JP5200632B2 - Remote control system for vehicles - Google Patents

Description

  The present invention relates to a vehicular remote control system in which a vehicle-mounted device performs predetermined control when a wireless signal is transmitted from a portable device carried by a user to the vehicle-mounted device.

2. Description of the Related Art Conventionally, in the field of automobile-related technology, a vehicle remote control system including an in-vehicle device mounted on a vehicle and a portable device possessed by a vehicle user has been put into practical use.
This type of vehicular remote control system can be used to lock / unlock doors remotely by operating a portable device at a location away from the vehicle, even without using mechanical keys in the vicinity of the vehicle. It is a mechanism that can execute control such as engine start (so-called remote keyless entry system).

  Even if the user does not operate the portable device, if the portable device exists in the wireless communication area near the vehicle, authentication by wireless communication is performed, and various controls are executed when the authentication is established. There is also a system (so-called smart entry system).

Furthermore, in this type of vehicle remote control system, a technique for suppressing power consumption in a portable device has also been proposed (for example, see Patent Document 1 below). In the technology described in Patent Document 1, power consumption is suppressed by stopping or restarting the reception operation of the portable device (see Patent Document 1: claims 6, 7, etc.).
Japanese Patent Laid-Open No. 11-71948

  By the way, in this type of vehicle remote control system, if the remaining battery level of the portable device decreases excessively, the system cannot function normally. It is necessary to replace the battery. Therefore, it is effective to employ a mechanism for notifying the user when such battery replacement is necessary.

  However, the battery built in this type of portable device has a characteristic that the battery voltage is drastically reduced as the remaining battery level is reduced. Therefore, even if the period from the time when it is estimated that the battery needs to be replaced to the time when it will no longer function effectively as a battery is extremely short, There was a risk that the battery would run out without noticing.

  Here, it is considered that the power saving technique described in Patent Document 1 is also effective in view of simply extending the battery life. However, with this technology, power consumption is only suppressed during the period when the operation (reception operation) of the portable device is stopped, and power consumption is not suppressed if the operation of the portable device is resumed.

  Therefore, if the operation of the portable device resumes when the remaining battery level is low, the battery voltage will suddenly decrease. This makes it impossible to notice that the remaining battery level is low. There was a risk of cutting.

  The present invention has been made in order to solve the above-described problem, and its purpose is to extend the period during which the user can be notified of this when the battery needs to be replaced. The object is to provide a remote control system for a vehicle.

Hereinafter, the configuration employed in the present invention will be described.
In the vehicular remote control system of the present invention , the detection means detects the remaining level of the battery built in the portable device, and when the detected remaining level falls below a predetermined switching reference, the transmission output switching means Switches the radio signal transmission output to a lower output.

  Here, switching to a lower output means that switching is performed such that the output after switching is relatively lower before and after switching. Therefore, if such switching is performed, the power consumption of the portable device is suppressed after switching compared to before switching, thereby preventing a sudden drop in battery voltage.

Moreover, the remaining amount level detected by the detecting unit is transmitted to the in-vehicle device by a radio signal, and the in-vehicle device is based on the data indicating the remaining level included in the wireless signal received by the receiving unit. Thus, information on the remaining amount level is notified to the user. Specifically, based on the data indicating the remaining amount level, the notifying unit switches the plurality of notification modes step by step until the remaining amount level is lower than the switching reference, so that the level reduction state is indicated. When the remaining amount level is lower than the switching reference, the user is notified that the transmission output has been switched by further switching the notification mode.

Therefore, the user can detect over a plurality of stages that the remaining battery level of the portable device is reduced by the information notified by the notification means. In particular, as described above, since the power consumption of the portable device is suppressed, the period in which communication between the portable device and the in-vehicle device can be performed is longer than before. The period during which the notification can be made can be extended from the conventional time.

  Therefore, it is possible to increase the opportunity for the user to notice the situation where the battery of the portable device is likely to run out, and the user can take necessary measures such as replacing the battery, so that the system can function normally. Users will be able to prevent them from falling into an incapable state.

In the vehicle remote control system of the present invention , two or more switching criteria may be set as the predetermined switching criteria. In this case, the transmission output switching unit may switch the transmission output of the radio signal to a low output every time the remaining amount level detected by the detection unit is lower than each switching reference. That is, in this case, the transmission output of the radio signal is sequentially switched to a low output over three stages or more.

  Further, the notification means may notify the information regarding the remaining amount level in any notification mode. For example, the notification means (a warning light or a display capable of displaying a graphic), an auditory notification means (buzzer or Message voice) and the like can be arbitrarily adopted, and these can be used together.

