JP2007332705A - Wireless key system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recognize a key position outside an automobile at low cost and high accuracy. <P>SOLUTION: When the strength of a radio signal from a radio communication part 6 becomes equal to or greater than a threshold value, a main control part 10 performs control so that sensor parts from a front right sensor part 11 to a rear left sensor part 18 output millimeter wave signals in turn. When a sensor receiving part 7 receives the millimeter wave signal of certain sensor parts, a response signal indicating that the received millimeter wave signal from the sensor part has been received is output. On the basis of the response signal, the main control part 10 specifies the sensor part that output the millimeter wave signal received by a key side radio communication part 2. A millimeter wave signal is output again from the specified sensor part and the position and size of a surrounding object (key carrier) are measured from the reflected wave of the signal so as to detect the detailed position of the key (key carrier). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a key system position recognition technique by wireless communication, and more particularly to an effective technique for accurately recognizing a key position outside a car in a key system used in a car.

  As a keyless entry system for an automobile, for example, a system that locks and unlocks a door and starts and stops an engine by simply carrying a card-like key is widely known.

  This keyless entry system is generally unlocked when an ID (IDentity) is recognized by a signal transmitted from the automobile side and a response signal is returned in response to the key.

  However, the present inventors have found that the key recognition technology using the keyless entry system as described above has the following problems.

  In recent years, research on ITS (Intelligent Transport System) that network people, roads, and vehicles with information using the most advanced information communication technology has been actively conducted, and advanced security such as ITS, unlocking, and locking. High-accuracy position recognition technology for key users such as control technology may become indispensable.

  However, in the keyless entry system described above, since the key is recognized depending on whether or not it responds to a signal transmitted from the automobile side, it is only recognized that the key carrier has approached the automobile. There is a problem that the position of the key in the car cannot be recognized with high accuracy.

  Further, according to the inventor's study, as a technique for accurately recognizing the position of the key in the automobile, for example, the automobile is provided with a plurality of wireless antennas, and the keys received by the plurality of wireless antennas are used. However, in this system, a large dedicated radio communication system is required, and the cost is very high.

  An object of the present invention is to provide a technique capable of recognizing a key position outside a vehicle with low cost and high accuracy.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  A wireless key system according to the present invention includes a key-side wireless communication unit that is provided in a key and outputs a wireless signal for recognizing the key, and an automobile-side wireless communication unit provided in the automobile, the automobile-side wireless communication unit Receives a radio signal from the key-side wireless communication unit, and detects a key approaching the vehicle to an arbitrary distance and a key detection unit provided at an arbitrary position of the vehicle, and transmits and receives a position detection signal A plurality of position detection sensor units and a key position calculation unit that calculates the detailed position of the key using the position detection signal of the position detection sensor unit when the key detection unit detects the key. Is.

  Moreover, the outline | summary of the other invention of this application is shown briefly.

  In the wireless key system of the present invention, when the position detection sensor unit detects a key, the position detection sensor unit transmits an identification signal individually given to each position detection sensor unit, and the key side wireless When the communication unit receives the identification signal from the position detection sensor unit, the communication unit outputs a response signal indicating that the identification signal from which position detection sensor unit has been received based on the received identification signal. The key position calculation unit recognizes in which region of the vehicle the key is located from the response signal of the key side wireless communication unit.

  The wireless key system according to the present invention corresponds to the recognized position among the plurality of position detecting sensor units when the key position calculating unit recognizes in which region of the vehicle the key is located. A position detection signal is transmitted from the position detection sensor unit, and the position and size of objects around the automobile are calculated from the reflected waves received by the position detection sensor unit, and the detailed position of the key is detected. is there.

  Furthermore, in the wireless key system of the present invention, the position detection signal output from the position detection sensor unit is a millimeter wave signal.

  In the wireless key system of the present invention, the identification signal output from the position detection sensor unit is a millimeter wave signal.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  (1) The position of the key (key carrier) can be detected with high accuracy.

