CN105425675A - Intelligent automobile relay box and control method thereof - Google Patents

Abstract

The invention provides an intelligent automobile relay box and a control method thereof. The intelligent automobile relay box comprises a single chip microcomputer, a current detection module, a relay control module, a power supply module and an alarm indication module. The single chip microcomputer is a core of a system. The control method is characterized in that under the condition that each relay is not in an overload state or the relay has no fault, actuation of the relay is completely controlled by an external switch signal; when a current is too large, the current detection module sends a signal to the single chip microcomputer, and the single chip microcomputer controls and disconnects a relay so that a purpose of protecting power supply security of a whole automobile is reached; when receiving an overload signal of the relay, the single chip microcomputer does not immediately disconnect the relay, there is one set protection time delay, and when a value is set to be zero, there is no delay. By using the relay box and the method, accurate monitoring of an automobile line current is realized; current grading management and protection of power used by an automobile are realized and there are three grades of a normal grade, a warning grade and a severe grade; the fault is prevented and simultaneously an automobile line and electric equipment are accurately protected.

Description

Automobile intelligent relay box and control method thereof

Technical field

The present invention relates to automobile intelligent relay box and control method, belong to technical field of automobile electronic control.

Background technology

Traditional AUTOMOTIVE RELAY box is that the relay wanted by automobile primary is arranged in a box together with fuse, and by external switch (such as firing key) pilot relay adhesive and disconnection, thus control automobile electrical equipment is powered.Each road relay connects fuse, and the effect of protection automobile electrical equipment is played in blown fuse when current is excessive.There are three large problems in traditional AUTOMOTIVE RELAY box use procedure: one be fuse is disposable, the instrument panel taking-up of can only disassembling a car of the fuse of damage is changed again; Two be fuse be only overload up to circuit unaffordable time just can work, can not to automobile electrical failure prevention in possible trouble; Three is the impacts owing to there is error and environment temperature in the quality of fuse or production run, and action of fuse electric current is inaccurate, does not sometimes have the effect of protection, causes automobile electrical equipment or wire harness to burn out or even self-burning of vehicle.

Along with socioeconomic develop rapidly and scientific and technical general advance, the develop rapidly of automobile cause, semiconductor transducer technology and microcontroller technology and people are to the further requirement of automotive safety.High precision electric current transducer can detect vehicle current on the one hand, can carry out intelligent decision on the other hand by microcontroller to electric current.Therefore, the present invention proposes and a kind ofly accurately can monitor automobile electrical electric current simultaneously in conjunction with the automobile intelligent relay box of Control.Remind driver to take precautions against in possible trouble when automobile line electric current is larger; disconnect relay when breaking down in time and disconnect the object reaching protection automobile electrical safety; automatically recover after Failure elimination and do not need to change any parts; each road current value and relay status data are sent to car load network by CAN communication interface simultaneously, realize data sharing.

Summary of the invention

Accurately monitor to realize automobile line electric current; realize automobile electrical current levels Management and Protection; be divided into normal, warning and serious three ranks, take precautions against fault and accurately protect automobile line and consumer again in possible trouble simultaneously, the present invention proposes automobile intelligent relay box and control method thereof.

Automobile intelligent relay box of the present invention, comprises single-chip microcomputer, current detection module, relay control module, power module,

Single-chip microcomputer comprises data processing module, timer input capture module, analog-to-digital conversion module, SPI communication interface module, switch signal acquisition module and CAN communication interface module,

Current detection module comprises current trigger comparison module and current sense module,

Relay control module comprises relay driving module and relay status detection module,

Single-chip microcomputer is the core in native system, timer input capture module wherein receives the signal from current trigger comparison module, SPI communication interface module sends instructions to current trigger comparison module, analog-to-digital conversion module receives the signal from current sense module and relay status detection module, switch signal acquisition module gathers external switch input, data processing module managing timer input capture module, analog-to-digital conversion module, SPI communication interface module, the data of switch signal acquisition module also output signal the adhesive of relay driving module pilot relay, data processing module realizes the communication with car load network by CAN communication interface module,

Power module, automobile 12V or 24V powers and converts that 5V is single-chip microcomputer, current detection module is powered to by this module.

The present invention also comprises and also comprises warning indicating module, and data processing module reminds driver by warning indicating module display current state when a failure occurs.State is divided into normally, warning and serious three ranks, respectively with green, yellow, red led instruction.

In the present invention, LM2596-5.0 is power module main control chip.