In the case of a warning light, you can inform the remaining level of three ways in the off lights / flashing / Steady. Further, by changing the blinking pattern, four or more remaining levels can be notified, and by changing the lighting color, a plurality of remaining levels can be notified. If it is a display capable of graphic display, it is only necessary to display a symbol corresponding to each of a plurality of remaining amount levels. Also in the case of a buzzer, a plurality of remaining levels can be notified by a tone or ringing pattern, and in the case of a message voice, a specific warning content can be messaged.

In the vehicle remote control system of the present invention , the transmission means switches the transmission output as data indicating the remaining level when the transmission output switching means switches the transmission output of the radio signal to a lower output. A wireless signal including data that can be determined on the in-vehicle device side is transmitted to the in-vehicle device. Then, the notification means notifies the user that the transmission output has been switched by further switching the notification mode when the remaining level falls below the switching reference based on the data indicating the remaining level. .

  Therefore, when the transmission output switching unit switches the transmission output of the radio signal to a lower output, the user can immediately recognize this, and the battery can be replaced at a more appropriate timing.

By the way, in the vehicle remote control system of the present invention , the transmission output switching means stores the information when the transmission output is switched at the time of operation, and before starting the transmission of the radio signal at the next operation, switching the transmission output to the same output as when storing the information, it may be configured that.

By adopting a configuration as this, prevention despite switching the transmission output in a low output in the past, transmission output when operating next is from being returned to the high output side is the initial value in advance it can. Therefore, it can suppress that a portable machine falls into battery remaining shortage due to the transmission output returning to the high output side which is an initial value.

In the case of the vehicle remote control system of the present invention , in the portable device, the transmission stop control means stops the transmission of the radio signal when the remaining amount level detected by the detection means falls below a predetermined stop reference . It may be configured as .

By performing the control such as this, despite the remaining amount level is excessively lowered, unlike what not stop the transmission of the radio signal, the radio in an unstable state where the remaining amount level is excessively lowered Signals are not transmitted, and therefore errors such as bit dropping or bit corruption of radio signals can be prevented, and unnecessary troubles caused by such errors can be avoided.

Next, embodiments of the present invention will be described with some specific examples.
(1) First Embodiment [Configuration of Remote Control System for Vehicle]
The vehicle remote control system described below has a function (so-called remote keyless entry function) in which an in-vehicle device executes predetermined control (for example, door lock / unlock control) in response to a button operation on a portable device, When the portable device enters the wireless communication area around the vehicle, the vehicle-mounted device also has a function (so-called smart entry function) for executing predetermined control (for example, door unlock control).

FIG. 1 is a block diagram showing a configuration of a vehicle remote control system. This vehicular remote control system includes an in-vehicle device 1 and a portable device 2 mounted on a vehicle.
Among these, the vehicle-mounted device 1 includes a control unit 11, a transmission unit 12, a reception unit 13, a display unit 14, and the like.

  The control unit 11 is a well-known device mainly composed of a microcomputer including a CPU, a ROM, a RAM, and the like. Under the control of the control unit 11, the transmission unit 12, the reception unit 13, and the display unit 14. Etc. work.

  The transmitter 12 is prepared for the smart entry function, and is a means for transmitting a radio signal to the portable device 2 using radio waves in the LF (Low Frequency) band. The radio signal transmitted from the transmission unit 12 reaches only within a limited communication area in the vicinity of each antenna via a plurality of antennas distributed at specific positions of the vehicle.

The receiving unit 13 is a means for receiving a radio signal transmitted from the portable device 2 using radio waves in an RF (Radio Frequency) band.
The display unit 14 functions as a notification unit in the present invention. In the present embodiment, a display called a multi-information display capable of displaying various types of information about the vehicle is used, and the remaining battery level of the portable device 2 is used. Information is displayed.

  On the other hand, the portable device 2 includes a control unit 21, a reception unit 22, a transmission unit 23, a battery unit 24, a battery voltage level detection unit 25, a transmission power switching unit 26, a storage unit 27, push switches 28 and 29, and the like. .

  The control unit 21 is configured mainly with a microcomputer in which a CPU, ROM, RAM, and the like are incorporated on an LSI chip. Under the control of the control unit 21, the reception unit 22, the transmission unit 23, and the battery unit 24. The battery voltage level detection unit 25, the transmission power switching unit 26, the storage unit 27, and the like function.

  The receiving unit 22 is prepared for the smart entry function, and is a means for receiving a radio signal transmitted from the vehicle-mounted device 1 using an LF band radio wave. The transmission unit 23 is a means for transmitting a radio signal to the in-vehicle device 1 using an RF band radio wave.

  The battery unit 24 is means for supplying power to each unit of the portable device 2, and the battery voltage level detection unit 25 detects the remaining level of the battery unit 24. That is, in this embodiment, the battery voltage level detection unit 25 detects the remaining level of the battery unit 24 based on the voltage. The transmission power switching unit 26 is a circuit that switches the transmission power in the transmission unit 23 to either a standard state or a low power state lower than the standard state.

