JP2009241908A - Navigation-cooperative traveling control device - Google Patents

Abstract

【Task】
If an existing unit whose hardware is fixed is to be incorporated into a system of the prior art, there is a problem that it is very troublesome and costly.
[Solution]
The travel control device includes a broadcast unit that transmits a broadcast value that is a trigger for synchronization via a network, a plurality of recognition units that transmit a measurement value obtained by measuring the environment of the outside world via a network, and a plurality of Based on the measurement results received from each of the recognition units, a determination unit that determines whether or not to control the vehicle is provided. Each of the plurality of recognition units determines the broadcast value and the measurement value as the measurement value. The determination unit, for each of the plurality of recognition units, based on the measurement value, the timer value, and the time step received from each of the plurality of recognition units, Absolute times that serve as a reference for each of the plurality of recognition units are calculated, and it is determined whether or not to control the vehicle based on the absolute times.
[Selection] Figure 2

Description

  The present invention relates to a travel control device that realizes a simple synchronization method.

  When trying to obtain results by using the measurement values of a plurality of sensors in a vehicle, the value of the sensor and the value of the measurement time are important.

  Here, when the central unit issues a command to other units all at once, and each unit receives the command from the network, each unit starts processing such as measurement, and after the processing is completed There is a technology for transmitting measurement data. In addition, there is a technology in which each unit has an internal timer, and a time stamp is attached at the end of measurement and transmitted to the network. Furthermore, there is a technique that includes a unit for applying a trigger (command) by combining the above two techniques and attaches a time stamp to the measurement data of each unit (see Patent Document 1). Thereby, in the unit which received each measurement data, it can be judged at what time data.

JP 2006-316739 A

  According to Patent Document 1, in order to match the measurement times between a plurality of units, it is necessary to design the timer specifications (timer increments) of each unit in advance. However, if another existing unit is to be connected to the existing network, it cannot be connected because the specification of the timer value is different. For example, when trying to connect an existing unit with a low computing capacity, the timer increments as much as the existing unit may not be realized, and a new hardware design may be required. That is, there is a problem that it is very troublesome and costly to install an existing unit whose hardware has been determined in a system of the prior art.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a travel control device for incorporating a synchronization method only by software change into an existing unit with a determined hardware configuration.

  In order to solve the above problems, one of the desirable embodiments of the present invention is as follows.

  The travel control device includes a broadcast unit that transmits a broadcast value that is a trigger for synchronization via a network, a plurality of recognition units that transmit a measurement value obtained by measuring the environment of the outside world via a network, and a plurality of Based on the measurement results received from each of the recognition units, a determination unit that determines whether or not to control the vehicle is provided. Each of the plurality of recognition units determines the broadcast value and the measurement value as the measurement value. A determination unit is provided for each of the plurality of recognition units based on the measurement value, the timer value, and the time step received from each of the plurality of recognition units. Absolute times that serve as a reference for each of the plurality of recognition units are calculated, and it is determined whether or not to control the vehicle based on the absolute times.

  ADVANTAGE OF THE INVENTION According to this invention, the traveling control apparatus for incorporating a synchronous system only in software change to the existing unit by which the hardware constitution was decided can be provided.

  Examples will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram.

  In this embodiment, it is composed of a broadcast unit (navigation device) that transmits a signal that triggers synchronization (hereinafter referred to as a broadcast value) to each unit, a plurality of control units, and a network that connects the units. .

  Each unit has a timer function for counting time and a function for transmitting and receiving data via a network.

  Each of the plurality of recognition units (sensors) 120 performs processing such as measurement, and transmits the result via a network. Each recognition unit may have the same function, or may have a different function.

  The determination unit 130 receives the result of each recognition unit and performs determination processing such as warning and braking. The function of the determination unit 130 may be stored in the broadcast unit 110 or the recognition unit 120.

  Actuator 140 operates the vehicle based on a command from the determination unit.

  The network 150 is, for example, a CAN (Controller Area Network).

  FIG. 2 is a diagram showing a time chart.

  The broadcast unit 110 transmits a broadcast value to each unit at the broadcast time. The broadcast value includes the ID of the broadcast, and uses time information at the time of transmission as an example.

  Here, the recognition unit 120 measures the distance to the obstacle ahead of the vehicle. First, the recognition unit 120-1 transmits a measurement value (distance data) at the time when the distance is measured and confirmed ((1) in FIG. 2A). Similarly, the recognition unit 120-2 transmits the measurement value at the time point (2) in FIG. 2A, and the recognition unit 120-3 transmits the measurement value at the time point (3) in FIG.

  At the time of these transmissions, transmission data is transmitted by adding the broadcast value received from the broadcast unit 110, the timer value (time when the measurement value is determined), and the timer time increment to the measurement value (FIG. 2). (C)).

