JP2007186065A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless vehicle control device capable of suppressing increase of a dark current. <P>SOLUTION: The wireless vehicle control device 100 is provided with CPU 20, a logic IC 30; and a receiver 40. The receiver 40 (tuner 50) receives an electric wave transmitted from the outside and outputs a signal corresponding to the electric wave. The CPU 20 receives a wake-up signal, is activated and controls an on-vehicle equipment based on the signal corresponding to at least the electric wave during activation. Then, in the logic IC 30, a consumption current is smaller than the CPU 20 and the logic IC 30 outputs a wake-up signal for activating the CPU 20 based on a signal (RSSI, RDA) corresponding to the electric wave outputted from the receiver 40 (tuner 50). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless vehicle control apparatus that controls in-vehicle devices wirelessly.

  Conventionally, there has been one disclosed in Patent Document 1 as a wireless vehicle control device that reduces current consumption.

  The wireless vehicle control device disclosed in Patent Document 1 includes a reception device, a control device, and the like that are provided at positions separated from each other in the vehicle. The reception device includes a reception circuit, a demodulation circuit, a power supply control circuit, and the like. The control device includes a CPU, a drive circuit, a power supply circuit, and the like.

  The CPU outputs a signal for instructing the start of power supply to the power supply control circuit, then identifies the control signal input from the demodulation circuit, outputs a drive signal corresponding to the identification result to the drive circuit, and then stops power supply. A signal to be commanded is output to the power supply control circuit, and the CPU wakes up every predetermined time and returns to the sleep mode when the above processing is completed.

As described above, the wireless vehicle control device disclosed in Patent Document 1 intermittently drives the CPU in the control device, and the CPU in the control device issues a power supply start command, a power supply stop command, and the like to the power control circuit of the reception device. As a result, it is not necessary to provide a CPU in the receiving apparatus, and current consumption can be reduced.
JP-A-8-332841

  However, with the recent increase in functionality of vehicles, it is necessary to increase the processing speed by the CPU. As the processing speed of the CPU increases, the current consumption of the CPU itself increases. Therefore, even when the CPU is woken up every predetermined time (for example, several hundred ms) as in the wireless vehicle control device disclosed in Patent Document 1, it is possible to suppress the dark current of the wireless vehicle control device. It was difficult.

  The present invention has been made in view of the above problems, and an object thereof is to provide a wireless vehicle control device capable of suppressing an increase in dark current.

  In order to achieve the above object, a wireless vehicle control device according to claim 1 is activated by receiving a wake-up signal and a receiving device that receives a radio wave transmitted from the outside and outputs a signal corresponding to the radio wave. A CPU that controls the in-vehicle device based on at least a signal corresponding to radio waves during startup, and a wake-up signal that consumes less current than the CPU and activates the CPU based on signals corresponding to radio waves output from the receiving device And a wake-up circuit that outputs.

  As described above, the CPU is activated in response to the wake-up signal, consumes less current than the CPU, and outputs the wake-up signal to activate the CPU based on the signal corresponding to the radio wave output from the receiving device. As a result, an increase in dark current can be suppressed as compared with the case where the CPU is operated intermittently.

  In the wireless vehicle control device according to claim 2, the wake-up circuit repeats a wake-up state and a standby state every predetermined time.

  As described above, it is possible to further suppress an increase in dark current by repeating the wake-up state and the standby state every predetermined time with respect to the wake-up circuit.

  In the wireless vehicle control device according to claim 3, the receiving device outputs a radio signal indicating the electric field strength of the radio wave and a control signal obtained by demodulating the radio wave as a signal corresponding to the radio wave. Is characterized in that a wakeup signal is output when the radio signal indicates a predetermined electric field strength and the control signal satisfies a predetermined condition.

  As described above, when the radio signal indicates a predetermined electric field strength and the control signal satisfies a predetermined condition, the CPU is surely activated only when necessary by outputting the wake-up signal. it can.

