CN204506581U

CN204506581U - A kind of controller of current vortex retarder

Info

Publication number: CN204506581U
Application number: CN201520163106.3U
Authority: CN
Inventors: 王维斌; 吴成加
Original assignee: HEFEI SHINNY INSTRUMENT CONTROL TECHNOLOGY Co Ltd
Current assignee: HEFEI SHINNY INSTRUMENT CONTROL TECHNOLOGY Co Ltd
Priority date: 2015-03-17
Filing date: 2015-03-17
Publication date: 2015-07-29
Anticipated expiration: 2025-03-17

Abstract

The utility model discloses a kind of controller of current vortex retarder and control method thereof; described controller comprises micro controller system and is connected to the signal input module of micro controller system, indicator lamp, CAN communication interface, driving circuit and current sampling circuit; wherein the IGBT module of driving circuit is connected to micro controller system by AND circuit U3, and current sampling circuit comprises sampling resistor R3, retarder coil assembly L, current foldback circuit U4 and sampled signal modulate circuit U5.Described current vortex retarder can by gathering the information such as engine speed, throttle opening, the speed of a motor vehicle and temperature, judge current car load situation and braking requirement amount etc., regulate IGBT module output duty cycle voluntarily, the electric current flowing through retarder coil is changed, to produce different braking forces, realize service brake; When detecting that retarder temperature is too high, controller reduces horsepower output automatically, ensure that the work safety of brake system, improves the reliability of car brakeing, has ensured traffic safety.

Description

A kind of controller of current vortex retarder

Technical field

The present invention relates to technical field of automobile control, be specially a kind of controller of current vortex retarder and control method thereof.

Background technology

At present, the service brake of full size vehicle, current vortex retarder is generally adopted to improve vehicle braking force in the process of moving, eddy current retarder is divided into two parts, control circuit and actuating unit, actuating unit is the mechanical assembly of one group of excitation coil and corresponding physical construction composition, and control circuit passes into electric current by the excitation coil to actuating unit, at the corresponding braking force of the upper generation of rotating shaft (transmission shaft) of actuating unit, braking is performed to vehicle.Traditional controller of current vortex retarder generally adopts stepping formula mode, as shown in Figure 1, according to the change of cabinet switch (hand braking or foot brake signal), in batches power supply is switched on or switched off to many group excitation coil L1, L2, L3, L4, regulates service brake power; Switching valve generally adopts the BTS550 power device of company of Infineon, in the moment of switching valve conducting, because rush current is larger, make the current changing rate flowing through power device when braking larger, be unfavorable for the long-time use of power drive device, after power device is energized for a long time, controller internal operating temperature raises, affect product service life, and cannot adjust according to the braking force of load change to current vortex retarder in use procedure, when vehicle underloading and zero load, result of use is poor, reduces the stability of service brake.

Patent name is: refer to by microprocessor Real-time Collection vehicle speed signal, temperature of rotor signal in the control method of eddy current retarder braking moment and driving governor [patent No.: ZL201010146019.9], when temperature is normal, microprocessor is the pwm control signal of definite value according to current gear output duty cycle, carries out opened loop control to eddy current retarder braking moment; When temperature over-range, closed loop control carried out by microprocessor, and being controlled by temperature of rotor near threshold temperature, is open loop or closed loop control limit value with temperature limit in the method, and in multiple-rank control, add PWM control, and Multistage stepping add PWM control after, its produce lock torque less, system temperature influence is larger, when after vehicle heavy load, electric braking can not prior involvement, and can produce braking force not foot phenomenon, braking effect is poor.

Adopt similar control scheme, patent name is: refer to controller after brake pedal is operated in associated braking system controller of current vortex retarder and control method [patent No.: ZL201010590330.2], according to pwm control signal, pedal position, car speed change, calculate the real-time braking force of automobile, then the gradient residing for automobile is calculated, table look-up again and obtain braking force ratio, retarder magnet coil is applied to the pwm control signal of corresponding dutycycle, realize auxiliary braking.After the program is inputted by coherent signal, calculate the real-time braking force of automobile, and then braking force is applied to brake system, in actual application, running car braking force, not only relevant with the speed of a motor vehicle, also with running car category of roads, road traffic condition (hill path, at a high speed, rain, snow), the load condition of automobile is (unloaded, heavy duty) etc. factor be correlated with, because automobile is at level road, climbing, braking force required in the acceleration of descending or braking procedure is different, the practical application effect of the program can because of calculation of parameter deviation, its braking effect exported can be subject to obvious impact.

Summary of the invention

For overcoming above-mentioned deficiency, the invention provides that a kind of structure is simple, the controller of current vortex retarder of dependable performance and control method thereof, by gathering the information such as engine speed, throttle opening, the speed of a motor vehicle and temperature, judge that current car load situation and braking requirement amount carry out exporting the controller of current vortex retarder controlled.

Technical scheme of the present invention is as follows: a kind of controller of current vortex retarder, comprise micro controller system and the signal input module, indicator lamp, the CAN communication interface that are connected to micro controller system, it is characterized in that: described controller also comprises driving circuit and current sampling circuit, described driving circuit comprises AND circuit U3 and IGBT module, and described AND circuit U3 is connected with micro controller system; Described current sampling circuit comprises sampling resistor R3, retarder coil assembly L, current foldback circuit U4 and sampled signal modulate circuit U5; Described retarder coil assembly L is connected with the IGBT module mouth of driving circuit; Described retarder coil assembly L is also connected with current foldback circuit U4 with sampling resistor R3; Described current foldback circuit U4 is connected with current sampling circuit U5, and is connected with micro controller system respectively.

