showing the procedure of the passenger detection method (part 2). In FIG. 5, processing including correction for the interior temperature of the passenger compartment or the power supply voltage is performed.

  Since step S201 and step S203 of FIG. 6 are the same as the process of step S101 and step S103 of FIG. 3, respectively, description is abbreviate | omitted here.

  After the difference in current value is detected in step S201, or before or after the detection of the difference in current value, the control unit 13 enters a determination range corresponding to the room temperature in the vehicle interior or the value of the power supply voltage. Such information is acquired (step S202).

  Here, the determination range corresponding to the room temperature or the power supply voltage is used, but the embodiment of the present invention is not limited to this example. For example, the calculated difference may be corrected in accordance with the room temperature or the power supply voltage, and the difference may be used in step S203 to determine whether or not it is included in the determination range.

(Second Embodiment)
FIG. 7 is a block diagram illustrating a main configuration of the occupant detection device according to the embodiment. The occupant detection device of FIG. 7 detects the current value of the seat heater provided for each seat provided in the vehicle, and performs control to switch between enabling / disabling of safety devices provided in seats other than the driver's seat. . 7 includes a control device 1a, a seat heater 2a, a seat heater 2b, an ammeter 3a, an ammeter 3b, a drive circuit 6a, a drive circuit 6b, a temperature detector 51, a vehicle speed sensor 52, a voltmeter 4, and a switch. 7a, a switch 7b, a safety device 8a, a safety device 8b, a power source 9, and an operation switch 10.

  In the occupant detection device of FIG. 7, each part having the same function and configuration as the occupant detection device of FIG. 1 is denoted by the same reference numeral, and description thereof is omitted here.

  In the present embodiment, the seat heater 2a is provided in the driver seat, and the seat heater 2b is provided in the passenger seat. The ammeter 3a measures the current value related to the seat heater 2a, and the ammeter 3b measures the current value related to the seat heater 2b. The switch 7a switches energization to the seat heater 2a on and off, and the drive circuit 6a controls the switch 7a. The switch 7b switches on / off of energization to the seat heater 2b, and the drive circuit 6b controls the switch 7b.

  The safety device related to the driver's seat provided with the seat heater 2a is the safety device 8a, and the safety device related to the passenger seat provided with the seat heater 2b is the safety device 8b.

  The control device 1a includes a timer unit 11, a current difference detection unit 12a, a control unit 13a, a storage unit 14a, and a safety device control unit 15a.

  The current difference detection unit 12a acquires the current values of the seat heater 2a and the seat heater 2b, and calculates the difference between the current value supplied to the seat heater 2a and the current value supplied to the seat heater 2b. The current difference detection unit 12a may calculate the difference between the current value to the seat heater 2a and the current value to the seat heater 2b at the same time. The current difference detection unit 12a also includes a current value at the time when the first time has elapsed from the start of energization to the seat heater 2a, and a current value at the time when the first time has elapsed from the start of energization to the seat heater 2b. The difference may be calculated.

  The storage unit 14a stores information related to one or more determination ranges. The information stored in the storage unit 14 is information related to a range of values determined to have an occupant in the seat, and is related to a range of a difference between the current value of the driver's seat and the current value of another seat different from the driver's seat. Information.

  The control unit 13a acquires information related to the determination range of the difference between the current value of the driver's seat and the current value of another seat different from the driver's seat from the storage unit 14a. The control unit 13a compares the difference calculated by the current difference detection unit 12a with the determination range. When the difference in current value is included in the determination range, it is considered that there are passengers in the seats related to the difference.

  Moreover, the control part 13 acquires the information which concerns on the determination range corresponding to the temperature from the memory | storage part 14, when the information of the temperature in the vehicle interior which the temperature detector 51 detected is given. In addition, when the control unit 13 is provided with information on the voltage value of the voltage applied from the voltmeter 4 to the seat heater 2a and the seat heater 2b by the power source 9, the determination range corresponding to the voltage value is given. Is obtained from the storage unit 14.