  The predetermined condition may be a case where the edge of the control signal is detected a predetermined number of times.

  In the wireless vehicle control device according to claim 5, the receiving device outputs a radio signal indicating the electric field strength of the radio wave and a control signal obtained by demodulating the radio wave as a signal corresponding to the radio wave. Is characterized in that a wake-up signal is output when the radio signal shows a predetermined electric field strength.

  Thus, even if the wake-up signal is output when the radio wave signal indicates a predetermined electric field strength, the CPU can be activated only when necessary.

  Moreover, as shown in claim 6 or claim 7, the CPU can control the state of the vehicle door or the start of the vehicle engine as the control of the in-vehicle device.

  The wireless vehicle control device according to claim 8 includes a transmission device that transmits radio waves, and the CPU superimposes a request signal for requesting transmission of radio waves transmitted from the outside on the radio waves and transmits from the transmission device. It can also be done.

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

  FIG. 1 is a block diagram showing a schematic configuration of a wireless vehicle control device according to an embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of the logic IC in the embodiment of the present invention. FIG. 3 is a flowchart for explaining the operation of the logic IC in the embodiment of the present invention. FIG. 4 is a flowchart illustrating wireless reception determination of the wireless vehicle control device according to the embodiment of the present invention. FIG. 5 is a time chart for explaining the operation of the wireless vehicle control device according to the embodiment of the present invention.

  The wireless vehicle control device 100 according to the present embodiment controls the lock / unlock state of each door based on the ID code collation result by bidirectional communication with the portable device (electronic key) 60, and The present invention is suitably applied to a wireless vehicle control apparatus that performs control of opening and closing, control of a steering lock state in order to improve vehicle security, and control of permission / prohibition state of vehicle engine start.

  As shown in FIG. 1, the wireless vehicle control device 100 includes a control ECU 10, a receiver (reception device) 40, and the like.

  As shown in FIG. 2, the control ECU 10 includes a CPU 20, a logic IC 30, and the like. The CPU 20 superimposes a request signal (LF radio signal) requesting the portable device 60 to transmit radio waves on the radio waves and transmits the request signal from a transmission device (not shown). Then, the CPU 20 controls the locking / unlocking state of each door and the opening / closing control of each door based on a signal corresponding to the radio wave transmitted from the portable device 60 and received by the receiver 40 in response to the request signal. An arithmetic processing unit that performs arithmetic processing for implementing control of the steering lock state and further control of permission / prohibition of the engine start of the vehicle in order to improve the security of the vehicle. As shown in FIG. 5, the CPU 20 is activated when a wakeup signal is output from the logic IC 30 and maintains a sleep state until the wakeup signal is output.

  The logic IC 30 corresponds to the wake-up circuit in the present invention, and is a logic circuit that is driven with a current consumption smaller than that of the CPU 20. The logic IC 30 includes a wireless reception determination circuit 31, an ACK reception determination circuit 32, an LF oscillation circuit 33, a tuner control circuit 34, a serial communication circuit 35, and the like. Further, the logic IC 30 is intermittently driven as shown in FIG. 5 and is activated by this wireless reception determination start trigger to be in an activated state (wake-up state), waits for a wireless reception determination start trigger after executing predetermined processing. It will be in the standby state which is the state of.

  The wireless reception determination circuit 31 determines whether or not a regular radio wave is received based on signals (RDA, RSSI) corresponding to the received radio wave output from the tuner 50 (hereinafter referred to as wireless reception determination). And a circuit for determining whether or not to start the CPU 20. If the wireless reception determination circuit 31 determines that a normal radio wave is received in the wireless reception determination, the wireless reception determination circuit 31 sets a determination OK flag, that is, outputs a wakeup signal to the CPU 20. Note that RDA, which is a signal corresponding to radio waves, is a control signal in the present invention, and RSSI is a radio signal indicating the electric field strength of radio waves in the present invention. When the tuner 50 receives a radio wave, the tuner 50 includes a demodulation circuit that demodulates the radio wave and an RSSI detection circuit that detects the electric field strength of the radio wave.