  (2) Further, according to the above (1), it is possible to realize an advanced security control technology for automobiles.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 is a block diagram showing an example of a wireless key system according to an embodiment of the present invention. FIG. 2 shows an example of a wireless communication area and a millimeter wave signal area covered by the wireless key system of FIG. FIG. 3 and FIG. 3 are flowcharts showing an operation example in the wireless key system of FIG.

  In the present embodiment, the wireless key system 1 recognizes the position of the key (the carrier) outside the automobile with high accuracy, and also performs advanced security control such as door locking and unlocking, and engine starting and stopping. It is a system that performs.

  As shown in FIG. 1, the wireless key system 1 includes a key-side wireless communication unit 2 and an automobile-side wireless communication unit 3. The key-side wireless communication unit 2 is a system provided in a car key. The key-side wireless communication unit 2 includes antennas 4 and 5, a wireless communication unit 6, a sensor reception unit 7, and a key-side control unit 8. It is configured.

  The vehicle-side wireless communication unit 3 is a system provided on the vehicle side, and includes a wireless communication unit (key detection unit) 9, a main control unit (key detection unit, key position calculation unit) 10, a front right detection sensor unit. (Position detection sensor) 11, front left detection sensor section (position detection sensor) 12, right front detection sensor section (position detection sensor) 13, right rear detection sensor section (position detection sensor) 14, left A forward detection sensor (position detection sensor) 15, a left rear detection sensor (position detection sensor) 16, a rear right detection sensor (position detection sensor) 17, and a rear left detection sensor (position detection) Sensor) 18.

  These sensor units 11 to 18 are used in combination with the sensors of the safety support system when a sensor of a millimeter wave radar used for a safety support system that assists in preventing the collision of the automobile or reducing the collision damage is provided. The configuration.

  The antenna 4 transmits and receives a radio signal from the vehicle-side radio communication unit 3. The antenna 5 receives, for example, a millimeter wave signal output from the automobile-side wireless communication unit 3. The wireless communication unit 6 performs wireless communication with the key-side wireless communication unit 2.

  The sensor receiver 7 detects a millimeter wave signal received via the antenna 5. The key-side control unit 8 manages all control in the key-side wireless communication unit 2.

  The radio communication unit 9 is provided with an antenna 9a, and transmits and receives radio signals from the key-side radio communication unit 2 input via the antenna 9a. The main control unit 10 manages all the controls in the vehicle-side wireless communication unit 3.

  These front right detection sensor unit 11, front left detection sensor unit 12, right front detection sensor unit 13, right rear detection sensor unit 14, left front detection sensor unit 15, left rear detection sensor unit 16, rear The right detection sensor unit 17 and the rear left detection sensor unit 18 include antennas 11a to 18a, sensors 11b to 18b, and sensor control units 11c to 18c, respectively.

  The front right detection sensor unit 11 is provided on the right side of the front part of the automobile, and the front left detection sensor part 12 is provided on the left side of the front part of the automobile. The right front detection sensor unit 13 is provided in the front part on the right side of the automobile, and the right rear detection sensor part 14 is provided in the rear part on the right side of the automobile.

  The left front detection sensor unit 15 is provided in the front part of the left side of the automobile, and the left rear detection sensor part 16 is provided in the rear part of the left side of the automobile. The rear right detection sensor part 17 is provided on the right side of the rear part of the automobile, and the rear left detection sensor part 18 is provided on the left side of the rear part of the automobile.

  The sensors 11b to 18b are made of, for example, a millimeter wave radar. These sensors 11b to 18b transmit millimeter wave signals as position detection signals via the antennas 11a to 18a according to the control of the individual sensor control units 11c to 18c, and the reflected waves are transmitted to the antennas 11a to 18a. Receive via. Based on the control of the main control unit 10, the sensor control units 11c to 18c control transmission and reception of millimeter wave signals by the sensors 11b to 18b, respectively.