  The control unit 13 is given a signal from the vehicle speed sensor 52 that the vehicle has started to travel. The control unit 13 is also supplied with an energization start instruction signal and an energization stop instruction signal from the operation switch 10 to the seat heater 2a and the seat heater 2b.

  When the vehicle is not traveling, the control unit 13 starts energizing each of the seat heater 2a and the seat heater 2b according to the energization start instruction for each seat heater given from the operation switch 10. The control unit 13 also determines whether or not there is an instruction to start energization from the operation switch 10 when the vehicle starts traveling without being given an instruction to start energization from the operation switch 10 to the seat heater 2a and the seat heater 2b. Regardless, the energization of the seat heater 2 is started.

  Note that the energization of the seat heater 2 is performed with a constant voltage for a predetermined period after the energization of the seat heater 2 is started. Thereby, the presence or absence of the passenger | crew by the change of an electric current value can be detected accurately.

  The safety device control unit 15a gives a control signal indicating whether the operation is possible or not, to the safety device 8a and the safety device 8b. When the control unit 13a determines that the difference in the current value is included in the determination range, the safety device control unit 15a gives an operation control signal to the safety device 8b. The safety device control unit 15a may also provide an operation disable control signal to the safety device 8b when the control unit 13a determines that the difference in current value is not included in the determination range.

  Note that the safety device control unit 15a may give a control signal to the safety device 8a to enable the safety device 8a when the vehicle is in operation, regardless of the determination of the control unit 13a.

  FIG. 8 is a sequence diagram showing a procedure of the second embodiment of the occupant detection method. In FIG. 8, the presence or absence of a passenger in the passenger seat is detected based on the difference in the current value of the seat heater between the driver seat and the passenger seat.

  The process of FIG. 8 is started simultaneously with the start of energization of the seat heater 2a. First, the operation switch 10 notifies the control unit 13a that energization is started for the seat heater 2a in the driver's seat (step S301). Based on this notification, the control unit 13a controls the drive circuit 6a to operate the switch 7a and start energization to the seat heater 2a. An instruction to start timing is given from the control unit 13a to the timing unit 11 (step S302).

  The operation switch 10 notifies the control unit 13a that energization is started to the seat heater 2b in the passenger seat (step S303). Based on this notification, the control unit 13a controls the drive circuit 6b to operate the switch 7b, and starts energization to the seat heater 2b. An instruction to start timing is given from the control unit 13a to the timing unit 11 (step S304).

  The timing unit 11 notifies the current difference detection unit 12a that the second time point has been reached when the energization of the seat heater 2a in the driver's seat is started (step S305). The current value of the seat heater 2a is requested from the current difference detector 12a to the ammeter 3a (step S306). Based on this request, the current value measured by the ammeter 3a is given to the current difference detector 12a (step S307).

  The time measuring unit 11 notifies the current difference detecting unit 12a that the second time point has been reached when the energization of the seat heater 2b in the front passenger seat is started (step S308). The current difference detection unit 12a requests the ammeter 3b for the current value of the seat heater 2b (step S309). Based on this request, the current value measured by the ammeter 3b is given to the current difference detector 12a (step S310).

  The current difference detection unit 12a calculates the difference between the current value of the seat heater 2a and the current value of the seat heater 2b (step S311). The difference between the calculated current values is notified from the current difference detection unit 12a to the control unit 13a (step S312).

  Before and after the processing from step S301 to step S312, the control unit 13a acquires information related to the determination range from the storage unit 14 (step S313). This information is information for determining the presence or absence of a passenger in a seat different from the driver seat based on the difference between the current value of the driver seat and the current value of a seat different from the driver seat.

  The control unit 13a and the safety device control unit 15a perform a process related to the control of the safety device for the passenger seat using the difference between the given current values and the acquired information on the determination range (step S314). The procedure of this process is the same as the procedure of the flowchart shown in FIG.

(Third embodiment)
The occupant detection device according to the present embodiment has the configuration shown in FIG. However, part of the operation of each part constituting the occupant detection device is different from that of the second embodiment. Here, each part different in action from the second embodiment will be described.

