JP2015143057A - Physical quantity detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity detection device capable of reducing cost while ensuring redundancy, and responding in high speed.SOLUTION: A physical quantity detection device 22 comprises: a plurality of sensors 5, 6 having a plurality of detection parts 10-13 provided integrally for detecting physical quantities individually corresponding to each physical quantity, and slaves IC 8, 9; a plurality of masters IC 3, 4 provided corresponding to each physical quantity; signal lines 14-16 for connecting the slaves IC 8, 9 of each sensor 5, 6 and connecting the slaves IC 8, 9 and the masters IC 3, 4; and control means 2 for detecting each physical quantity on the basis of detection signals which include each master IC 3, 4, are detected by each detection part 10-13, and are input via each slave IC 8, 9, signal lines 14-16, and each master IC 3, 4. The sensors are connected by the signal lines in series, and the connected sensors on both ends are directly connected to the masters IC by the signal lines.

Description

  The present invention relates to an apparatus for detecting a side collision of a vehicle by detecting a physical quantity.

  As disclosed in Patent Document 1, a vehicle has a pressure sensor for detecting an air pressure in an internal space formed in a side door as a sensor for transmitting a signal for deploying an airbag as an occupant protection device, and A And an acceleration sensor disposed on the pillar, the B pillar, and the C pillar.

  In order to ensure redundancy, these sensors are generally connected to the communication IC of the airbag ECU by wire harnesses as individual LAN cables that individually connect the pressure sensors and the acceleration sensors.

  Further, if the viewpoint of redundancy is eliminated, the pressure sensor and the acceleration sensor can be connected to the communication IC with the same wire harness.

European Patent Application Publication No. 1995125

  However, in the above-described prior art, since the sensors detect individual physical quantities, the number of the sensors increases, and the sensors are arranged apart from each other. There is a problem that the air bag deployment time is delayed. Moreover, since the pressure sensors and the acceleration sensors are separately connected, the number of wire harnesses is increased. In the case where the pressure sensor and the acceleration sensor are connected by the same wire harness, the number of wire harnesses is reduced, but there is a problem that all communication stops when the wire harness is disconnected even at one location.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a physical quantity detection device that can reduce the cost and enable a high-speed response while ensuring redundancy.

  The invention according to claim 1, which has been made to achieve the above object, is a physical quantity detection device (22) for detecting a plurality of physical quantities of different types, wherein a plurality of physical quantity detection apparatuses individually detect them corresponding to the physical quantities. And a plurality of sensors (5, 6) having slave ICs (8, 9), and a plurality of master ICs (3, 3) provided corresponding to the physical quantities, respectively. 4) and the signal lines (14˜) connecting the slave ICs (8, 9) of the sensors (5, 6) and the slave ICs (8, 9) and the master ICs (3, 4). 16) and each of the master ICs (3, 4), and detected by each of the detection units (10-13), the slave ICs (8, 9), the signal lines (14-16), and the masters Based on detection signal input via IC (3, 4) Control means (2) for detecting each physical quantity, wherein the sensors are connected in series by the signal lines, and the sensors at both ends connected to the master IC are connected to the signal lines. It is characterized by being directly connected by.

  According to this configuration, the plurality of sensors (5, 6) are integrally provided with a plurality of detection units (10 to 13) that individually detect them corresponding to a plurality of physical quantities and are slave ICs (8, 6). 9), a plurality of master ICs (3, 4) are provided corresponding to each physical quantity, and signal lines (14 to 16) are connected to slave ICs (8, 9) of each sensor (5, 6) and slaves. The IC (8, 9) and the master IC (3, 4) are connected, and the control means (2) includes each master IC (3, 4) and is detected by each detector (10-13) and each slave IC. (8, 9), each physical quantity is detected based on the detection signal input via the signal lines (14-16) and each master IC (3, 4). That is, the sensors (5, 6) are connected in series by signal lines (14-16), and the sensors (5, 6) at both ends connected to the master IC (3, 4) They are directly connected by lines (14, 16).

