JP2016070679A - Vehicle navigation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To synchronize information used to implement a navigation function for vehicle travel guidance with a lower processing load.SOLUTION: A vehicle navigation apparatus 10 comprises: a plurality of sensors 13, 14 and 15 detecting information used to implement a navigation function for vehicle travel guidance; a sub-microcomputer 11 acquiring a plurality of pieces of information detected by the respective sensors and synchronizing and outputting the acquired information; and a main microcomputer 21 implementing the navigation function on the basis of the plurality of synchronized information which is output from the sub-microcomputer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle navigation apparatus that provides vehicle travel guidance.

  The vehicle navigation device detects the position and traveling direction of a vehicle by known dead reckoning navigation based on information such as an angular velocity detected by a gyro sensor, a vehicle speed detected by a vehicle speed sensor, and an acceleration detected by an acceleration sensor. . Then, the vehicle mark corresponding to the detection result is displayed on the display device together with the road map, so that the vehicle is guided to the driving vehicle (for example, see Patent Document 1).

Japanese Patent No. 3218876

  By the way, in order to detect a more accurate position and traveling direction of a vehicle, it is necessary to synchronize various information obtained from a plurality of sensors as much as possible. However, in the conventional configuration, a plurality of sensors output information to different microcomputers. Therefore, in order to synchronize various types of information obtained from a plurality of sensors, it is necessary to perform synchronization processing between a plurality of microcomputers, which increases the load of the synchronization processing.

  Therefore, the present invention provides a vehicle navigation apparatus that can synchronize information used for executing a navigation function for performing vehicle travel guidance with a smaller processing load.

  According to the vehicle navigation apparatus of the present invention, each of the plurality of sensors detects information used for executing a navigation function for performing vehicle travel guidance. The sub-microcomputer acquires information detected by the plurality of sensors, and outputs the acquired information in synchronization. The main microcomputer performs a navigation function based on a plurality of synchronized information output from the sub microcomputer.

  According to this configuration, various types of information obtained from a plurality of sensors are acquired by one sub-microcomputer, and a plurality of information is synchronized from the one sub-microcomputer and given to the main microcomputer. Therefore, as compared with the conventional technology that performs synchronization processing among a plurality of microcomputers, information used to execute a navigation function for performing vehicle travel guidance can be synchronized with a smaller processing load.

The figure which shows schematically the structural example of the navigation apparatus for vehicles which concerns on one Embodiment. Flow chart showing an operation example by the vehicle navigation device

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A vehicle navigation apparatus 10 illustrated in FIG. 1 includes a sub microcomputer 11 and a main microcomputer 21. Hereinafter, the vehicle navigation device 10 is simply referred to as a “navigation device 10”. The sub-microcomputer 11 is a dedicated microcomputer provided for the navigation device 10 and is mounted on the sub-board 12. The startup performance of the sub-microcomputer 11 is improved so that the sub-microcomputer 11 is started at least in a shorter time than the main microcomputer 21 when the accessory switch of the vehicle is turned on. The sub-microcomputer 11 is provided with a port 11a for acquiring detection information obtained by various sensors. In this case, the port 11a is composed of an A / D port. Further, the sub-microcomputer 11 is provided with a communication port 11b for performing communication with each element mounted on the main board 22.

  Information such as the angular velocity detected by the gyro sensor 13, the vehicle speed detected by the vehicle speed sensor 14, and the acceleration detected by the acceleration sensor 15 is input to the sub-microcomputer 11 through the port 11a. . In this case, the gyro sensor 13 and the acceleration sensor 15 are mounted on the sub board 12.

  The main microcomputer 21 is mounted on a main board 22 different from the sub board 12. The main microcomputer 21 is not provided with a port for acquiring detection information obtained by various sensors. That is, the main microcomputer 21 is composed of a general-purpose microcomputer that does not have a port for acquiring information from various sensors. The main microcomputer 21 is configured to be able to execute a navigation function for performing driving guidance of the vehicle to the driving vehicle by executing a control program for performing known dead reckoning navigation. The main microcomputer 21 is provided with a communication port 12b for communicating with the sub-microcomputer 11.

  In addition, a GPS module 23 and a connection abnormality detection sensor 24 are mounted on the main board 22. The GPS module 23 is an example of a position detection sensor, and detects the position of the vehicle based on radio waves received via an antenna 23a from a positioning satellite that constructs a positioning system (not shown). Then, the GPS module 23 outputs the detected position information to the sub-microcomputer 11 via the communication line 31. The connection abnormality detection sensor 24 detects whether or not the antenna 23 a is normally connected to the GPS module 23. Then, the connection abnormality detection sensor 24 outputs information indicating connection abnormality or normality to the sub-microcomputer 11 via the communication line 32.

  The navigation device 10 further includes a communication line 33 and a communication line 34. The communication line 33 is a dedicated communication line for transmitting a plurality of information synchronized by the sub-microcomputer 11 from the sub-microcomputer 11 to the main microcomputer 21 as will be described in detail later. For example, a UART cable (UART: Universal Asynchronous Receiver Transmitter) is employed as the communication line 33. The communication line 34 is used for transmission / reception of various information other than a plurality of information synchronized by the sub-microcomputer 11. For example, a USB cable (USB: Universal Serial Bus) is employed as the communication line 34.