  Here, the time increment indicates a minimum unit for counting time (about 1 microsecond to about 100 milliseconds). Since it is determined for each recognition unit, for example, even if the time unit of the recognition unit 120-1 is 1 microsecond, it may be 1 millisecond in the recognition unit 120-2.

  The determination unit 130 receives the transmission data from each recognition unit, calculates the absolute time (broadcast value + timer value × time increment) as a reference for the plurality of recognition units, and arranges the time axes in a unified manner (FIG. 2 (B)).

  Thus, by unifying the time axis using the broadcast value, the timer value, and the time increment, the time axis of the data measured by each recognition unit can be adjusted. For example, the distance (3) value can be detected several times or more to determine a forward obstacle, but the distance value is (3) (1) (2) using the values of a plurality of recognition units. It is possible to perform an early determination process such as determining a forward obstacle at the same time.

  Furthermore, by setting the time step for each recognition unit and calculating the absolute time by the determination unit 130, the difference in the width of the minimum timer due to the difference between the units can be absorbed. As a result, the existing hardware can be used as one recognition unit without changing the existing hardware.

  FIG. 3 is a diagram illustrating the configuration of the recognition unit.

  The recognition unit includes a communication I / O 310, a sensing I / O 320, a CPU 330, a RAM 340, a flash ROM 350, a hard timer 360, and a transmitter 370.

  The communication I / O is connected to a network and transmits / receives data.

  The sensing I / O measures the AD conversion unique to the recognition unit, the distance to the obstacle, the relative speed, and the like. Includes radio or optical devices.

  The CPU performs necessary recognition processing and the like in response to the sensing I / O input, and transmits the recognition result to the network via the communication I / O.

  The RAM is used as a program work area.

  The flash ROM stores a control unit program.

  The hard timer is a hardware timer that operates based on a transmitter. It is used as an interrupt process periodically started by the CPU and a timer for time measurement.

  FIG. 4 is a diagram illustrating processing of the recognition unit.

  The CPU 330 receives the broadcast value from the broadcast unit 110 via the communication I / O 310 and stores it in the RAM 340 (S410). Next, the timer that counts using a hard timer or an interrupt is cleared and restarted (S420). Next, a measurement process is performed and a measured value is determined (S430). Next, the measured value, the broadcast value, the timer value, and the time increment of the used timer are stored in the RAM (S440). Then, the RAM value is transmitted to the network via the communication I / O (S450).

  FIG. 5 is a diagram illustrating a time adjustment process of the determination unit 130.

  The determination unit 130 receives the measurement value, broadcast value, timer value, and time increment transmitted from each recognition unit (S510). Next, the absolute time is obtained (S520), and the absolute time and the measured value are stored in the RAM (S530). Next, a determination is made from the absolute time and measured value of each recognition unit (S540).

  For example, if the distance between the obstacles obtained by the two recognition units is substantially the same, the determination is used for alarming. The purpose of this is to determine the presence of an obstacle earlier with two recognition units than with one recognition unit.

  According to the present embodiment, since the synchronization method is realized mainly by software change, it is possible to realize a synchronization system and a control unit that are cheaper and have a shorter delivery time than when new hardware is created. In addition, since the existing hardware configuration is diverted, the amount of specification change can be reduced and the development risk can be reduced.

  Furthermore, the navigation device can transmit information such as time, topography and the like to the control unit of the vehicle, and can simultaneously play the role of a central unit for synchronization. At this time, the addition of functions to the navigation device can be handled mainly by software functions, so the function of the broadcast unit can be realized at low cost. That is, a new unit that acquires and broadcasts time can be omitted.

System Configuration. Time chart. The block diagram of a recognition unit. The figure which shows a judgment unit time adjustment process. The figure which shows the process of a recognition unit.

Explanation of symbols

110 Broadcast unit 120 Recognition unit 130 Judgment unit 140 Actuator 150 Network

Claims (5)

A broadcast unit that sends a broadcast value that triggers synchronization via the network,
A plurality of recognition units that transmit measurement values obtained by measuring the environment of the outside world via the network; and
A determination unit that determines whether to control the vehicle based on the measurement values received from each of the plurality of recognition units;
Each of the plurality of recognition units transmits the measurement value with the broadcast value, a timer value indicating the time when the measurement value is determined, and a time step added thereto,
The determination unit is an absolute reference for each of the plurality of recognition units for each of the plurality of recognition units based on the measurement value, the timer value, and the time step received from each of the plurality of recognition units. A travel control device that calculates time and determines whether or not to control the vehicle based on the absolute time.   The travel control device according to claim 1, wherein the time increment indicates a minimum unit for counting time.   The travel control device according to claim 1, wherein the determination unit arranges absolute times for the plurality of recognition units on a time axis.   The travel control device according to any one of claims 1 to 3, further comprising an actuator that controls the vehicle based on a determination result received from the determination unit.   The travel control device according to any one of claims 1 to 4, wherein the broadcast unit is a navigation device.

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