  The ACK reception determination circuit 32 is a circuit that determines whether or not an ACK has been received based on a signal (RDA, RSSI) corresponding to the received radio wave output from the tuner 50. The LF transmission circuit 33 receives the wireless reception determination start trigger output from the trigger output circuit 36 and supplies a low frequency clock to the wireless reception determination circuit 31 and the ACK reception determination circuit 32.

  The tuner control circuit 34 drives and controls the tuner 50 by receiving a wireless reception determination start trigger output from the trigger output circuit 36 and supplying power from a battery (not shown) to the tuner 50. The serial communication circuit 35 is a circuit that performs serial communication with the CPU 20. When receiving a signal indicating that the CPU 20 has started up, the serial communication circuit 35 outputs a clear signal that clears the determination OK flag to the wireless reception determination circuit 31 and the ACK reception determination circuit 32. Output. The trigger output circuit 36 is an IC chip that outputs a wireless reception determination start trigger indicating the start of wireless reception determination to the logic IC 30 every predetermined time (for example, every 250 ms).

  Next, the processing operation of the logic IC 30 will be described. The flowchart shown in FIG. 3 starts when power is supplied from a battery (not shown) to enter a standby state.

  First, in step S10, the wireless reception determination circuit 31 and the tuner control circuit 34 in the logic IC 30 determine whether or not a wireless reception determination start trigger is input from the trigger output circuit 36, and the wireless reception determination start trigger is input. When it determines, it progresses to step S20, and when it determines with the wireless reception determination start trigger not being input, the determination in step S10 is repeated.

  In step S20, the tuner control circuit 34 in the logic IC 30 supplies power from a battery (not shown) to the tuner 50 in order to perform a process for determining whether or not a regular radio wave is received, that is, a wireless reception determination process. For example, the tuner 50 is driven and controlled. Then, the wireless reception determination circuit 31 in the logic IC 30 determines whether or not to activate the CPU 20 based on a signal (RDA, RSSI) corresponding to the received radio wave output from the tuner 50. Process. The wireless reception determination process will be described in detail later.

  In step S30, it is determined whether or not the result of the wireless reception determination in step S20 is OK. If it is determined that it is OK, the process proceeds to step S40, and if it is determined that it is not OK (NG), step S30 is performed. Return to S10.

  In step S <b> 40, the wireless reception determination circuit 31 in the logic IC 30 receives the regular radio wave at the tuner 50, and therefore outputs a wakeup signal to the CPU 20 to activate the CPU 20. As shown at point C in FIG. 5, when this wake-up signal is input, the CPU 20 starts from the sleep state and executes predetermined processing.

  In step S50, the wireless reception determination circuit 31 in the logic IC 30 determines whether or not a clear signal for clearing the determination OK flag has been received from the serial communication circuit 35. If it is determined that the clear signal has been received, the determination OK flag is determined. Is cleared to end the process, and if it is determined that the clear signal has not been received, the process returns to step S40.

  Next, the wireless reception determination process will be described with reference to FIG. The flowchart shown in FIG. 4 starts when a wireless reception determination start trigger is input.

  First, in step S110, as indicated by a point A in FIG. 5, the wireless reception determination circuit 31 passes after a predetermined time elapses from the standby state to the start-up state (wake-up state) until the power source of the tuner 50 is stabilized ( For example, after 10 ms), it is determined whether RSSI is input from the tuner 50. If it is determined that RSSI indicating the predetermined electric field strength is input, the process proceeds to step S120, and RSSI indicating the predetermined electric field strength is input. If it is determined that it is not, the process proceeds to step S260.