In the present invention, the model of single-chip microcomputer is MC9S12XS128MAL.

In the present invention, the control chip of current trigger comparison module is AD5611 and LM393.The control chip of relay driving module and warning indicating module is MC1413.

In the present invention, the current sensor chip of current sense module is ACS758LCB-050B.

The control method of automobile intelligent relay box of the present invention, in Shi Ge road relay nonoverload or the trouble-free situation of relay itself, the adhesive of relay is controlled by external switch signal completely.Current sense module detects the electric current of each road relay, and current trigger comparison module can be caused when current is excessive to transmit a signal to data processing module, and data processing module pilot relay driver module disconnects the object that relay reaches protection car load Electrical Safety.Data processing module sends data to current trigger comparison module by SPI communication interface module and arranges the size that electric current compares triggering, thus arranges the current value that relay disconnects protection.Data processing module not necessarily disconnects relay when receiving the signal of relay overload immediately, but there is the guard delay time that can arrange, and does not then postpone when this value is set to zero.

Beneficial effect: present invention achieves automobile line electric current and accurately monitor, achieves automobile electrical current levels Management and Protection, is divided into normally, warns and serious three ranks, takes precautions against fault and accurately protects automobile line and consumer again in possible trouble simultaneously.

Accompanying drawing explanation

Fig. 1 is automobile intelligent relay box theory diagram of the present invention.

Fig. 2 is switch quantity acquisition circuit figure.

Fig. 3 is CAN communication interface circuit figure.

Fig. 4 is relay driving module circuit diagram.

Fig. 5 is relay status detection module circuit diagram.

Fig. 6 is current sense module circuit diagram.

Fig. 7 is current trigger comparison module circuit diagram.

Fig. 8 is warning indicating module circuit diagram.

Fig. 9 power module circuitry figure.

Embodiment

Embodiment one: present embodiment is described below in conjunction with Fig. 1-Fig. 3, all functions in the Fig. 1 that realize, the type selecting of single-chip microcomputer is even more important; The present invention selects Freescale automotive grade 16 single-chip microcomputer MC9S12XS128MAL.This microcontroller bus clock, up to 40MHZ, possesses the timer passage of 8 passage input capture functions, has 16 passage high precision 12 figure place mode convertion interfaces, possesses the IO interface common more than 32 tunnels, be integrated with 1 tunnel CAN interface.Switch signal acquisition module gathers external switch input by the switch quantity acquisition circuit of Fig. 2, and Fig. 2 circuit high level is effective, is then judged as that external switch closes higher than 2.5V; Owing to have employed the design of backward dioded, the highest collection voltage can reach 100V; When voltage input is lower than then thinking during 0.8V that external switch does not close, CAN communication interface module is connected with external network or intelligent instrument by Special Interface Chip 82C250 in Fig. 3 and transmits data.

Embodiment two: present embodiment is described below in conjunction with Fig. 1, Fig. 4, Fig. 5, single-chip microcomputer, output pin be connected with the driving chip MC1413 in Fig. 4 and drive the control coil of relay, single-chip microcomputer exports high level then relay closes, and output low level relay disconnects.Relay status detection module detects the voltage of relay output end by RI7 and RI8 dividing potential drop in Fig. 5, and transmits the signal to analog-to-digital conversion module; Relation between the detection voltage of relay output voltage and relay status detection module meets formula

$Vj=\frac{RI7}{RI7+RI8}\×Vjout=\frac{2K}{20K+2K}\×Vjout=0\_909IVjout$

In formula, Vj is for detecting voltage, and Vjout is relay output voltage.

If relay work, should be close with system power supply voltage according to the Vjout that above formula is extrapolated by Vj during relay closes, relay disconnects Vj and equals zero, and therefore normally can not work by judging that relay has according to Vj.

Consider that the digital-to-analog conversion interface of single-chip microcomputer is limited, the present invention adopts simulation gating switch chip CD4051 to carry out dynamic sharing scanning to relay output voltage.

