CN205836760U - A kind of active pretension seat belt controlling system - Google Patents

Abstract

A kind of active pretension seat belt controlling system, panel includes power circuit, single-chip microcomputer, motor-drive circuit, electromagnetic clutch drive circuit, sensor interface circuitry, communication serial port circuit, BDM download circuit and interface circuit.This utility model is by gathering the signal of each early warning sensor; the logical judgment utilizing singlechip controller determines level of security; and according to the difference of degree of danger; control command under the different level of security of output; motor is driven to control Webbing retractor retracting number of times and the value of thrust of belt-strap; by the integrated mode that both are different, determine corresponding level of security, it is ensured that human pilot is played and reminds and the function of protection.

Description

A kind of active pretension seat belt controlling system

Technical field

This utility model relates to a kind of active pretension seat belt controlling system.

Background technology

Now, seat belt is as the important component part in member's constrained system, and fact proved is most important And maximally effective safety device.The security performance of automobile is by predicting and evade danger Accident prevention in the automobile active of possible trouble Safety and the passive security composition that strick precaution driver and crew come to harm when a fault occurs.Seat belt is mainly used to when automobile runs into During fortuitous event brake hard, driver and crew are fettered on the seat, thus protect driver and crew to collide from secondary and cause wound Evil.According to multiple studies have shown that both at home and abroad, the fatigue driving of driver and violation operation are the main causes causing vehicle accident, account for To vehicle accident sum 75%.By to the detection of driver's driving states and providing relevant information to driver in time, can To efficiently reduce the generation of vehicle accident.Therefore, the research for seat belt is significant to running safety.Special Other, for seat belt research in terms of active safety, it is forward-looking and edification.

Traditional three-point safety belt and existing belt with pre-load device belong to the category of passive security, again due to existing Belt with pre-load device be after collision occurs, just to play purpose and the generation of pretension by built-in exploding gas propellant Gas-forming agent in collision rift device needs to change in time, it is impossible to meet the requirement of active safety, the most very well Play that precognition is dangerous, reduce dangerous function also greatly increases rear current cost.

Summary of the invention

In order to solve above-mentioned the deficiencies in the prior art, this utility model provides a kind of active pretension seat belt to control system System, it, by gathering the signal of each early warning sensor, utilizes the logical judgment of singlechip controller to determine level of security, and according to The difference of degree of danger, the control command under the different level of security of output, drive motor to control Webbing retractor retracting time Number and the value of thrust of belt-strap, by the integrated mode that both are different, determine corresponding level of security, it is ensured that to driver Member plays and reminds and the function of protection.

As above conceiving, the technical solution of the utility model is: a kind of active pretension seat belt controlling system, panel bag Include power circuit, single-chip microcomputer, motor-drive circuit, electromagnetic clutch drive circuit, sensor interface circuitry, communication serial port power Road, BDM download circuit and interface circuit；Described power circuit drives with single-chip microcomputer, motor-drive circuit, electromagnetic clutch respectively Circuit and sensor interface circuitry connect；Described single-chip microcomputer and BDM download circuit are bi-directionally connected and communication serial port circuit and interface Circuit both-way communication, the output port of single-chip microcomputer connects motor-drive circuit and electromagnetic clutch drive circuit, single-chip microcomputer defeated Inbound port receives the output signal of various sensor by sensor interface circuitry.

Described power circuit includes power supply input and power supply chip U1；Described power supply inputs successively through electric fuse F1 and two poles Pipe D1 connects the Vin+ pin of power supply chip U1, and the OUTPUT pin of power supply chip U1 exports through Zener diode D4 and inductance L1 Supply voltage.

Described single-chip microcomputer uses 16 single-chip microcomputers that Freescale company produces

MC9S12DP256B。

Described motor-drive circuit uses the motor drive ic MC33886 that Motorola Inc. produces, series electrical on it Current feedback circuit；Described current feedback circuit uses Hall-type current sensor TBC-5PS5, and its outfan is connected with single-chip microcomputer.

Described electromagnetic clutch drive circuit includes DDL-1.2 type electromagnetic clutch, NPN type triode S8050 and relay Device SRD-05VDC-SL-C, wherein, with electromagnetic clutch after NPN type triode S8050 and relay SRD-05VDC-SL-C series connection Device connects, and controls the folding of electromagnetic clutch, diode in parallel between relay coil two pins DCLH+ and PGND 1N4007, the base stage pin of NPN type triode S8050 is directly connected with the I/O mouth of single-chip microcomputer, by controlling I/O mouth height electricity Flat change controls the connecting and disconnecting of electromagnetic clutch.

