JP2015178331A - On-vehicle equipment control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle equipment control system in which fluctuation of input voltage of each of a plurality of pieces of on-vehicle equipment connected with a power supply line of local network configuration by influencing each other is suppressed without increasing the number of components.SOLUTION: An on-vehicle equipment control system 100 is a local network type on-vehicle equipment control system in which lines for connecting a controller 110 with pieces of on-vehicle equipment 121-124 is constituted of a main line 10 which is connected with the controller 110, and branch lines 21-24 which connect the main line 10 with the respective pieces of on-vehicle equipment 121-124. In the on-vehicle equipment control system 100, mutual influence of a plurality of pieces of on-vehicle equipment 121-124 on input voltage can be relieved by making resistance of the main line 10 smaller to make resistance of the branch lines 21-24 larger.

Description

  The present invention relates to a local network type in-vehicle device control system in which a plurality of in-vehicle devices are connected to a trunk line connected to a control device through respective branch lines.

  As a system configuration for connecting a plurality of computers, a local area network (LAN) is known. Patent Document 1 discloses a system configuration in which a plurality of devices mounted on a vehicle are connected with a configuration similar to a LAN. It is disclosed. In Patent Document 1, a plurality of in-vehicle devices are connected to a device local network, and this device local network is connected to the control device via the in-vehicle local network.

  The wire harness constituting the device local network includes a control line for transmitting a control signal and a power line for supplying power to each in-vehicle device. Patent Document 1 describes that a control device and an in-vehicle device are connected via an in-vehicle local network and an in-device local network via a communication device, and protocol conversion is performed by the communication device.

JP 2008-294503 A

  However, in Patent Document 1, power is supplied to each in-vehicle device via the wire harness of the device local network, but in such a configuration, when any of the in-vehicle devices starts an operation, for example, There arises a problem that the input voltage of other in-vehicle devices is affected. In particular, when the in-vehicle device is a lamp, the brightness changes due to a change in voltage drop every time another device operates, which may cause discomfort to the user or the like. If a circuit is added so as to suppress such fluctuations in voltage drop, the number of parts increases and the cost increases.

  The present invention has been made to solve these problems, and without increasing the number of parts, a plurality of in-vehicle devices connected to the power supply line in the local network configuration affect each other, and each input voltage is affected. An object of the present invention is to provide an in-vehicle device control system that suppresses fluctuations.

  A first aspect of the in-vehicle device control system according to the present invention is an in-vehicle device that includes a local network type power supply line configured by connecting two or more in-vehicle devices with respective branch lines to a trunk line connected to a control device. In the device control system, the trunk line and the branch line have at least a power line and a ground line, and the input voltage of the in-vehicle device is lower than the battery voltage by a predetermined value or more, so that the trunk line The resistance value of the power line and the ground line and the resistance value of the power line and the ground line of the branch line are set, and the resistance value of the power line and the ground line of the main line is set as the resistance of the power line and the ground line of the branch line. It is characterized by being smaller than the value.

  In another aspect of the in-vehicle device control system of the present invention, the resistance values of the power line and the ground line of the trunk line vary in a voltage drop amount at a connection point with the branch line due to a change in an operating state of the in-vehicle device. Is set to be equal to or less than the first threshold, and the resistance values of the power line and the ground line of the branch line are such that each input voltage of the in-vehicle device is greater than or equal to the second threshold and less than or equal to the third threshold with respect to the battery voltage It is set so that it may become a voltage drop.

  In another aspect of the in-vehicle device control system of the present invention, the first threshold is 0.5V, and the second threshold and the third threshold are 1V and 2V, respectively.

  Another aspect of the in-vehicle device control system of the present invention is characterized in that a variable resistor is connected to each of the power line and the ground line of the branch line.

  In another aspect of the in-vehicle device control system of the present invention, the resistance value of the power line and the ground line of the branch line is adjusted by any one of the length of the branch line, the diameter of the branch line, and the material of the branch line. It is characterized by.

  Another aspect of the in-vehicle device control system of the present invention is characterized in that the in-vehicle device is a lamp.