  Then, as indicated by point B in FIG. 5, the wireless reception determination circuit 31 reads the RDA after a predetermined time has elapsed (for example, after 5 ms) in step S120 in order to analyze the RDA, and in step S130, the predetermined value is determined. It is determined whether or not there is an edge during a time (for example, 2800 μs). If it is determined that there is an edge, the process proceeds to step S140. If it is determined that there is no edge, the process proceeds to step S260. In step S260, the wireless reception determination circuit 31 determines that the read signal is not RD but noise and is NG.

  In step S140, the wireless reception determination circuit 31 reads a port to which RDA is input and stores the value as data 0. In steps S150 and S160, the wireless reception determination circuit 31 counts edges while a predetermined time (933 μm) elapses. If the wireless reception determination circuit 31 determines that a predetermined time has elapsed, the wireless reception determination circuit 31 proceeds to step S170.

  In step S170, the wireless reception determination circuit 31 determines whether or not the edge counted in step S150 is a predetermined number of times (for example, four times) or more. If it is determined that the edge is not the predetermined number or more, the process proceeds to step S190. If it is determined that the number is equal to or greater than the predetermined number, the process proceeds to step S260. This determination process is for allowing noise in the RDA signal, and in the case where noise is not allowed, this determination process can be omitted.

  In step S180, the wireless reception determination circuit 31 reads a port to which RDA is input and stores the value as data 1.

  In step S190, the wireless reception determination circuit 31 determines whether or not there is an edge during a predetermined time (for example, 933 μs). If it is determined that there is an edge, the process proceeds to step S200. If it is determined that there is no edge, the process proceeds to step S210.

  In step S200, the wireless reception determination circuit 31 reads a port to which RDA is input and stores the value as data 0.

  On the other hand, if it is determined in step S190 that there is no edge, in step S210, the wireless reception determination circuit 31 reads a port to which RDA is input and stores the value as data 2.

  In step S220, the wireless reception determination circuit 31 determines whether the data determination is OK. That is, if the values of data 0, data 1, and data 2 read in steps S140, S180, and S210 do not change (in the case of 000 or 111), the wireless reception determination circuit 31 determines that the data determination is not OK (NG). Determine and proceed to step S260. On the other hand, if the values of data 0, data 1, and data 2 read in steps S140, S180, and S210 have changed, the wireless reception determination circuit 31 determines that the data determination is OK and proceeds to step S230 to count up. To do.

  In step S240, the wireless reception determination circuit 31 determines whether or not the count value is a predetermined number. If it is determined that the count value is not the predetermined number, the process returns to step S160. On the other hand, if the count value is the predetermined number of times, the wireless reception determination circuit 31 proceeds to step S250 and determines that the normal RDA is input and determines that it is OK. That is, the wireless reception determination circuit 31 outputs a wake-up signal to activate the CPU 20 when an RDA edge is detected a predetermined number of times.

  In this way, the logic IC 30 that consumes less current than the CPU 20 outputs the wake-up signal based on the signals (RSSI, RDA) corresponding to the radio wave output from the receiver 40 (tuner 50) to By starting, an increase in dark current can be suppressed as compared with the case where the CPU 20 is operated intermittently.

  The CPU 20 controls the lock / unlock state of each door, controls the opening / closing of each door, controls the steering lock state in order to improve the security of the vehicle, and controls the permission / prohibition state of the vehicle engine start. Is an arithmetic processing unit that performs arithmetic processing for performing the above and the like, and has the largest current consumption among the electronic components mounted on the control ECU 10. Therefore, the dark current of the control ECU 10 can also be suppressed by suppressing the dark current by the CPU 20.

  The wireless reception determination circuit 31 has a RSSI indicating a predetermined electric field strength. Since the wake-up signal is output when the RDA edge is detected a predetermined number of times, the CPU can be activated only when necessary.

  Further, regarding the logic IC 30 as well, an increase in dark current can be further suppressed by repeating the wake-up state and the standby state every predetermined time.

  In this embodiment, the trigger output circuit 36 is provided and the wireless reception determination start trigger is output to the logic IC 30 every predetermined time. However, the present invention is not limited to this. .