  FIG. 2 shows a wireless communication region MR, a front right detection sensor unit 11 and a front left detection sensor that are covered by the wireless communication unit 6 of the key side wireless communication unit 2 and the wireless communication unit 9 of the automobile side wireless communication unit 3. Section 12, right front detection sensor section 13, right rear detection sensor section 14, left front detection sensor section 15, left rear detection sensor section 16, rear right detection sensor section 17, and rear left detection sensor section. 18 is an explanatory diagram showing millimeter wave signal regions RR1 to RR8 that are covered by 18 respectively.

  In FIG. 2, the wireless communication areas MR covered by the wireless communication of the wireless communication sections 6 and 9 are indicated by ◯ marks, and the millimeter wave signal areas RR1 to RR8 covered by the respective detection sensor sections 11 to 18 are Each is shown by shading.

  When a key enters the wireless communication area MR, it is determined that the passenger has approached the vehicle by wireless communication between the key-side wireless communication unit 2 and the vehicle-side wireless communication unit 3.

  Subsequently, after determining which region of the millimeter wave signal regions RR1 to RR8 the key is located using the detection sensor units 11 to 18, accurate key position detection is performed.

  Next, the operation of the wireless key system 1 in the present embodiment will be described using the flowchart of FIG. Here, an operation example when the location of the key (key carrier) is in the millimeter wave signal region RR1 will be described.

  First, in the key-side radio communication unit 2 shown on the right side of FIG. 3, the radio communication unit 6 outputs a radio signal at regular intervals (step S101) and receives a radio signal from the car-side radio communication unit 3 (step S101). The operation of S102) is performed.

  In the car-side radio communication unit 3 shown on the left side of FIG. 3, the radio communication unit 9 performs a radio signal reception operation (step S103) and the main control unit 10 performs a key detection operation (step S104). Yes.

  In this case, the wireless communication unit 9 performs a reception operation of the wireless signal output from the wireless communication unit 6 at regular intervals, and determines whether the received signal strength is equal to or higher than an arbitrary threshold value. Determine the strength of the. When the strength of the received signal becomes equal to or greater than the threshold value, main controller 10 determines that the key has entered wireless communication region MR in FIG.

  In the process of step S104, when the strength of the received signal becomes equal to or greater than the threshold value, the wireless communication unit 9 transmits a new response signal to the wireless communication unit 6 (step S105). Subsequently, the main control unit 10 performs control to output a millimeter wave signal to the sensor units 11 to 18 (step S106).

  Further, after the processing in step S105, the key-side control unit 8 determines whether or not the wireless communication unit 6 has received a response signal from the wireless communication unit 9 (step S107). When the response signal is received, the key control unit 8 determines whether or not the millimeter wave signal is received by the sensor receiving unit 7 (step S108).

  Here, the transmission control of the millimeter wave signal in the process of step S106 will be described.

  In this case, the main control unit 10, for example, from the front right detection sensor unit 11 to the front left detection sensor unit 12, the right front detection sensor unit 13, the right rear detection sensor unit 14, the left front detection sensor unit 15, The left rear detection sensor unit 16, the rear right detection sensor unit 17, and the rear left detection sensor unit 18 are controlled so that millimeter wave signals are output in order. At this time, the sensor units 11 to 18 output specific codes (for example, ID numbers) individually assigned as identification signals.

  As described above, since the key (key carrier) is located in the millimeter wave signal region RR1, the sensor receiving unit 7 receives the millimeter wave signal output from the front right detection sensor unit 11. Then, the key-side control unit 8 outputs a response signal indicating that the millimeter wave signal from the front right detection sensor unit 11 has been received based on the received unique code given to the front right detection sensor unit 11. (Step S109).

  Subsequently, when the wireless communication unit 9 receives the response signal from the wireless communication unit 6 (step S110), the main control unit 10 receives the millimeter wave signal received by the key-side wireless communication unit 2 based on the response signal. The output sensor unit (front right detection sensor unit 11) is specified.

  If the key has moved out of the millimeter wave signal region RR1 in step S110, step S106 is executed until a response signal is detected (step S111).