  The storage unit 27 is a storage device provided to store information necessary for the control unit 21 to perform various controls. A part of the storage unit 27 is configured by a non-volatile memory, such as battery replacement. The stored contents can be retained.

  The push switches 28 and 29 are prepared as keys serving as triggers for using the remote keyless entry function. Although the specific operation method of the push switches 28 and 29 is arbitrary, in the case of this embodiment, the door is locked when the push switch 28 is operated by one push. Further, when the push switch 29 is operated by one push, the door is unlocked.

[Characteristics of battery part and display on vehicle]
Next, the relationship between the characteristics of the battery unit 24 and the display on the display unit 14 in the in-vehicle device 1 will be described. FIG. 2A is a graph showing the characteristics of the battery unit 24.

  The portable device 2 performs a normal operation when the remaining amount of the battery unit 24 is sufficiently large, and a current I1 is extracted from the battery unit 24 during the normal operation. At this time, if the state where the current I1 is taken out continues, the voltage V of the battery unit 24 changes from the initial voltage V0 to V1 as the discharge depth D of the battery unit 24 progresses from the initial state as D1 → D2 → D3. → V2 → V3.

  Here, if the battery voltage V may be further lower than the voltage V3, the wireless signal transmission function of the portable device 2 such as bit dropping or bit corruption of the wireless signal transmitted from the portable device 2 occurs. There is an increased risk that will not work properly. Therefore, in this portable device 2, when the battery voltage V reaches the voltage V3, control is performed to stop the wireless signal transmission function.

  However, simply by stopping the wireless signal transmission function when the battery voltage V reaches the voltage V3, the mobile device 2 suddenly uses the battery unit 24 without noticing that the battery unit 24 is out of battery power (insufficient charge). Since it will be in the state which cannot be performed, in order to prevent this, the vehicle equipment 1 displays the remaining amount of the battery unit 24.

  Specifically, as shown in FIGS. 2B and 2C, when the battery voltage V is equal to or higher than a predetermined voltage V1 (V1 ≦ V), the display unit 14 included in the in-vehicle device 1 includes a battery The remaining amount display (1) is displayed. Further, when the battery voltage V is lower than the predetermined voltage V1, if the voltage is equal to or higher than the predetermined voltage V2 (V2 ≦ V <V1), the battery remaining amount display (2) is displayed on the display unit 14 included in the in-vehicle device 1. Is displayed. Therefore, if the battery remaining amount display (2) is displayed on the display unit 14, the user can recognize that the battery replacement time is approaching.

  Further, when the battery voltage V is lower than the predetermined voltage V2, if the voltage is equal to or higher than the predetermined voltage V3 (V3 ≦ V <V2), the battery remaining amount display (3) is displayed on the display unit 14 included in the in-vehicle device 1. Is displayed. This battery remaining amount display (3) is a display indicating that the battery needs to be replaced, and the user who has seen this battery remaining amount display (3) can quickly recognize that the battery needs to be replaced. .

  Incidentally, when the battery voltage V falls below the predetermined voltage V3 (V <V3), as described above, the portable device 2 is controlled to stop the wireless signal transmission function. 2 is not transmitted to the vehicle-mounted device 1. Therefore, the display unit 14 included in the in-vehicle device 1 is in a state where no display regarding the remaining battery level is made.

  By the way, when information on the remaining battery level is displayed on the display unit 14 included in the in-vehicle device 1 by the above-described method, if the user looks at the display content of the display unit 14, the battery unit 24 runs out of battery (remaining level). It is considered that the battery needs to be replaced.

  However, the battery voltage display (3) is displayed during the period in which the battery charge display (3) is displayed, because the battery voltage has a characteristic of rapidly decreasing compared to other periods when the battery charge is higher. Tend to be short-term. Therefore, if the user misses the battery remaining amount display (3) during this short period, the battery voltage V falls below the voltage V3, and the portable device 2 may not function.

  Therefore, in order to cope with such a problem, in the portable device 2, when the battery voltage V is lower than the predetermined voltage V2 (V <V2), the transmission power switching unit 26 is operated to perform transmission. The transmission output by the unit 23 is switched to a lower output.

  As a result, after this transmission power switching, the current I extracted from the battery unit 24 is switched to a current I2 that is smaller than the current I1 during normal operation, and the characteristics of the battery unit 24 are changed as shown in FIG. It switches as shown to (a), and the voltage V of the battery part 24 can maintain the state more than the voltage V3 until the depth of discharge D reaches D4.