  According to the present invention, there is provided an in-vehicle device control system in which a plurality of in-vehicle devices connected to a power supply line having a local network configuration are mutually influenced and each input voltage is prevented from fluctuating without increasing the number of parts. It becomes possible to provide.

It is a block diagram which shows the structure of the vehicle equipment control system of 1st Embodiment of this invention. It is a graph which shows the time change of the input voltage of a tail lamp. It is a graph which shows the change of the light beam with respect to the input voltage of a general lamp. It is a block diagram which shows the structure of the vehicle equipment control system of another embodiment of this invention. It is a block diagram which shows the structure of the vehicle equipment control system of another embodiment of this invention.

  An in-vehicle device control system according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. In addition, about each structural part which has the same function, the same code | symbol is attached | subjected and shown for simplification of illustration and description.

(First embodiment)
An in-vehicle device control system according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the in-vehicle device control system 100 of the present embodiment. The in-vehicle device control system 100 includes a control device 110 mounted on a vehicle and a plurality of in-vehicle devices 121 to 124 controlled by the control device 110. Here, the number of in-vehicle devices is 121 to 124, but is not limited to this, and is applied to an in-vehicle device control system including two or more in-vehicle devices.

  In the in-vehicle device control system 100 according to the present embodiment, the line connecting the control device 110 and the in-vehicle devices 121 to 124 includes the main line 10 connected to the control device 110, the main line 10, and the in-vehicle devices 121 to 124. It is a local network type in-vehicle device control system composed of branch lines 21 to 24 that connect to each other.

  The trunk line 10 includes a trunk power line 10a, a trunk ground line 10b, and a trunk control line 10c. The branch lines 21 to 24 are configured by branch line power lines 21a to 24a, branch line ground lines 21b to 24b, and branch line control lines 21c to 24c, respectively. The branch line power lines 21a to 24a are connected to the main line power line 10a at connection points 31 to 34, respectively, and the branch line ground lines 21b to 24b are connected to the main line ground line 10b at connection points 31 to 34, respectively. Yes. Similarly, the branch line control lines 21c to 24c are connected to the main line control line 10c at connection points 31 to 34, respectively.

  As described above, in the in-vehicle device control system 100 in which the line is formed in the local network type, power is supplied from the control device 110 to the trunk line 10, and the in-vehicle devices 121 to 124 each have branch lines 21 to 124 as necessary. Power can be received from the trunk line 10 via 24. As a result, for example, when any of the in-vehicle devices 121 to 124 that have been stopped until then starts operating, a part of the current flowing through the trunk line 10 is supplied to the in-vehicle device side. The amount of voltage drop at each of the connection points 31 to 34 is larger than before the on-vehicle device is activated (the voltage at each of the connection points 31 to 34 is reduced).

  Thereby, each input voltage of in-vehicle devices 121-124 will fall, and when in-vehicle devices 122-124 are lamps, for example, the brightness of a lamp will fall by voltage drop, and a user will be uncomfortable. There is a risk of giving. Thus, when power is supplied to a plurality of in-vehicle devices with a local network type configuration, there is a problem in that the input voltages are mutually affected among the plurality of in-vehicle devices.

  As an example, FIG. 2 shows the influence of a voltage drop when the in-vehicle devices 121 to 124 include a tail lamp and a hazard lamp. FIG. 2 is a graph showing temporal changes in the input voltage of the tail lamp. The horizontal axis represents time, and the vertical axis represents the input voltage of the tail lamp. In FIG. 2, the tail lamp is switched on at time T1. Thereafter, at time T2, the hazard lamp is turned on, and the hazard lamp repeats turning on time S1 and turning off time S2.

  The input voltage of the tail lamp is substantially constant from time T1 when the switch is turned on to time T2 when the hazard lamp is turned on. On the other hand, after time T2 when the hazard lamp is turned on, it is shown that the input voltage of the tail lamp fluctuates as the hazard lamp blinks. That is, the input voltage of the tail lamp decreases every time the hazard lamp is turned on (time S1). Although the brightness of the tail lamp is normally maintained constant, the brightness of the tail lamp fluctuates by turning on the hazard lamp, which may cause discomfort to the user or the like.