  Therefore, the redundancy and reliability of the change detection of the physical quantity is ensured, and the cost can be reduced by reducing the number of sensors and the number and length of the wire harnesses. Furthermore, since the detection units of the sensors are arranged close to each other, there is an excellent effect that the airbag deployment can be started at high speed without causing a delay in the detection time of the collision at each detection unit. In addition, since the sensors at both ends of the signal lines connected in series are directly connected to the master IC, communication with the control means is not interrupted even when a connection abnormality occurs in the signal lines. Since one master IC connected to a signal line free from connection abnormality can recognize a communicable sensor, there is an excellent effect that the position of the signal line where the connection abnormality occurs can be specified.

It is a top view which shows the arrangement | positioning form when the physical quantity detection apparatus of this invention is applied to the vehicle side collision detection apparatus. It is a block diagram which shows the structure of the vehicle side collision detection apparatus. It is an operation | movement logic diagram when applying the vehicle side collision detection apparatus to the airbag expansion start of a vehicle. It is a flowchart when diagnosing the connection abnormality of a wire harness.

  Hereinafter, an embodiment in which a physical quantity detection device of the present invention is applied to a vehicle side collision detection device will be described with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals.

  The vehicle side collision detection device 22 of the present embodiment is a device that detects a collision (hereinafter referred to as a side collision) on a side surface of a vehicle door or the like by detecting a change in a physical quantity at a side portion of the vehicle. As shown in FIGS. 1 and 2, the vehicle 1 is mounted.

  The airbag ECU 2 as the control means is disposed in the front of the vehicle 1 in the vehicle interior. The airbag ECU 2 is connected to other ECUs via CAN, which is one standard of a local area network (LAN).

  The airbag ECU 2 includes second master ICs 3 and 4. The master ICs 3 and 4 are IC elements for causing communication with the slave ICs 8 and 9 provided in the sensors 5 and 6.

  A wire harness 14 as a signal line is laid between the master IC 3 and the slave IC 8, and a wire harness 16 as a signal line is laid between the master IC 4 and the slave IC 9.

  A wire harness 15 as a signal line is laid between the slave IC 8 and the slave IC 9.

  The wire harnesses 14, 15 and 16 constitute a sensor LAN based on a protocol different from that of the airbag ECU 2. As the sensor LAN, a one-wire or two-wire signal line is preferably adopted, but the wire harnesses 14, 15, and 16 are preferably two-wire and are twisted pair cables (twisted pair cables). The wire harnesses 14, 15, and 16 are appropriately taped and have connectors at both ends.

  The sensor 5 includes a slave IC 8, a pressure detection unit 10, and an acceleration detection unit 11 that are integrated and packaged, and is disposed in an internal space formed in the front seat door of the vehicle 1. The slave IC 8 is connected to the pressure detection unit 10 and the acceleration detection unit 11 that are provided close to each other on the board on which the slave IC 8 is mounted.

  The sensor 6 includes a slave IC 9, a pressure detection unit 12, and an acceleration detection unit 13 that are integrated into a package, and is arranged in an internal space formed in the rear seat door of the vehicle 1. The slave IC 9 is connected to the pressure detection unit 12 and the acceleration detection unit 13 that are provided close to each other on the board on which the slave IC 9 is mounted.

  Thus, the sensors 5 and 6 are connected in series by the wire harnesses 14, 15, and 16, and the connected sensors 5 and 6 are connected to the master ICs 3 and 4 by the wire harnesses 14 and 16. Each is directly connected.

  The above-described sensors 5 and 6 have been described as individually detecting two different physical quantities such as pressure and acceleration, but are further provided with a detection unit that detects different physical quantities such as sound and temperature. It is good. In that case, sensors, slave ICs, and master ICs are also added. Further, the addition of the sensor is performed such that the sensor is inserted in the middle of the wire harness 15 that connects the sensors, including the case where the sensor detects the second physical quantity.

  The slave IC 8 converts the pressure value detected by the pressure detection unit 10 into serial data, attaches an identification code such as [1, 1] to the head of the data, and places the data on the sensor LAN. Further, the slave IC 8 converts the pressure value detected by the acceleration detection unit 11 into serial data, and places the identification code such as [1, 0] at the head and places it on the sensor LAN.