  For example, the CPU 20 includes a main oscillation circuit that generates a main clock for operating the CPU 20 and a sub oscillation circuit that generates a sub clock having a frequency lower than that of the main clock. Further, the CPU 20 may be provided with a trigger output circuit that is operated by the sub oscillation circuit when the main oscillation circuit stops operating (sleep state). Further, the logic IC 30 itself may be provided with a timer, and may be activated every predetermined time by the logic IC 30 itself to perform wireless reception determination.

  Also, in the present embodiment, the wireless reception determination circuit 31 determines whether or not to output a wakeup signal based on signals (RSSI, RDA) corresponding to radio waves output from the receiver 40 (tuner 50). However, the present invention is not limited to this. The wireless reception determination circuit 31 may output a wakeup signal when the RSSI indicates a predetermined electric field strength. As described above, even when the wakeup signal is output when the RSSI indicates a predetermined electric field strength, the CPU can be activated only when necessary.

  In the present embodiment, the logic IC 30 that is driven with a current consumption smaller than that of the CPU 20 is described as the wake-up circuit, but the present invention is not limited to this. Any device may be used as long as it can be driven with a current consumption smaller than that of the CPU 20 and can execute a wireless reception determination process or the like.

It is a block diagram which shows schematic structure of the wireless vehicle control apparatus in embodiment of this invention. It is a block diagram which shows schematic structure of the logic IC in embodiment of this invention. It is a flowchart explaining operation | movement of the logic IC in embodiment of this invention. It is a flowchart explaining the wireless reception determination of the wireless vehicle control apparatus in embodiment of this invention. It is a time chart explaining operation | movement of the wireless vehicle control apparatus in embodiment of this invention.

Explanation of symbols

10 control ECU, 20 CPU, 30 logic IC, 31 wireless reception determination circuit, 32 ACK reception determination circuit, 33 LF oscillation circuit, 34 tuner control circuit, 35 serial communication circuit, 36 trigger output circuit, 40 receiver, 50 tuner, 60 Mobile devices

Claims (8)

A receiving device that receives a radio wave transmitted from the outside and outputs a signal corresponding to the radio wave;
A CPU that starts upon receiving a wake-up signal, and controls the in-vehicle device based on at least a signal corresponding to the radio wave during startup;
A wake-up circuit that outputs a wake-up signal that activates the CPU based on a signal corresponding to the radio wave output from the receiving device, the current consumption being smaller than the CPU;
A wireless vehicle control device comprising:   The wireless vehicle control device according to claim 1, wherein the wake-up circuit repeats a wake-up state and a standby state every predetermined time.   The receiving device outputs a radio signal indicating the electric field strength of the radio wave as a signal corresponding to the radio wave and a control signal obtained by demodulating the radio wave, and the wake-up circuit has the predetermined electric field strength. The wireless vehicle control device according to claim 1, wherein the wakeup signal is output when the control signal satisfies a predetermined condition.   The wireless vehicle control device according to claim 3, wherein the wake-up circuit outputs the wake-up signal when the edge of the control signal is detected a predetermined number of times as the predetermined condition.   The receiving device outputs a radio signal indicating the electric field strength of the radio wave as a signal corresponding to the radio wave and a control signal obtained by demodulating the radio wave, and the wake-up circuit has the predetermined electric field strength. The wireless vehicle control device according to claim 1, wherein the wake-up signal is output when the wake-up signal is displayed.   The wireless vehicle control device according to claim 1, wherein the CPU includes control of a state of a vehicle door as control of the in-vehicle device.   The wireless vehicle control device according to claim 1, wherein the CPU includes a start control of a vehicle engine as a control of the in-vehicle device.   2. The transmission device according to claim 1, further comprising: a transmission device configured to transmit a radio wave, wherein the CPU transmits a request signal requesting transmission of the radio wave transmitted from the outside, superimposed on the radio wave from the transmission device. The wireless vehicle control device according to claim 7.

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