  The current difference detection unit 12a acquires the current value at the second time point when the energization starts and when the seat heater 2a starts energizing, and calculates the difference therebetween. The current difference detection unit 12a also obtains current values at the second time point when the energization starts and when the seat heater 2b starts energization, and calculates the difference therebetween. The current difference detector 12a further calculates the difference between the two calculated differences.

  The storage unit 14a stores information related to one or more determination ranges. The information stored in the storage unit 14a is information related to a range of values determined to have a passenger in the seat, and the difference between the difference in the current value of the driver's seat and the difference in the current value of another seat different from the driver's seat It is the information concerning the range.

  The control unit 13a acquires, from the storage unit 14a, information related to the range of the difference between the current value difference of the driver seat and the current value difference of another seat different from the driver seat. The control unit 13a compares the difference calculated by the current difference detection unit 12a with the determination range. When the difference is included in the judgment range, it is considered that there is a passenger in the seat related to the difference.

  FIG. 9 is a sequence diagram showing a procedure of the embodiment (part 3) of the occupant detection method. The process of FIG. 9 is started simultaneously with the start of energization of the seat heater 2a. First, a notification that the energization of the seat heater 2a has been started is given from the operation switch 10 to the control unit 13a (step S401). An instruction to start timing is given from the control unit 13a to the timing unit 11 (step S402).

  The control unit 13a notifies the current difference detection unit 12a that energization of the seat heater 2a has started (step S403). The current difference detector 12a requests the ammeter 3a for the current value (1) of the seat heater 2a (step S404). Based on this request, the current difference detection unit 12a acquires the current value (1) of the seat heater 2a from the ammeter 3a (step S405).

  The operation switch 10 notifies the control unit 13a that the energization of the seat heater 2b has been started (step S406). An instruction to start timing is given from the control unit 13a to the timing unit 11 (step S407).

  The control unit 13a notifies the current difference detection unit 12a that the energization of the seat heater 2b has been started (step S408). The current difference detection unit 12a requests the ammeter 3b for the current value (1) of the seat heater 2b (step S409). Based on this request, the current difference detection unit 12a acquires the current value (1) of the seat heater 2b from the ammeter 3b (step S410).

  The timer 11 notifies the current difference detector 12a that the second time point has been reached when the energization of the seat heater 2a is started (step S411). The current difference detector 12a requests the ammeter 3a for the current value (2) of the seat heater 2a (step S412). Based on this request, the current difference detection unit 12a acquires the current value (2) of the seat heater 2a from the ammeter 3a (step S413).

  The timer 11 notifies the current difference detector 12a that the second time has been reached when the energization of the seat heater 2b is started (step S414). The current difference detector 12a requests the ammeter 3b for the current value (2) of the seat heater 2b (step S415). Based on this request, the current difference detection unit 12a acquires the current value (2) of the seat heater 2b from the ammeter 3b (step S416).

  The current difference detector 12a calculates the difference between the current value (1) and the current value (2) of the seat heater 2a and the difference between the current value (1) and the current value (2) of the seat heater 2b, Further, the difference between the two differences is calculated (step S417). The difference difference calculated is notified from the current difference detection unit 12a to the control unit 13a (step S418).

  Before and after Step S401 to Step S418, the control unit 13a acquires information related to the determination range from the storage unit 14a (Step S419). This information is information related to the determination range of the difference between the difference in the current value of the driver's seat and the difference in the current value of the seat different from the driver's seat.

  A process (2) in which the control unit 13a and the safety device control unit 15a control the safety device of the front passenger seat using the given difference and the information related to the determination range acquired from the storage unit 14a. This is performed (step S420).

  FIG. 10 is a flowchart showing a process for controlling the safety device. The process of FIG. 10 includes a process of detecting the presence or absence of an occupant in another seat based on the difference between the current values of the driver's seat and the current value of the other seat.

  Based on the determination range information acquired from the storage unit 14, the control unit 13a determines whether the difference between the current value in the driver seat calculated by the current difference detection unit 12 and the difference in current value in the passenger seat is determined. It is determined whether it is included in the range (step S81). If it is included in the determination range (step S81: YES), the safety device control unit 15 performs control to enable the passenger seat safety device to operate, assuming that there is a passenger in the passenger seat (step S82).