  That is, when the state of consuming the current I1 before switching is maintained, the battery voltage drops to V3 when the discharge depth D3 is reached, and then the portable device 2 becomes inoperative, By reducing the current to the current I2, the state of the voltage V3 or higher can be maintained until the discharge depth D4 is reached, and the life of the battery unit 24 can be extended.

  Therefore, since the period during which the battery remaining amount display (3) is further displayed can be extended by this extended life, the opportunity for the user to notice the battery remaining amount display (3) can be increased. Thereby, the possibility that the battery voltage V may fall below the voltage V3 without battery replacement can be reduced.

[Processes executed by in-vehicle devices and portable devices]
Next, in order to implement | achieve the function of the remote control system for vehicles mentioned above, the detail of the process performed in each of the vehicle equipment 1 and the portable device 2 is demonstrated.

  Among the processes described below, the process executed by the portable device 2 is executed when there is an RF transmission request to the control unit 21 included in the portable device 2. This RF transmission request is generated when the user operates the push switches 28 and 29 when the user uses the remote keyless entry function.

  When the smart entry function is used, when the portable device 2 enters a wireless communication area near the vehicle, a wireless signal is transmitted from the in-vehicle device 1 to the portable device 2 using radio waves in the LF band. An RF transmission request is generated in response to reception by the receiving unit 22.

  In this way, when the trigger for generating the RF transmission request is different, there is some difference in the contents of the radio signals specifically exchanged. However, the processing procedure that the portable device 2 will execute after the RF transmission request is generated has no difference due to the difference in the trigger. Therefore, in the following description, the difference in the trigger as described above is not distinguished. I will continue the explanation.

  When the RF transmission request is generated, the portable device 2 starts processing as shown in FIG. When this process is started, the portable device 2 first starts RF transmission (S105). At this point, transmission of a preamble or the like is started, and data transmission is not yet performed. Then, it is determined whether or not the battery voltage V is greater than the predetermined voltage V1 (S110). If it is greater (S110: YES), the battery voltage drop flag is set to “00” (S115) to transmit data. Is started (S120).

  The battery voltage drop flag is 2-bit data, and a data string including the battery voltage drop flag is transmitted in the processing step of S115. Then, it waits for the end of data transmission until the data transmission is completed (S125: NO), and when completed (S125: YES), the process shown in FIG. 3 is terminated.

  On the other hand, when the battery voltage V is equal to or lower than the predetermined voltage V1 (S110: NO), the portable device 2 determines whether or not the battery voltage V is higher than the predetermined voltage V2 (S130). (S130: YES), “01” is set to the battery voltage drop flag (S135), and data transmission is started (S140). Then, it waits for the end of data transmission until the end of data transmission (S145: NO), and when it ends (S145: YES), the process shown in FIG. 3 is ended.

  When the battery voltage V is equal to or lower than the predetermined voltage V2 (S130: NO), the portable device 2 sets “10” in the battery voltage drop flag (S150) and switches the transmission power to low power ( S155). Thereby, the transmission power of the portable device 2 becomes lower than that before switching, and the current taken out from the battery unit 24 is switched from the current I1 shown in FIG. 2A to the current I2.

  The portable device 2 starts data transmission after switching the transmission power (S160). If the battery voltage V exceeds the predetermined voltage V3 (S165: YES), the end of data transmission is awaited (S170: NO).

  If the data transmission is completed in the repetition of S165 to S170 (S170: YES), the process shown in FIG. 3 is terminated. On the other hand, if the battery voltage V becomes equal to or lower than the predetermined voltage V3 during the repetition of S165 to S170 (S165: NO), the process shown in FIG. 3 is terminated without waiting for the end of data transmission.

  Now, when the process as described above is executed in the portable device 2, the process as shown in FIG. 4 is executed in the in-vehicle device 1. This process is a process that is executed when a radio signal from the portable device 2 is received by the RF reception process that is always executed in the in-vehicle device 1.

  When this process is started, the in-vehicle device 1 first verifies whether data has been normally received from the portable device 2 (S205). Then, when the data can be normally received (S205: YES), it is determined whether or not the battery voltage drop flag included in the data string is “00” (S210). If it is “00” (S210: YES). 2), the battery remaining amount display (1) shown in FIG. 2C is displayed on the display unit 14 (S215).

  Then, the function corresponding to the received data is performed (S220), and the process shown in FIG. In the processing step of S220, the function to be implemented will change depending on the contents of the received data, but specific examples include, for example, locking / unlocking the vehicle door, starting the engine, opening / closing the sliding door, etc. Done.

  On the other hand, when the battery voltage drop flag included in the received data string is not “00” (S210: NO), it is determined whether the battery voltage drop flag is “01” (S225), and “01”. If so (S225: YES), the battery remaining amount display (2) shown in FIG. 2C is displayed on the display unit 14 (S230). Then, the function corresponding to the received data is performed (S220), and the process shown in FIG.