  Further, the slave IC 9 converts the pressure value detected by the pressure detection unit 12 into serial data, attaches an identification code such as [1, 1] to the head of the pressure data, and places it on the sensor LAN. Further, the slave IC 9 converts the pressure value detected by the acceleration detection unit 13 into serial data, attaches an identification code such as [1, 0] to the head, and puts it on the sensor LAN.

  The master IC 3 acquires only the data of the identification code [1, 1] from the sensor LAN, and outputs it as a pressure signal to the airbag ECU 2 as indicated by a broken line in FIG.

  The master IC 4 acquires only the data of the identification code [1, 0] from the sensor LAN, and outputs it as an acceleration signal to the airbag ECU 2 as indicated by a broken line in FIG.

  As described above, since the physical quantities to be detected are two types of pressure and acceleration, the number of sensors 5, 6, slave ICs 8, 9, and master ICs 3, 4 is also two. Even when the physical quantity to be detected is increased, the number of slave ICs is two.

  As shown in FIG. 1, the pole 7 is for simulating a side collision to a utility pole, a standing tree, a bridge railing, a traffic light, and the like.

  As shown in FIG. 3, when the vehicle 1 collides with the pole 7, the airbag ECU 2 receives a predetermined pressure signal from the pressure detection unit 10 that detects the air pressure in the internal space formed in the front seat door. When the threshold value is exceeded, “front door pressure” 17 is turned ON. When the acceleration signal of the acceleration detection unit 11 that detects the acceleration of the front seat door exceeds a predetermined second threshold value, the “acceleration of the front seat door” 18 is turned ON. When both “front seat door pressure” 17 and “front seat door acceleration” 18 are turned on, “airbag deployment” 21 is turned on, and an airbag (not shown) is deployed.

  Further, as shown in FIG. 3, when the vehicle 1 collides with the pole 7, the airbag ECU 2 receives a predetermined pressure signal from the pressure detector 12 that detects the air pressure in the interior space formed in the rear seat door. When the third threshold value is exceeded, the “rear seat door pressure” 19 is turned ON. When the acceleration signal of the acceleration detector 13 for detecting the acceleration of the rear seat door exceeds a predetermined fourth threshold value, the “acceleration of the rear seat door” 20 is turned ON. When both “rear seat door pressure” 19 and “rear seat door acceleration” 20 are turned on, “airbag deployment” 21 is turned on, and an airbag (not shown) is deployed.

  By the way, when a connection abnormality such as disconnection or contact failure occurs in one of the wire harnesses 14, 15, 16, the airbag ECU 2 compares data in the master IC 3 and the master IC 4 by the same detection unit. Thus, it is possible to self-diagnose which wire harness is abnormal in connection. An example of this diagnosis method will be described based on the flowchart of FIG.

  Each of the detection units 10 to 13 detects each physical quantity, and each of the slave ICs 8 and 9 transmits the physical quantity data on the wire harnesses 14, 15 and 16 (S 1). The airbag ECU 2 determines whether or not the physical quantity data acquired by the master IC 3 and the master IC 4 are the same (S2). When the physical quantity data acquired by the master IC 3 and the master IC 4 are the same, it is determined that all the wire harnesses 14, 15, 16 are normal (S7). When the physical quantity data acquired by the master IC 3 and the master IC 4 are not the same, it is determined that one of the wire harnesses 14, 15 and 16 has a connection abnormality (S3). Next, it is determined whether only the master IC 3 can acquire all physical quantity data (S4). When only the master IC 3 can acquire all physical quantity data, it is determined that there is a connection abnormality in the wire harness 16 (S10). When only the master IC 3 cannot acquire all physical quantity data, it is determined whether only the master IC 4 can acquire all physical quantity data (S5). When only the master IC 4 can acquire all physical quantity data, it is determined that there is a connection abnormality in the wire harness 14 (S9). Further, when it is determined that one of the wire harnesses 14, 15, 16 has a connection abnormality, each master IC 3, 4 can acquire only the physical quantity data of the detection unit of one of the sensors 5, 6. Is determined (S6). When each of the master ICs 3 and 4 can acquire only the physical quantity data of the detection part of one of the sensors 5 and 6, it is determined that there is a connection abnormality in the wire harness 15 (S8).