Cmos voltage transducer LMC7660 chip that described sensor interface circuitry is produced by TI company and amplifier INA333 connects composition；LMC7660 provides the voltage of-5V for INA333, and the supply voltage making INA333 is+5V and-5V；Amplify Institute connecting resistance R3 between 1 pin and 8 pins of device INA333.

Described communication serial port circuit uses the MAX232 chip of TI company.

Described interface circuit includes 485 EBIs and CAN communication interface；The chip that 485 EBIs use is MAX485；CAN communication interface uses the TJA1050 chip of Freescale company.

Reserve A/D interface on described panel to be directly connected with the A/D passage pin of single-chip microcomputer.

This utility model, by gathering the signal of each early warning sensor, utilizes the logical judgment of singlechip controller to determine peace Full rank, and according to the difference of degree of danger, the control command under the different level of security of output, drive motor to control seat belt Coiler retracting number of times and the value of thrust of belt-strap, by the integrated mode that both are different, determine corresponding level of security, Guarantee human pilot is played and remind and the function of protection.

Have the advantages that

1, in terms of power supply, utilize car battery to provide power supply for whole control system, power-switching circuit will store The 12V voltage of battery is converted to the supply voltage needed for sensor, motor driving and electromagnetic clutch, single-chip microcomputer.

2, in terms of signal input, can each sensor signal of Real-time Collection, simultaneously by arranging corresponding sensor interface Circuit is for single-chip microcomputer identification.

3, in terms of signal processing logic computing, single-chip microcomputer it is uniformly controlled.

4, in terms of communication, using serial communication circuit, serial ports can control single chip computer and liquid crystal display screen show simultaneously.

5, in terms of driving, by single-chip microcomputer and corresponding peripheral drive circuit drive motor and the operating of electromagnetic clutch and Break-make.

6, in terms of feedback current, mainly by the electric current of armature and list is fed back to by current sensor Real-time Collection Sheet machine, the PWM wave voltage exported by regulation is regulated actual current size thus reaches the constant moment of force control to belt-strap System, electric current controls to use closed loop feedback and fuzzy PI hybrid control.

Accompanying drawing explanation

Fig. 1 is theory diagram of the present utility model；

Fig. 2 is this utility model power circuit principle figure；

Fig. 3 is BDM download circuit schematic diagram in this utility model；

Fig. 4 is motor-drive circuit schematic diagram in this utility model；

Fig. 5 is current feedback circuit schematic diagram in this utility model；

Fig. 6 is electromagnetic clutch drive circuit schematic diagram in this utility model；

Fig. 7 is sensor interface circuitry schematic diagram in this utility model；

Fig. 8 is key circuit schematic diagram in this utility model.

Detailed description of the invention

With embodiment, this utility model is described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1: a kind of active pretension seat belt controlling system, electricity is driven including power circuit, single-chip microcomputer, motor Road, electromagnetic clutch drive circuit, sensor interface circuitry, communication serial port circuit, BDM download circuit and interface circuit；Power supply Circuit is connected with single-chip microcomputer, motor-drive circuit, electromagnetic clutch drive circuit and sensor interface circuitry respectively, for whole master Dynamic formula pretension safety belt controller system provides applicable, stable power supply.Single-chip microcomputer is responsible for the process of signal and computing and exports Control signal, is the core of whole controller.Motor-drive circuit is used for driving motor to meet the retracting of actual belt-strap to be wanted Asking, current feedback circuit is used for the current signal of motor in real time armature and feeds back.Electromagnetic clutch drive circuit is used In the opening and closing of control electromagnetic clutch, connect, cut off power transmission.Sensor interface circuitry is for carrying out each sensor signal Process, facilitate single-chip microcomputer to receive and process.Communication serial port circuit, for convenient and microcontroller communication, receives and sends control letter Number.BDM download circuit is for controlling download and the on-line debugging of program.Interface circuit is connected with controller for all parts Connect, convenient extension.