  If the battery voltage drop flag included in the received data string is not “01” (S225: NO), it is determined whether the battery voltage drop flag is “10” (S235), and “10”. If so (S235: YES), the battery remaining amount display (3) shown in FIG. 2C is displayed on the display unit 14 (S240). Then, the function corresponding to the received data is performed (S220), and the process shown in FIG.

  If the battery voltage drop flag included in the received data string is not “10” (S235: NO), an error (for example, a failure in the in-vehicle device 1 or the portable device 2 or a communication environment problem) may occur. In this case, the remaining battery level display (4) shown in FIG. 2C is displayed on the display unit 14 (S245). Then, the function corresponding to the received data is performed (S220), and the process shown in FIG.

  By executing the above-described processing by each of the in-vehicle device 1 and the portable device 2, the notification of the remaining battery level can be realized by the remaining battery level displays (1) to (3) as described above. it can.

  In addition, when the remaining battery level is low by the processing step of S155, the battery power is extended by switching the transmission power of the portable device 2 to low power, and the period for displaying the remaining battery level display (3) is extended. can do.

  Therefore, compared with the case where the transmission power is not controlled, the possibility that the user notices the necessity of battery replacement can be increased, and the user can prevent the portable device 2 from being in a non-functional state. Can be prevented.

In addition, when the transmission power becomes low in this way, the distance over which the wireless signal can be transmitted from the portable device 2 to the vehicle-mounted device 1 is shortened, so the communication distance is shortened when the push switches 28 and 29 are operated. There is also a secondary effect that the user can perceive this fact. Therefore, if a user who feels that the response of the push switches 28 and 29 has become awkward, he / she can immediately determine that the cause is a decrease in the remaining battery level.
(2) Second Embodiment Next, a second embodiment will be described. However, the second and subsequent embodiments have the same basic configuration as the first embodiment, and only a part of the configuration is different from the first embodiment. Therefore, in the following description, The difference from the first embodiment will be mainly described. Further, regarding the same configuration as that of the first embodiment in terms of function, the same reference numerals as those used in the first embodiment are used, and the description that overlaps with the first embodiment is omitted. To do.

  In the second embodiment, the processing content in the in-vehicle device 1 is exactly the same as that in the first embodiment, but the processing content in the portable device 2 is different from that in the first embodiment. Therefore, in the second embodiment, processing executed by the portable device 2 will be described with reference to FIG. The process described below is also executed when an RF transmission request is generated in the portable device 2.

  When the RF transmission request is generated, the portable device 2 first reads the battery voltage drop flag from the storage unit 27 (S305). Here, the battery voltage drop flag stored in the storage unit 27 when the portable device 2 is operated last time is read out.

  Then, it is determined whether or not the battery voltage drop flag is “00” (S310). If it is “00” (S310: YES), RF transmission is started (S315), and then data transmission is started (S320). ). That is, in the first embodiment, the battery voltage is detected after the RF transmission is started, whereas in the second embodiment, the battery voltage is not detected at this stage, and only the battery voltage drop flag is seen. It is said.

  Subsequently, the portable device 2 waits for the end of the data transmission until the data transmission is completed (S325: NO), and if completed (S325: YES), is the battery voltage V higher than the predetermined voltage V1 at this stage? It is determined whether or not (S330).

  Here, when the battery voltage V is higher than the predetermined voltage V1 (S330: YES), “00” is set in the battery voltage drop flag, and the information is written in the storage unit 27 (S335). The processing shown in FIG.

  On the other hand, when the battery voltage V is equal to or lower than the predetermined voltage V1 (S330: NO), the portable device 2 determines whether or not the battery voltage V is higher than the predetermined voltage V2 (S340). (S340: YES), “01” is set in the battery voltage drop flag, the information is written in the storage unit 27 (S345), and the process shown in FIG. 5 is terminated.

  If the battery voltage V is equal to or lower than the predetermined voltage V2 (S340: NO), the portable device 2 sets “10” in the battery voltage drop flag and writes the information in the storage unit 27 (S350). Then, the process shown in FIG.

  On the other hand, if the battery voltage drop flag is not “00” in S310 (S310: NO), it is determined whether or not the battery voltage drop flag is “01” (S360). If the battery voltage drop flag is “01” (S360: YES), RF transmission is started (S365), and then data transmission is started (S370).

  Subsequently, the portable device 2 waits for the end of data transmission until the data transmission is completed (S375: NO), and when completed (S375: YES), proceeds to S330. Since the processing steps after S330 have already been described, description thereof is omitted here.

  If the battery voltage drop flag is not “01” in S360 (S360: NO), the transmission power is switched to low power (S380). Thereby, the transmission power of the portable device 2 becomes lower than that before switching, and the current taken out from the battery unit 24 is switched from the current I1 shown in FIG. 2A to the current I2.