  Even when a connection abnormality occurs in the wire harness 15, the wire harness 14 or the wire harness 16 is connected to the sensor 5 or the sensor 6, respectively, so that one of the physical quantity data at different positions of the vehicle 1 is It is transmitted to the airbag ECU 2. That is, in FIG. 3, the logical OR of one of “front seat door pressure” 17 and “front seat door acceleration” 18, “rear seat door pressure” 19 and “rear seat door acceleration” 20 becomes effective. ing. Therefore, the redundancy of determining with two or more different physical quantities is ensured, and no erroneous determination is made as a collision. As a result, unnecessary deployment of the airbag can be prevented.

  As is clear from the above detailed description, the vehicle side collision detection device 22 that detects a plurality of different physical quantities according to the present embodiment has a plurality of detection units 10 that individually detect them corresponding to each physical quantity. To 13 and a plurality of sensors 5 and 6 including slave ICs 8 and 9, a plurality of master ICs 3 and 4 provided corresponding to each physical quantity, and the slave ICs 8 and 9 of the sensors 5 and 6 The signal lines 14 to 16 connecting the slave ICs 8 and 9 and the master ICs 3 and 4 and the master ICs 3 and 4 are detected by the detection units 10 to 13 and are detected by the detection units 10 to 13. And a control means 2 for detecting each physical quantity based on a detection signal input via each master IC 3, 4, and the sensors 5, 6 are connected in series by signal lines 14-16. ,And, Sensors 5 and 6 of the connection has been both ends are directly connected by signal lines 14 and 16 to the master IC3,4.

  Therefore, the redundancy and reliability of the physical quantity change detection are ensured, and the number of sensors and the number and length of the wire harnesses are reduced. Furthermore, since the detection units of the sensors are arranged close to each other, there is an excellent effect that the airbag deployment can be started at high speed without causing a delay in the detection time of the collision at each detection unit. In addition, since the sensors at both ends of the wire harness connected in series are directly connected to the master IC, communication with the control means is not interrupted even when a connection abnormality occurs in the wire harness. One master IC connected to the wire harness having no connection abnormality can recognize a communicable sensor. Therefore, the wire harness in which the connection abnormality has occurred can be identified, and when the operation is defective, it can be repaired only by replacing the defective wire harness without requiring replacement of the entire physical quantity detection device.

  In addition, this invention includes what can be implemented in the aspect which added various change, correction, improvement, etc. based on the knowledge of those skilled in the art. Further, it goes without saying that any of the embodiments to which the above-mentioned changes are added is included in the scope of the present invention without departing from the gist of the present invention.

1 vehicle 2 airbag ECU (control means)
3,4 Master IC
5,6 Sensor 8,9 Slave IC
10-13 Detection unit 14-16 Wire harness (signal line)
22 Vehicle side collision detection device (physical quantity detection device)

Claims (1)

A physical quantity detection device (22) for detecting a plurality of physical quantities of different types,
A plurality of detection units (10 to 13) that individually detect the physical quantities corresponding to the physical quantities, and a plurality of sensors (5, 6) including a slave IC (8, 9),
A plurality of master ICs (3, 4) provided corresponding to the physical quantities;
Signal lines (14 to 16) connecting the slave ICs (8, 9) of the sensors (5, 6) and the slave ICs (8, 9) and the master ICs (3, 4);
Each of the slave ICs (8, 9), each of the slave ICs (8, 9), each of the signal lines (14-16), and each of the master ICs (3, 3) is detected by each of the detection units (10-13). 4) control means (2) for detecting each physical quantity based on the detection signal input via
The sensor is connected in series by the signal line, and the sensors at both ends connected to the sensor are directly connected to the master IC by the signal line.

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