  On the other hand, when it is not included in the determination range (step S81: NO), the control unit 13a considers that there is no occupant, and the safety device control unit 15 performs control so that the safety device does not operate (step S83).

  After the safety device control unit 15 performs control to switch between enabling / disabling of the safety device, the process returns to FIG.

  The “determination unit” described in the claims corresponds to the “control unit”. The “signal output unit” corresponds to the “safety device control unit”.

  As mentioned above, although the form for inventing was demonstrated, this invention is not limited to embodiment described in the form for implementing this invention. Modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Control apparatus 10 Operation switch 11 Timing part 12, 12a Current difference detection part 13, 13a Control part (determination part)
14, 14a Storage unit 15, 15a Safety device control unit (signal output unit)
DESCRIPTION OF SYMBOLS 1a Control device 2, 2a, 2b Seat heater 3, 3a, 3b Ammeter 4 Voltmeter 51 Temperature detector 52 Vehicle speed sensor 6 Drive circuit 7 Switch 8, 8a, 8b Safety device 9 Power supply

Claims (8)

In an occupant detection device that detects the presence or absence of an occupant of a vehicle including a seat provided with a heater that generates heat by electric power,
A current difference detection unit for detecting a difference between current values supplied to the heater at two different predetermined time points;
A determination unit that determines whether or not the difference detected by the current difference detection unit is included in a predetermined determination range;
An occupant detection device comprising: a signal output unit that outputs a predetermined signal when the determination unit determines that the difference is included in the determination range.   The occupant detection device according to claim 1, further comprising a storage unit that stores information related to the determination range. It has a temperature detector that detects the temperature in the passenger compartment,
The storage unit stores information related to the determination range corresponding to each of a plurality of temperatures in the vehicle interior,
The said determination part is comprised so that the information which concerns on the determination range corresponding to the temperature in the vehicle interior which the said temperature detector detected may be acquired from the said memory | storage part. apparatus. A voltage detection unit for detecting a voltage applied to the heater;
The storage unit stores information on the determination range corresponding to each of a plurality of voltages,
The occupant detection device according to claim 2 or 3, wherein the determination unit is configured to acquire information related to a determination range corresponding to the voltage detected by the voltage detection unit from the storage unit. .   5. One of the two predetermined time points is a start time of energization of the heater, and the other time point is after the start of energization. 6. Occupant detection device. In an occupant detection device that detects the presence or absence of an occupant of a vehicle provided with a heater that generates heat by electric power in each of a plurality of seats including a driver's seat,
A current difference detection unit for detecting a difference between current values supplied to the heater at two predetermined time points different for each heater;
The difference between the difference detected by the current difference detector of the heater provided in a seat different from the driver seat and the difference detected by the current difference detector of the heater provided in the driver seat is a predetermined determination range. A determination unit for determining whether or not included in,
An occupant detection device comprising: a signal output unit that outputs a predetermined signal when the determination unit determines that the difference is included in the determination range. In an occupant detection device that detects the presence or absence of an occupant of a vehicle including a heater that is heated by electric power in each of a plurality of seats including a driver's seat,
The current value energized to the heater of the driver seat at a predetermined time after the start of energization of the heater of the driver seat and the heater of the seat at a predetermined time after the start of energization of the heater of the seat different from the driver seat A current difference detection unit for detecting a difference from the energized current value;
A determination unit that determines whether or not the difference detected by the current difference detection unit is included in a predetermined determination range;
An occupant detection device comprising: a signal output unit that outputs a predetermined signal when the determination unit determines that the difference is included in the determination range. In a method for detecting the presence or absence of a vehicle occupant having a seat provided with a heater that generates heat by electric power,
Detecting a difference between current values supplied to the heater at two different predetermined time points;
Determining whether the difference detected in the step is included in a predetermined determination range;
And a step of outputting a predetermined signal when the determination unit determines that the difference is included in the determination range.

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