  After switching the transmission power, the portable device 2 starts RF transmission (S385), and then starts data transmission (S390). If the battery voltage V exceeds the predetermined voltage V3 (S395: YES), the end of data transmission is awaited (S400: NO).

  Then, when the data transmission is completed in the repetition of S395 to S400 (S400: YES), it is determined whether or not the battery voltage V is larger than the predetermined voltage V1 (S405).

  Here, when the battery voltage V is larger than the predetermined voltage V1 (S405: YES), “01” is set in the battery voltage drop flag, and the information is written in the storage unit 27 (S410). The processing shown in FIG.

  On the other hand, when the battery voltage V is equal to or lower than the predetermined voltage V1 (S405: NO), the battery voltage drop flag is set to “10” and the information is written in the storage unit 27 (S415), as shown in FIG. The process ends.

  If the battery voltage V becomes equal to or lower than the predetermined voltage V3 in the repetition of S395 to S400 (S395: NO), the process shown in FIG. 5 is performed without waiting for the end of data transmission. finish.

  While the portable device 2 executes the processing as described above, the in-vehicle device 1 executes the same processing as in the first embodiment, thereby displaying the remaining battery level (1) to (3) as described above. It is possible to realize notification of the remaining battery level.

  Moreover, when the remaining battery level is low by the processing step of S380, the battery power is extended and the period for displaying the remaining battery level display (3) is extended by switching the transmission power of the portable device 2 to low power. can do.

  Therefore, compared with the case where the transmission power is not controlled, the possibility that the user notices the necessity of battery replacement can be increased, and the user can prevent the portable device 2 from being in a non-functional state. Can be prevented.

In the second embodiment, the battery voltage drop flag is seen in the processing steps of S310 and S360, the transmission power is reduced in S380, and then RF transmission is started in S385, so the first embodiment Unlike the case, the battery voltage V does not fall below the voltage V3 before the transmission power is reduced due to the start of RF transmission. Therefore, the chance that the portable device 2 can function normally can be increased more than the system of the first embodiment.
(3) Third Embodiment Next, a third embodiment will be described. 3rd Embodiment is an example from which the alerting | reporting aspect in the vehicle equipment 1 differs from 1st, 2nd embodiment.

  Specifically, in the first and second embodiments, the in-vehicle device 1 notifies the change in the remaining battery level with the three-stage display based on the remaining battery level displays (1) to (3). In the third embodiment, as shown in FIG. 6 (a) and FIG. 6 (b), only the voltages V2 and V3 are used as thresholds, and the warning lamp is turned off / on, and the battery replacement time is notified. It is set as the structure which performs.

  That is, the battery remaining amount indications (1) to (2) in the first and second embodiments are turned off in the warning light in the third embodiment, and the battery remaining amount indications (3) in the first and second embodiments are In the third embodiment, the warning lamp is turned on.

  In order to realize such a function, the portable device 2 executes a process as shown in FIG. The process described below is also executed when an RF transmission request is generated in the portable device 2.

  When the RF transmission request is generated, the portable device 2 first starts RF transmission (S505). At this point, transmission of a preamble or the like is started and data transmission is not performed, as in the first embodiment. Then, the portable device 2 determines whether or not the battery voltage V is greater than the predetermined voltage V2 (S510). If it is greater (S510: YES), the battery voltage drop flag is set to “0” ( S515), data transmission is started (S520). Then, until the data transmission is completed, the end of the data transmission is waited (S525: NO). When the data transmission is completed (S525: YES), the processing shown in FIG. 7 is terminated.

  When the battery voltage V is equal to or lower than the predetermined voltage V2 (S510: NO), the portable device 2 sets “1” in the battery voltage drop flag (S530), and switches the transmission power to low power ( S535). Thereby, the transmission power of the portable device 2 becomes lower than before the switching, and the current taken out from the battery unit 24 is switched from the current I1 shown in FIG. 6A to the current I2.

  The portable device 2 starts data transmission after switching the transmission power (S540). Then, if the battery voltage V exceeds the predetermined voltage V3 (S545: YES), the end of data transmission is waited (S550: NO).

  Then, when the data transmission is completed in the repetition of S545 to S550 (S550: YES), the processing shown in FIG. 7 is terminated. On the other hand, when the battery voltage V becomes equal to or lower than the predetermined voltage V3 during the repetition of S545 to S550 (S545: NO), the processing shown in FIG. 7 is ended without waiting for the end of data transmission.

  Now, when the process as described above is executed in the portable device 2, the process as shown in FIG. 8 is executed in the in-vehicle device 1. This process is a process that is executed when a radio signal from the portable device 2 is received by the RF reception process that is always executed in the in-vehicle device 1.