As in figure 2 it is shown, described power circuit includes power supply input, power supply chip U1, described power supply inputs successively through power supply Switch S1, electric fuse F1, diode D1 and Zener diode connect the Vin+ pin of power supply chip U1, power supply chip U1's OUTPUT pin is through Zener diode D4 and inductance L1 output supply voltage；Due to for vehicle safety tape controller, so power supply Importation uses the input of accumulator 12V, and 12V power supply enters power supply chip U1, the work of D1 through electric fuse F1 and diode D1 With being to prevent user from power supply connecing the anti-hardware that damages, F1 is that circuit is shielded by the electric fuse of 3A, and power supply chip U1 is excellent Choosing uses LM2576 conversion chip, and the supply voltage of access can be converted to 5V, D4 is Zener diode, outside LM2576 Enclosing circuit ingredient, inductance L1 is the peripheral circuit building block of LM2576.Also connect between on and off switch S1 and electric fuse F1 It is connected to power supply indicator LED, preferably 12V power supply indicator.Described power circuit also include being connected to Zener diode D2 and Electric capacity C1, C2 between power supply chip U1, and the electric capacity C3 being connected with supply voltage outfan, electric capacity C1, C2, C3 play Voltage regulation filtering effect, it is ensured that the stability of 5V voltage output.

Single-chip microcomputer is the core of restraint system control system, assume responsibility for various sensor signal logical operations process and Send the responsibility of control signal control system normal operation.This utility model singlechip chip preferred Freescale company produces 16 single-chip microcomputers, model is MC9S12DP256B, and its minimum system is the minimal configuration system that can make normal circuit operation.It Minimum system include: reset circuit, clock circuit, debugging circuit for lamp and BDM download interface circuit.This utility model uses The standard clock circuit of MC9S12DP256, be for no reason at all external crystal-controlled oscillation of a 16MHz be connected on single-chip microcomputer EXTAL and On XTAL pin, utilize the phaselocked loop of MC9S12DP256 and voltage controlled oscillator can by this frequency upgrading to 24MHz, as The internal clocking bus of single-chip microcomputer.It is Low level effective that MC9S12 series monolithic resets, and reset circuit is multiple with single-chip microcomputer here Position pin is connected and uses the form of microswitch can realize electrification reset and manual key reset, facilitates circuit board function Debugging.Minimum system circuit adds debugging circuit for lamp, uses light emitting diode to be connected with single-chip processor i/o mouth, use single-chip microcomputer The level height controlling I/O mouth controls to debug the light on and off of lamp.Debugging circuit for lamp can make minimum system debugging convenient and verify electricity The fluency that road plate program burn writing success or not and chip run.

The special purpose interface that BDM download circuit is MC9S12DP256B program burn writing, wipes, control, debug, is the most general Time a kind of debugging interface, be widely used in various singlechip controller, as shown in Figure 3.

MC33886 has been internally integrated H-bridge circuit, and the voltage range of work is that 5V～40V meets safety belt controller work Voltage and motor driven voltage requirement, have the function of overload protection and error reporting.The effect of motor drive ic is by low Power, the pwm signal of low-voltage zoom into the high-power pwm signal of 24V, are controlled direct current generator, drive motor rotation. By the control to PWM ripple dutycycle, it is possible to achieve the rotating of motor and the regulation of velocity of rotation and the actual output of motor The size of moment of torsion, it is substantially to be controlled by armature sense of current and size.Meet intelligent prefastening Seat belt real work requirement, it is achieved seat belt drives rotating and the regulation of Motor torque of motor, it is thus possible to realize not With regulation to harness tension size under level of security.The motor that described motor-drive circuit is produced by Motorola Inc. Driving chip MC33886 and its peripheral circuit form, as shown in Figure 4.

Owing to control to approximate to the permanent moment of torsion of motor regards as by the constant current controlling of armature, therefore want Current of electric is carried out Real-time Collection, causes current direction to change it is also contemplated that motor steering is rotating, therefore current feedback Circuit is preferably the current sensor of Hall-type, and model is TBC-5PS5, and sample rate current is 5A, and sensor internal carries sampling electricity Resistance, chip output for voltage, directly and the ADC pin of single-chip microcomputer, current sensor is connected on motor and drives outfan 1 pin On galvanic electricity road.Current feedback circuit is as shown in Figure 5.

Electromagnetic clutch drive circuit transmits intermediary as the power of motor and Webbing retractor, wants when real work Ask and operate with motor simultaneously, i.e. connect electromagnetic clutch while electric machine rotation to drive coiler operating.The DDL-1.2 selected The rated voltage of type electromagnetic force clutch is 24V, and this utility model utilizes NPN type triode S8050 and relay SRD-05VDC- SL-C realizes on-off action, controls the folding of electromagnetic clutch.Because its magnetic induction coil switching meeting during electromagnetic clutch folding Produce inverse electromotive force, therefore diode 1N4007 in parallel between relay coil two pins DCLH+ and PGND, effectively Eliminate the inverse electromotive force impact on circuit, it is ensured that the reliable and stable operation of circuit.The base stage pin of S8050 is directly and monolithic The I/O mouth of machine is connected, and controls the connecting and disconnecting of electromagnetic clutch by controlling the change of I/O mouth low and high level, plays biography Pass and cut off the effect of motor power output, it is ensured that seat belt furling system can be properly functioning.Electromagnetic clutch drive circuit As shown in Figure 6.