  Therefore, the in-vehicle device control system 100 according to the present embodiment is configured to reduce as much as possible the plurality of in-vehicle devices 121 to 124 connected to the local network from affecting the input voltage. In the present embodiment, first, the amount of voltage drop in the main line 10 is reduced by reducing the resistance values of the main power line 10a and the main ground line 10b of the main line 10. By doing in this way, the change of the voltage by the position of the connection points 31-34 with the branch lines 21-24 in the trunk line 10 can be made small, and the variation between the voltages which can be supplied to the vehicle equipment 121-124 is made small. can do.

  More specifically, even if any of the in-vehicle devices 121 to 124 changes the operating state, the fluctuation amount of the voltage drop amount of the trunk line 10 at the connection points 31 to 34 with the in-vehicle devices 121 to 124 is equal to or less than the first threshold value. Thus, the resistance values of the main line power line 10a and the main line ground line 10b of the main line 10 are determined. The set value of the first threshold will be described later by taking the case where the in-vehicle devices 121 to 124 are lamps as an example.

  When the in-vehicle devices 121 to 124 are lamps, the brightness changes depending on the input voltage as shown in FIG. In FIG. 3, the horizontal axis represents the input voltage, and the vertical axis represents the luminous flux (value normalized by assuming that the luminous flux when 12V is applied to the lamp is 1). Shows how it will change. As shown in the figure, the lamps have such characteristics that when the input voltage is low, the change in the luminous flux due to the fluctuation in the input voltage is small, and as the input voltage increases, the change in the luminous flux due to the fluctuation in the input voltage becomes large. doing.

  Therefore, when the in-vehicle devices 121 to 124 have characteristics as shown in FIG. 3, the operating state of any of the in-vehicle devices 121 to 124 is changed by lowering the respective input voltages in advance, so that other in-vehicle devices Even if the input voltage of the devices 121 to 124 fluctuates, the influence on the respective outputs (lamp brightness, etc.) can be reduced. In addition, it is necessary to prevent the output value (for example, the brightness of the lamp) of the in-vehicle devices 121 to 124 from being lower than the reference value defined by the vehicle safety standard due to the decrease in the input voltage.

  In the present embodiment, the input voltage of the in-vehicle devices 121 to 124 is set lower by, for example, a predetermined voltage width than the battery voltage. In order to lower the input voltage, in this embodiment, the resistance values of the branch power lines 21a to 24a and the branch ground lines 21b to 24b of the branch lines 21 to 24 are increased. The resistance values of the branch line power supply lines 21a to 24a and the branch line ground lines 21b to 24b are determined so that the input voltages of the in-vehicle devices 121 to 124 are decreased from the predetermined battery voltage by the second threshold value to the third threshold value. Has been.

  The set values of the first to third threshold values can be determined as follows, for example. When the in-vehicle devices 121 to 124 are lamps, the brightness of the lamp is determined by the voltage drop in the main line 10 and the voltage drops in the branch lines 21 to 24 in consideration of the nonlinear output characteristics of the lamps shown in FIG. It is preferable to determine the first threshold value and the second threshold value so as not to cause discomfort to the person. As such setting values, in the present embodiment, the first threshold value is 0.5 V, and the second threshold value is 1 V. The set value of the third threshold is a value obtained by adding a margin to the guaranteed range of the input voltage to the lamp, and is 2 V here. As described above, the resistance values of the power supply line 10a and the ground line 10b of the trunk line 10 are preferably made smaller than the resistance values of the power supply lines 21a to 24a and the ground lines 21b to 24b of the branch lines 21 to 24.

  As described above, when the resistance value of the branch lines 21 to 24 is increased to increase the voltage drop amount in the branch lines 21 to 24, the non-linear output characteristics of the lamp due to the decrease of the input voltage of the in-vehicle devices 121 to 124. Accordingly, even if other in-vehicle devices operate, the influence on the brightness is reduced.

  As described above, in the in-vehicle device control system 100 according to the present embodiment, a plurality of in-vehicle devices 121 to 124 are input to each other by decreasing the resistance of the trunk line 10 and increasing the resistances of the branch lines 21 to 24. The influence on the voltage can be reduced. Further, when the in-vehicle devices 121 to 124 have the characteristics as shown in FIG. 3, the output fluctuations of the in-vehicle devices 121 to 124 are reduced by increasing the resistance of the branch lines 21 to 24 and lowering the input voltage. Can be made.