  Next, an operation example of the navigation function executed by the navigation device 10 will be described. That is, as illustrated in FIG. 2, when the sub-microcomputer 11 receives information from the various sensors 13, 14, 15, and 23 (S 1: YES), a predetermined time has elapsed since the previous information transmission to the main microcomputer 21. It is confirmed whether or not it has passed (S2). The sub-microcomputer 11 stores information received from the various sensors 13, 14, 15, and 23 within the predetermined period in a storage medium (not shown). The predetermined time can be appropriately changed and set based on, for example, the accuracy of position information and traveling direction information required for vehicle travel guidance.

  If the predetermined time has elapsed (S2: YES), the sub-microcomputer 11 collects a plurality of pieces of information acquired from the various sensors 13, 14, 15, 23 within the predetermined time. The data is output to the microcomputer 21 (S3). As a result, the sub-microcomputer 11 synchronizes a plurality of pieces of information acquired within a predetermined time and gives them to the main microcomputer 21. Further, the sub-microcomputer 11 is configured to periodically execute processing given to the main microcomputer 21 by synchronizing a plurality of information. When the sub-microcomputer 11 transmits the information in synchronization, the sub-microcomputer 11 starts counting the elapsed time thereafter (S4), and proceeds to step S1.

  On the other hand, when the main microcomputer 21 receives a plurality of synchronized information from the sub-microcomputer 11 (M1: YES), the main microcomputer 21 executes a known navigation function based on the information group. That is, the main microcomputer 21 detects the position and traveling direction of the vehicle by a known dead reckoning method based on the received information group. And the vehicle mark corresponding to the detection result is displayed on a display device (not shown) together with the road map.

  According to the navigation device 10, various information obtained from the plurality of sensors 13, 14, 15, and 23 is directly acquired by one sub-microcomputer 11, and the plurality of information is synchronized from the one sub-microcomputer 11. It was made to give to the main microcomputer 21. That is, a plurality of pieces of information can be synchronized without performing a synchronization process between the plurality of microcomputers 11 and 21, and the load of the synchronization process can be reduced.

  Further, according to the navigation device 10, the dedicated communication line 33 for transmitting a plurality of information synchronized by the sub-microcomputer 11 to the main microcomputer 21 is provided. Therefore, the synchronized information can be reliably given to the main microcomputer 21.

  Further, according to the navigation device 10, the sub-microcomputer 11 periodically transmits a plurality of synchronized information to the main microcomputer 21. Therefore, the navigation function in the main microcomputer 21 can be executed accurately.

  Moreover, according to the navigation apparatus 10, the main microcomputer 21 is comprised by the general purpose microcomputer which can endure comparatively high processing load. Then, according to the navigation device 10, the navigation function is executed by the main microcomputer 21. That is, according to the navigation device 10, the navigation function with a relatively high processing load is executed by the main microcomputer 21, so that the navigation function can be executed without difficulty.

  According to the navigation device 10, the GPS module 23 is mounted on the same main board 22 as the main microcomputer 21. However, the GPS module 23 may be mounted on the same sub board 12 as the sub microcomputer 11, or may be mounted on the same board as a microcomputer other than the sub microcomputer 11 and the main microcomputer 21.

  The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the scope of the invention. For example, the sensor is not limited to the gyro sensor 13, the vehicle speed sensor 14, and the acceleration sensor 15 as long as it detects information used for realizing the navigation function of the vehicle.

  In the drawings, 10 is a vehicle navigation device, 11 is a sub-microcomputer, 13 is a gyro sensor (sensor), 14 is a vehicle speed sensor (sensor), 15 is an acceleration sensor (sensor), 21 is a main microcomputer, and 22 is a main board (main The same substrate as the microcomputer), 23 is a GPS module (sensor, position detection sensor), and 33 is a dedicated communication line.

Claims (5)

A plurality of sensors (13, 14, 15, 23) for detecting information used for executing a navigation function for performing vehicle travel guidance;
A sub-microcomputer (11) for acquiring a plurality of pieces of information detected by the sensors and outputting the acquired pieces of information in synchronization;
A main microcomputer (21) for executing a navigation function based on a plurality of synchronized information output from the sub-microcomputer;
A vehicle navigation apparatus comprising:   The vehicle navigation apparatus according to claim 1, further comprising a dedicated communication line (33) for transmitting the plurality of synchronized information from the sub-microcomputer to the main microcomputer.   The vehicle navigation device according to claim 1, wherein the sub-microcomputer periodically transmits the synchronized information to the main microcomputer.   The vehicle navigation apparatus according to any one of claims 1 to 3, wherein the main microcomputer is a general-purpose microcomputer that does not include a port for acquiring a plurality of pieces of information detected by the sensors. As the sensor, at least a position detection sensor (23) for detecting the position of the vehicle is provided,
The vehicle navigation apparatus according to any one of claims 1 to 4, wherein the position detection sensor is mounted on the same board (22) as the main microcomputer.

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