Being usually analog quantity due to the amount of sensor output and numerical value is less, the effect of sensor interface circuitry is typically will Sensor acquisition to analog quantity be converted to the range of voltage values that single-chip microcomputer can identify.The voltage that MC9S12DP256AD gathers Scope is 0～5V, so each sensor signal to be amplified.

The maximum range of brake pedal force sensor is 670N, when 10V powers the range of signal of Full-span output be 0～ 20mv.Restriction due to power supply, it is considered to power brake pedal force sensor with 5V, now the range of signal of Full-span output is 0～10mv, in order to simplify calculating during A/D conversion, it is contemplated that the voltage amplification 500 of 10mv is reached 0～5V again.

What this utility model was selected is that the INA333 of TI company tentatively amplifies, and INA333 is that a kind of low-power consumption is accurate Instrument amplifier, has good accuracy.Can be by signal according to the value difference of institute connecting resistance R3 between 1 pin and 8 pins Amplifying 0～1000 times, by consulting chip PDF, when R3 is 200 Ω resistance, the amplification of chip is 500 times, full in theory Foot design requirement.Emulating with the carrying out of the simulation software TINA of TI company, input uses the voltage signal of 10mv, and reference resistance is The resistance of 200 Ω, meets the needs of the amplification 500 times of actual requirement.

But during circuit board hardware test is debugged, find this actual times magnification of single scaling circuit Number can not meet far away the amplification requirement of 500 times, through investigation and further test, has selected and has been all what TI company produced LMC7660 chip uses with INA333 simultaneously.LMC7660 is a cmos voltage transducer, it is possible to by the positive electricity of 10V～1.5V Pressure is converted to the negative voltage of-1.5V～-10V, in operating temperature and voltage range, it is not necessary to external diode, has low static state The feature of electric current high-conversion rate.The effect of LMC7660 mainly provides the voltage of-5V for INA333, make in INA333 7 pins and Voltage between 4 pins is respectively+5V and-5V, now the voltage reference of chip be the supply voltage of 0V, i.e. INA333 be+5V With-5V, farthest reducing the bias impact on INA333, actual measurement meets the requirement amplifying 500 times, circuit theory Figure is as shown in Figure 7.

This utility model uses serial communication to realize the communication of safety belt controller and host computer.Communication serial port circuit uses Be the MAX232 chip of TI company, MAX232 running voltage is 5V, and effect is to realize single-chip microcomputer Transistor-Transistor Logic level and computer 232 Between level conversion thus reach the purpose with upper machine communication, interface uses BD9 interface.Serial ports is utilized on host computer Assistant, by directly completing related command by control single chip computer with the connection of 232 interfaces, it is achieved that upper computer software emulation Function.

Multiple interfaces circuit is to meet controller and each peripheral components consolidates the parts of connection, and interface of the present utility model has Driving interface, the driving interface of clutch, ultrasonic sensor interface, brake pedal force sensor interface, the liquid crystal display screen of motor External interface, various interfaces determine encapsulation and type all in accordance with pcb board size.Data transmit-receive pin due to MC9S12DP256 Limited, so have employed the mode connected by method selection 232 or 485 bus of jump cap short circuit, switching ultrasonic sensor and Liquid crystal display screen show state accordingly.

For meet controller debugging and with each interface, the compatibility of bus, this utility model is when board design Reserve 485 EBIs and CAN communication interface, facilitate debugging and the real train test in later stage.RS485 bus is a kind of normal The serial bus standard seen, uses balance to send the mode accepted with difference, therefore has the ability of suppression common mode disturbances, actual Communication distance can reach about 3000 meters, also has a wide range of applications in the work system of multinode.485 bus communications use Chip be MAX485, primarily serve Transistor-Transistor Logic level and the transduction of 485 protocol requirement level.