  When this process is started, the in-vehicle device 1 first verifies whether data has been normally received from the portable device 2 (S605). Then, if the battery is successfully received (S605: YES), it is determined whether or not the battery voltage drop flag included in the data string is “1” (S610). If it is “1” (S610: YES) ) The warning lamp on the display unit 14 is turned on to display a battery voltage drop warning (S615). Then, the function corresponding to the received data is performed (S620), and the process shown in FIG.

  On the other hand, if the battery voltage drop flag included in the received data string is not “1” (S610: NO), the process step of S615 is skipped and the process proceeds to the process step of S620. The corresponding function is executed (S620), and the process shown in FIG.

By executing the processing as described above by each of the in-vehicle device 1 and the portable device 2, it is possible to realize notification of the remaining battery level by turning on / off the warning light as described above.
In addition, when the remaining battery level is low by the processing step of S535, the battery power can be extended and the lighting period of the warning lamp can be extended by switching the transmission power of the portable device 2 to low power.

Therefore, compared with the case where the transmission power is not controlled, the possibility that the user notices the necessity of battery replacement can be increased, and the user can prevent the portable device 2 from being in a non-functional state. Can be prevented.
(4) Fourth Embodiment Next, a fourth embodiment will be described. In the fourth embodiment, as in the third embodiment, the warning lamp is turned on / off to notify the user. However, as in the second embodiment, the battery voltage drop flag is stored in the storage unit 27. In this configuration, transmission power can be reduced before RF transmission starts.

  In the fourth embodiment, the processing content in the in-vehicle device 1 is exactly the same as that in the third embodiment, but the processing content in the portable device 2 is different from that in the third embodiment. The processing executed by will be described with reference to FIG.

  When the RF transmission request is generated, the portable device 2 first reads the battery voltage drop flag from the storage unit 27 (S705). Here, the battery voltage drop flag stored in the storage unit 27 when the portable device 2 is operated last time is read out.

  Then, it is determined whether or not the battery voltage drop flag is “0” (S710). If it is “0” (S710: YES), RF transmission is started (S715), and then data transmission is started (S720). ).

  Subsequently, the portable device 2 waits for the end of data transmission until the data transmission is completed (S725: NO). When the data transmission is completed (S725: YES), is the battery voltage V greater than the predetermined voltage V2 at this stage? It is determined whether or not (S730).

  If the battery voltage V is greater than the predetermined voltage V2 (S730: YES), “0” is set in the battery voltage drop flag, and the information is written in the storage unit 27 (S735), as shown in FIG. The processing shown in FIG.

  On the other hand, when the battery voltage V is equal to or lower than the predetermined voltage V2 (S730: NO), the portable device 2 sets “1” in the battery voltage drop flag and writes the information in the storage unit 27 (S740). Then, the process shown in FIG.

  On the other hand, if the battery voltage drop flag is not “0” in S710 (S710: NO), the portable device 2 switches the transmission power to low power (S745). Thereby, the transmission power of the portable device 2 becomes lower than before the switching, and the current taken out from the battery unit 24 is switched from the current I1 shown in FIG. 6A to the current I2.

  After switching the transmission power, the portable device 2 starts RF transmission (S750), and then starts data transmission (S755). If the battery voltage V exceeds the predetermined voltage V3 (S760: YES), the process waits for the end of data transmission (S765: NO).

  If the data transmission is completed in the repetition of S760 to S765 (S765: YES), the process proceeds to S730. Thereafter, as already described, the processes of S730 to S740 are executed.

  If the battery voltage V becomes equal to or lower than the predetermined voltage V3 during the repetition of S760 to S765 (S795: NO), the process shown in FIG. 9 is performed without waiting for the end of data transmission. finish.

  The portable device 2 executes the processing as described above, and the vehicle-mounted device 1 executes the same processing as that of the third embodiment, so that the battery by turning on / off the warning lamp as described in the third embodiment Notification of the remaining amount can be realized.

  In addition, when the remaining battery level is low by the processing step of S745, it is possible to extend the battery life and extend the lighting period of the warning lamp by switching the transmission power of the portable device 2 to low power.

  Therefore, compared with the case where the transmission power is not controlled, the possibility that the user notices the necessity of battery replacement can be increased, and the user can prevent the portable device 2 from being in a non-functional state. Can be prevented.

Also, in the fourth embodiment, the battery voltage drop flag is seen in the processing step of S710, the transmission power is reduced in S745, and then RF transmission is started in S750, which is different from the third embodiment. The battery voltage V does not fall below the voltage V3 before the transmission power is reduced due to the start of RF transmission. Therefore, the chance that the portable device 2 can function normally can be increased more than the system of the third embodiment.
(5) Other Embodiments Although the embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment described above, and can be implemented in various other forms.