(Other embodiments)
An in-vehicle device control system according to another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram illustrating a configuration of an in-vehicle device control system 200 according to another embodiment. In the in-vehicle device control system 200 of the present embodiment, as means for increasing the resistance of the branch lines 21 to 24, variable resistances are provided for the branch power lines 21a to 24a and the branch ground lines 21b to 24b of the branch lines 21 to 24, respectively. The bodies 41 to 44 are arranged.

  The variable resistors 41 to 44 can be used to adjust the input voltages of the in-vehicle devices 121 to 124 so as to drop from a predetermined battery voltage by a second threshold value or more and a third threshold value or less. In FIG. 4, the variable resistors 41 to 44 are arranged on both the branch line power lines 21 a to 24 a and the branch line ground lines 21 b to 24 b of the branch lines 21 to 24. It can also be set as the form arrange | positioned only to either one of 24a and branch ground line 21b-24b.

  An in-vehicle device control system according to still another embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing a configuration of an in-vehicle device control system 300 of still another embodiment. In the in-vehicle device control system 300 of this embodiment, the length of each harness of the branch lines 21 to 24 is increased as means for increasing the resistance of the branch lines 21 to 24. By adjusting the length of the harness, each input voltage of the in-vehicle devices 121 to 124 can be lowered from a predetermined battery voltage by a second threshold value or more and a third threshold value or less. In FIG. 5, the lengths of both the branch power lines 21 a to 24 a and the branch ground lines 21 b to 24 b of the branch lines 21 to 24 are increased, but the branch power lines 21 a to 24 a and The length of only one of the branch ground wires 21b to 24b can be increased.

  In the said embodiment, although resistance value is adjusted with the length of the power supply lines 21a-24a and the ground lines 21b-24b of the branch lines 21-24, it is not limited to this, The wire diameter of the branch lines 21-24, Alternatively, the resistance value can be adjusted depending on the material.

  In addition, the description in this Embodiment shows an example of the vehicle equipment control system which concerns on this invention, and is not limited to this. The detailed configuration and detailed operation of the in-vehicle device control system according to the present embodiment can be appropriately changed without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Trunk line 10a Trunk line power line 10b Trunk line ground line 10c Trunk line control lines 21-24 Branch line 21a-24a Branch line power lines 21b-24b Branch line ground lines 21c-24c Branch line control lines 31-34 Connection point 41 -44 Variable resistor 100, 200, 300 In-vehicle device control system 110 Controller 121-124 In-vehicle device

Claims (6)

An in-vehicle device control system including a local network type power supply line configured by connecting two or more in-vehicle devices to each main line to a main line connected to a control device,
The trunk line and the branch line have at least a power line and a ground line,
While setting the resistance value of the power line and the ground line of the trunk line and the resistance value of the power line and the ground line of the branch line so that each input voltage of the in-vehicle device is lower than the battery voltage by a predetermined value or more,
The in-vehicle device control system, wherein resistance values of the power line and the ground line of the main line are made smaller than resistance values of the power line and the ground line of the branch line. The resistance value of the power line and the ground line of the main line is set so that the fluctuation amount of the voltage drop at the connection point with the branch line due to the change in the operating state of the in-vehicle device is equal to or less than the first threshold value.
The resistance values of the power line and the ground line of the branch line are set so that each input voltage of the in-vehicle device has a voltage drop of a second threshold value or more and a third threshold value or less with respect to the battery voltage. The in-vehicle device control system according to claim 1. The first threshold is 0.5V;
The in-vehicle device control system according to claim 2, wherein the second threshold value and the third threshold value are 1V and 2V, respectively. The in-vehicle device control system according to any one of claims 1 to 3, wherein a variable resistor is connected to each of the power line and the ground line of the branch line. The resistance value of the power line and the ground line of the branch line is adjusted by any one of the length of the branch line, the diameter of the branch line, and the material of the branch line. The in-vehicle device control system according to any one of claims. The on-vehicle device control system according to any one of claims 1 to 5, wherein the on-vehicle device is a lamp.

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