Increasing and information transfer rate required more and more higher along with Hyundai Motor electronic control system and communication system, Automobile CAN-bus has been widely applied in the middle of Hyundai Motor electronic control system at present.CAN is as a kind of on-the-spot total In the shared bus that line energy is real-time, the information data of each node realizes synchronous transfer, solves the wiring of orthodox car electric-control system multiple Miscellaneous take a large amount of interior space, the problem that speed is slow, be not easy to maintenance is shared in information transmission.On communication speed, CAN is made For high-speed bus, the maximum speed of communication can reach 1MB/s, substantially increases the communication speed of data and information, it is achieved that each The Real-Time Sharing of nodal information.In order to meet the extension needs of multiplex roles, the active pretension seat belt of this utility model design 2 CAN data-interfaces reserved by controller, use the TJA1050 chip of Freescale company, and the 1 of chip, 4 draw Foot is connected with the CAN communication passage pin on single-chip microcomputer respectively.

In terms of the selection of early warning sensor, this utility model has only selected pressure transducer and ultrasonic sensor sensing Device.But intelligent driving safety system is it is desirable that gather the signal of various sensor, carries out comprehensive logic and sentence in ECU Break to provide and ensure best security performance.On the controller board of this utility model design, spy has reserved A/D interface, directly with The A/D passage pin of single-chip microcomputer is connected, and adds multiple sensor signal when facilitating subsequent development to design.

The active pretension seat belt of this utility model design determines three level of securitys, in difference on control strategy Level of security under, single-chip microcomputer sends different control signal and drives motor to complete corresponding action.When reality controls, use Host computer serial communication controls, liquid crystal display screen touch control, and software flow controls, and hardware button Non-follow control various control side Method, convenient observation and experiment, therefore add key circuit when controller designs, facilitate manual simulation hardware and debugging.As Shown in Fig. 8.

Embodiment described above only have expressed embodiment of the present utility model, and it describes more concrete and detailed, but also Therefore the restriction to this utility model the scope of the claims can not be interpreted as, as long as using equivalent or the form institute of equivalent transformation The technical scheme obtained, all should fall within protection domain of the present utility model.

Claims (9)

1. an active pretension seat belt controlling system, it is characterised in that panel includes power circuit, single-chip microcomputer, motor Drive circuit, electromagnetic clutch drive circuit, sensor interface circuitry, communication serial port circuit, BDM download circuit and interface electricity Road；Described power circuit is respectively with single-chip microcomputer, motor-drive circuit, electromagnetic clutch drive circuit and sensor interface circuitry even Connect；Described single-chip microcomputer and BDM download circuit are bi-directionally connected and communication serial port circuit and interface circuit both-way communication, single-chip microcomputer Output port connects motor-drive circuit and electromagnetic clutch drive circuit, and the input port of single-chip microcomputer is by sensor interface electricity Road receives the output signal of various sensors.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: described power circuit includes Power supply input and power supply chip U1；The input of described power supply connects the Vin+ of power supply chip U1 successively through electric fuse F1 and diode D1 Pin, the OUTPUT pin of power supply chip U1 is through Zener diode D4 and inductance L1 output supply voltage.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: described single-chip microcomputer uses and flies Think 16 single-chip microcomputer MC9S12DP256B that karr company produces.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: described motor-drive circuit Use the motor drive ic MC33886 that Motorola Inc. produces, series current feedback circuit on it；Described current feedback electricity Road uses Hall-type current sensor TBC-5PS5, and its outfan is connected with single-chip microcomputer.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: described electromagnetic clutch drives Galvanic electricity road includes DDL-1.2 type electromagnetic clutch, NPN type triode S8050 and relay SRD-05VDC-SL-C, wherein, NPN It is connected with electromagnetic clutch after type audion S8050 and relay SRD-05VDC-SL-C series connection, controls opening of electromagnetic clutch Close, diode 1N4007 in parallel, the base stage of NPN type triode S8050 between relay coil two pins DCLH+ and PGND Pin is directly connected with the I/O mouth of single-chip microcomputer, controls the connection of electromagnetic clutch by controlling the change of I/O mouth low and high level With disconnection.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: described sensor interface electricity The cmos voltage transducer LMC7660 chip that route TI company produces is connected composition with amplifier INA333；LMC7660 is INA333 provides the voltage of-5V, and the supply voltage making INA333 is+5V and-5V；1 pin of amplifier INA333 and 8 pins it Between institute connecting resistance R3.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: described communication serial port circuit Use the MAX232 chip of TI company.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: described interface circuit includes 485 EBIs and CAN communication interface；The chip that 485 EBIs use is MAX485；CAN communication interface is adopted Be the TJA1050 chip of Freescale company.

Active pretension seat belt controlling system the most according to claim 1, it is characterised in that: reserved on described panel A/D interface is directly connected with the A/D passage pin of single-chip microcomputer.