  For example, in the above embodiment, a system having both a so-called remote keyless entry function and a smart entry function has been described as an example. However, the configuration of the present invention is also adopted in a system having either one of these functions. Can do.

  In this case, if the system has only the remote keyless entry function, the vehicle-mounted device existing in the first to fourth embodiments, such as the vehicle-mounted device 31 and the portable device 32 shown in FIG. The configuration necessary for the LF communication may be omitted.

Moreover, in the said embodiment, although the some control object by the vehicle equipment was illustrated concretely, the control object by an vehicle equipment is not necessarily limited only to what was mentioned concretely.
Furthermore, in the said embodiment, although the example which performs the visual alerting | reporting by a display was shown, you may perform the auditory alerting | reporting by a sound.

  Moreover, in the said embodiment, the example which performs 3 steps | paragraphs of notifications and 2 steps | paragraphs of transmission output switching (1st, 2nd embodiment) The example which performs 2 steps | paragraphs of notifications and 2 steps | paragraphs of transmission output switching (3rd, 3rd) 4 embodiment), the notification and transmission output may be switched in any number of stages.

  For example, by reducing the transmission output every time the battery voltage drops to some extent, the communication area can be narrowed down more finely and in steps, so the communication area suddenly narrows as the transmission output is switched Can be suppressed.

The block diagram which shows schematic structure of the remote control system for vehicles. (A) is the graph which shows the characteristic of the battery part in 1st, 2nd embodiment, (b) is those about battery voltage in 1st, 2nd embodiment, operation | movement of a portable device, and the display in vehicle equipment. Explanatory drawing for demonstrating a relationship, (c) is explanatory drawing which shows the specific design of the battery remaining charge display in 1st, 2nd embodiment. The flowchart of the process which the portable device of 1st Embodiment performs. The flowchart of the process which the vehicle equipment of 1st Embodiment performs. The flowchart of the process which the portable device of 2nd Embodiment performs. (A) is a graph showing the characteristics of the battery unit in the third and fourth embodiments, (b) is the battery voltage, the operation of the portable device, and the display on the in-vehicle device in the third and fourth embodiments. Explanatory drawing for demonstrating a relationship. The flowchart of the process which the portable device of 3rd Embodiment performs. The flowchart of the process which the vehicle equipment of 3rd Embodiment performs. The flowchart of the process which the portable device of 4th Embodiment performs. The block diagram which shows schematic structure of the remote control system for vehicles at the time of setting it as the one-way communication from a portable device to vehicle equipment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,31 ... Vehicle equipment, 2,32 ... Portable machine, 11,21 ... Control part, 12, 23 ... Transmission part, 13, 22 ... Reception part, 14 ... Display Unit, 24 ... battery unit, 25 ... battery voltage level detection unit, 26 ... transmission power switching unit, 27 ... storage unit, 28, 29 ... push switch.

Claims (3)

A vehicle-mounted device mounted on a vehicle and a portable device carried by a user. The vehicle-mounted device performs predetermined control when a predetermined wireless signal is transmitted from the portable device to the vehicle-mounted device. A vehicle remote control system configured to perform:
The portable device is
Detecting means for detecting a remaining battery level in the portable device;
When the remaining amount level detected by the detection unit is lower than a predetermined switching reference, the transmission output switching unit that switches the transmission output of the radio signal to a lower output;
A transmission means for transmitting a wireless signal including data indicating the remaining amount level detected by the detection means to the in-vehicle device;
With
The in-vehicle device is
Receiving means for receiving a radio signal transmitted from the portable device;
Informing means for informing a user of information related to the remaining amount level based on data indicating the remaining amount level included in the wireless signal received by the receiving means ,
In the portable device,
When the transmission output switching means switches the transmission output of the radio signal to a lower output, the transmission means indicates that the transmission output is switched as data indicating the remaining amount level on the in-vehicle device side. A wireless signal including discriminable data is transmitted to the in-vehicle device,
In the in-vehicle device,
Based on the data indicating the remaining amount level, the notifying unit switches the plurality of notification modes step by step until the remaining amount level is lower than the switching reference, so that the remaining state is reduced. When the remaining amount level is lower than the switching reference, the user is notified that the transmission output has been switched by further switching the notification mode.
A remote control system for a vehicle. In the portable device, the transmission output switching means stores the information when the transmission output is switched at the time of operation, and before starting transmission of the radio signal at the next operation, the transmission output is switched. The vehicle remote control system according to claim 1 , wherein the output is switched to the same output as when the information is stored. The portable device is
When the remaining amount level detected by said detecting means is lower than a predetermined stopping criterion, according to claim 1 or claim 2, characterized in that it comprises a transmission stop control means for stopping the transmission of the radio signal Remote control system for vehicles.

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