Embodiment three: present embodiment is described below in conjunction with Fig. 1, Fig. 6, Fig. 7, current sense module, adopt the current sensor chip ACS758LCB-050B in Fig. 6, relay output current arrives consumer through over-current sensor, current sensor export to flow through electric current be directly proportional (60mV/A) voltage signal and be sent to analog-to-digital conversion module,, voltage signal is converted into digital signal transmission data processing module and calculates current flow by analog-to-digital conversion module; The voltage signal that electric current is directly proportional that flows through sensed is sent to current trigger comparison module by current sense module simultaneously, current trigger comparison module adopts the voltage comparator chip LM2903 in Fig. 7, and the reference voltage produced with analog-digital chip AD5611 compares; LM2903 output low level under normal condition.When line current is excessive, the reference voltage that the voltage signal that current sense module exports produces higher than AD5611, LM2903 exports high level to timer input capture module, and timer input capture module produces interrupt event; Data processing module this interrupt event pilot relay that makes an immediate response disconnects and cuts off current return protection automobile line and consumer, and owing to being adopt the processing mode of interrupting, the response speed of the present invention to current overload is exceedingly fast; Data processing module not necessarily disconnects relay when receiving the signal of relay overload immediately; but there is the guard delay time that can arrange; this value does not then postpone when being set to zero; user can connect CAN and send instructions to data processing module; data processing module arranges by the chip AD5611 that SPI communication interface module sends data in current trigger comparison module the size that electric current compares triggering, thus arranges the current value that relay disconnects protection.

Embodiment four: present embodiment is described below in conjunction with Fig. 1, Fig. 8, warning indicating module, the driving chip MC1413 in Fig. 8 is adopted to drive green, yellow, red three pilot lamp, be connected with MC1413 by data processing module output pin, data processing module reminds driver by warning indicating module display current state when a failure occurs, state is divided into normally, warning and serious three ranks, respectively with green, yellow, red led instruction.

Embodiment five: present embodiment is described below in conjunction with Fig. 1, Fig. 9, power module, adopts the efficient DC-DC conversion chip LM2596-5.0 in Fig. 9, for other module of the present invention provides the operating voltage of 5V, LM2596-5.0 maximum input voltage is 36V, and maximum output current is up to 3A; Power module adopts chip LM2596-5.0 to make the present invention be applicable to gasoline car (12V) and diesel vehicle (24V) simultaneously.

Claims (7)

1. automobile intelligent relay box, is characterized in that, it comprises single-chip microcomputer, current detection module, relay control module, power module,

Single-chip microcomputer comprises data processing module, timer input capture module, analog-to-digital conversion module, SPI communication interface module, switch signal acquisition module and CAN communication interface module,

Current detection module comprises current trigger comparison module and current sense module,

Relay control module comprises relay driving module and relay status detection module,

Single-chip microcomputer is the core in native system, timer input capture module wherein receives the signal from current trigger comparison module, SPI communication interface module sends instructions to current trigger comparison module, analog-to-digital conversion module receives the signal from current sense module and relay status detection module, switch signal acquisition module gathers external switch input, data processing module managing timer input capture module, analog-to-digital conversion module, SPI communication interface module, the data of switch signal acquisition module also output signal the adhesive of relay driving module pilot relay, data processing module realizes the communication with car load network by CAN communication interface module,

Automobile 12V or 24V powers and converts 5V to by power module, for single-chip microcomputer, current detection module are powered.

2. automobile intelligent relay box according to claim 1, is characterized in that, also comprises warning indicating module, and when a failure occurs, data processing module reminds driver by warning indicating module display current state; State is divided into normally, warning and serious three ranks, respectively with green, yellow, red led instruction.

3. automobile intelligent relay box according to claim 1, is characterized in that, LM2596-5.0 is power module main control chip.

4. the automobile intelligent relay box according to claim 1 or 2 or 3, is characterized in that, the model of single-chip microcomputer is MC9S12XS128MAL.

5. the automobile intelligent relay box according to claim 1 or 2 or 3, is characterized in that, the control chip of current trigger comparison module is AD5611 and LM393; The control chip of relay driving module and warning indicating module is MC1413.

6. the automobile intelligent relay box according to claim 1 or 2 or 3, is characterized in that, the current sensor chip of current sense module is ACS758LCB-050B.

7. based on a control method for automobile intelligent relay box described in claim 1, it is characterized in that, under each road relay nonoverload or the trouble-free situation of relay itself, the adhesive of relay is controlled by external switch signal completely; Current sense module detects the electric current of each road relay, and current trigger comparison module can be caused when current is excessive to transmit a signal to data processing module, and data processing module pilot relay driver module disconnects the object that relay reaches protection car load Electrical Safety; Data processing module sends data to current trigger comparison module by SPI communication interface module and arranges the size that electric current compares triggering, thus arranges the current value that relay disconnects protection; Data processing module not necessarily disconnects relay when receiving the signal of relay overload immediately, but there is the guard delay time that can arrange, and does not then postpone when this value is set to zero.