  Subsequently, the main control unit 10 performs control to output a millimeter wave signal again from the front right detection sensor unit 11. The front right detection sensor unit 11 outputs a millimeter wave signal and detects the reflected wave.

  The main control unit 10 calculates the position and size (key carrier) of a peripheral object from the reflected wave received by the front right detection sensor unit 11, and detects the detailed position of the key (key carrier) ( Step S112).

  Thereby, according to the present embodiment, the position of the key (key carrier) can be detected with high accuracy.

  Moreover, when the safety support system is provided in the automobile, the wireless key system 1 can be configured at low cost by using the millimeter wave radar used for the safety support system as the sensor units 11 to 18.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The present invention is suitable for a technique for detecting the position of a key (key carrier) in an automobile with high accuracy.

It is a block diagram which shows an example of the wireless key system by one embodiment of this invention. It is explanatory drawing which showed an example of the radio | wireless communication area | region covered by the radio | wireless key system of FIG. 1, and a millimeter wave signal area | region. 3 is a flowchart showing an operation example in the wireless key system of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio | wireless key system 2 Key side radio | wireless communication part 3 Car side radio | wireless communication part 4, 5 Antenna 6 Wireless communication part 7 Sensor receiving part 8 Key side control part 9 Wireless communication part (key detection part)
9a Antenna 10 Main control unit (key detection unit, key position calculation unit)
11 Front right detection sensor (position detection sensor)
11a Antenna 11b Sensor 11c Sensor control unit 12 Front left detection sensor unit (position detection sensor)
12a Antenna 12b Sensor 12c Sensor control unit 13 Right front detection sensor unit (position detection sensor)
13a Antenna 13b Sensor 13c Sensor control unit 14 Right rear side detection sensor unit (position detection sensor)
14a Antenna 14b Sensor 14c Sensor control unit 15 Left front detection sensor unit (position detection sensor)
15a Antenna 15b Sensor 15c Sensor control unit 16 Left rear detection sensor unit (position detection sensor)
16a Antenna 16b Sensor 16c Sensor control unit 17 Rear right detection sensor unit (position detection sensor)
17a Antenna 17b Sensor 17c Sensor control unit 18 Rear left detection sensor unit (position detection sensor)
18a Antenna 18b Sensor 18c Sensor control unit MR Wireless communication region RR1 to RR8 Millimeter wave signal region

Claims (5)

A key-side wireless communication unit that is provided in the key and outputs a wireless signal for recognizing the key;
An automobile-side wireless communication unit provided in the automobile,
The vehicle-side wireless communication unit is
A key detection unit that receives a radio signal of the key-side radio communication unit and detects that the key has approached the vehicle to an arbitrary distance;
A plurality of position detection sensor units that are provided at arbitrary positions of the automobile and transmit / receive position detection signals;
And a key position calculation unit that calculates a detailed position of the key using a position detection signal of the position detection sensor unit when the key detection unit detects the key. Wireless key system. The wireless key system according to claim 1, wherein
The sensor unit for position detection is
When the key detection unit detects the key, it transmits an identification signal individually given to each of the position detection sensor units,
The key side wireless communication unit is
When the identification signal of the position detection sensor unit is received, based on the received identification signal, a response signal indicating that the identification signal from which position detection sensor unit has been received is output,
The key position calculator is
A wireless key system that recognizes in which region of the vehicle the key is located from a response signal of the key-side wireless communication unit. The wireless key system according to claim 2, wherein
The key position calculator is
When recognizing in which region of the automobile the key is located, a position detection signal is transmitted from the position detection sensor unit corresponding to the recognized position among the plurality of position detection sensor units, A wireless key system, wherein the position and size of the object around the automobile are calculated from the reflected wave received by the position detection sensor unit, and the detailed position of the key is detected. The wireless key system according to any one of claims 1 to 3,
The wireless key system according to claim 1, wherein the position detection signal output from the position detection sensor unit is a millimeter wave signal. The wireless key system according to claim 3, wherein
The wireless key system, wherein the identification signal output from the position detection sensor unit is a millimeter wave signal.

Images