Preferably, described CAN communication interface is connected with vehicle body driving engine CAN network.

Preferably, described signal input module comprises: brake voltage sample circuit, brake switch, speed sensor and temperature sensor, described brake voltage sample circuit is connected with brake pedal, described brake switch is connected with braking pressure loop, and described speed sensor and temperature sensor are connected with retarder stator coil respectively.

Preferably, described retarder coil assembly L is composed in parallel by 4 groups of retarder coils (L1, L2, L3, L4), and described one end of retarder coil assembly L is connected with the mouth of IGBT module, and the other end is connected with the ungrounded end of sampling resistor R3.

Preferably, the input end 31 that described current foldback circuit comprises voltage comparator U4 and input AND circuit U3, AND circuit U3 is connected with the control output end of micro controller system, and another input end 32 of AND circuit U3 is connected with the mouth of voltage comparator.

Preferably, described IGBT module is connected with the gate pole of IGBT module Q3 with driving aerotron Q1, Q2, driving resistance R1 by input protection circuit.

Preferably, described input protection circuit is in parallel by resistance R2 and bi-directional voltage suppressing unit D, then is composed in series with the resistance R1 of IGBT module.

Preferably, described indicator lamp is light beam or striation display.

A control method for controller of current vortex retarder, comprises the following steps:

(1) in vehicle travel process, micro controller system passes to the vehicle speed signal of micro controller system by the relevant information such as rotating speed, throttle opening of CAN communication interface driving engine and speed sensor, judges current car load state; And according to the characteristic of underloading, normal, heavy duty three kinds of different conditions, generate No. PWM that an output frequency is fixed, dutycycle is adjustable by the control slope of correspondence, as output controlling quantity;

(2) micro controller system export No. PWM, the gate pole of IGBT module Q3 is loaded into by AND circuit U3, IGBT module is made to export a PWM voltage, when IGBT module Q3 exports PWM voltage signal, because 4 maps of current vortex retarder coil are connected in parallel, this voltage is loaded on 4 maps of retarder simultaneously, and micro controller system is by changing the output duty cycle of pwm signal, realize the Current adjustment to this 4 map, thus regulate the braking force that retarder produces;

(3) when having electric current to input in retarder coil, its electric current is through sampling resistor, and a voltage is produced on sampling resistor, this voltage signal is input to current sampling circuit and current foldback circuit simultaneously, micro controller system reads sampled voltage, and in conjunction with the current temperature signal collected, timely adjustment output duty cycle;

(4) when microprocessor detect is too high to retarder temperature, buffer controller can reduce the dutycycle of output pwm signal automatically, reduces the horsepower output of current vortex retarder; When retarder coil generation over-current phenomenon avoidance; the electric current flowing through sampling resistor increases; voltage also increases thereupon; after sampled voltage is increased to the protection value of setting; current foldback circuit exports a guard signal, directly turns off the input end of driving circuit, IGBT module is exported and closes; prevent IGBT module from damaging because of overcurrent, protect the safety of system.

Beneficial effect of the present invention: by gathering the information such as engine speed, throttle opening, the speed of a motor vehicle and temperature, judge current car load situation and braking requirement amount etc., regulate IGBT module output duty cycle voluntarily, the electric current flowing through retarder coil is changed, to produce different braking forces, realize service brake; When detecting that retarder temperature is too high, controller reduces output braking force automatically, improves the reliability of car brakeing, guarantee driving safety.

Accompanying drawing explanation

Fig. 1 is the multiple-rank control schematic diagram in prior art.

Fig. 2 is the structure composition schematic diagram in the technical program.

Fig. 3 is the electrical block diagram in the technical program.

Fig. 4 is different control slope curve.

Fig. 5 is output duty cycle.

In accompanying drawing: 1, signal input module; 2, indicator lamp; 3, CAN communication interface; 4, driving circuit; 5, current sampling circuit; 11, brake switch; 12, brake voltage sample circuit; 13, speed sensor; 14, temperature sensor;

U3, AND circuit; U4, current foldback circuit; U5, current sampling circuit; D, bi-directional voltage suppressing unit

R2, resistance; R3, sampling resistor; L1-L4 retarder coil; L retarder coil assembly;

The input end of 31-32, AND circuit U3; The mouth of 33 AND circuit U3

Detailed description of the invention

Below in conjunction with accompanying drawing, the present invention will be further described.

As shown in Figures 2 and 3, a kind of controller of current vortex retarder, comprises micro controller system and is connected to the signal input module 1 of micro controller system, indicator lamp 2, CAN communication interface 3, driving circuit 4 and current sampling circuit 5.

Wherein signal input module 1 comprises: brake voltage sample circuit 11, brake switch 12, speed sensor 13 and temperature sensor 14, described brake voltage sample circuit 11 is connected with brake pedal, described brake switch 12 is connected with braking pressure loop, and described speed sensor 13 is connected with retarder stator coil respectively with temperature sensor 14; Indicator lamp 2 is light beam or striation display, and its variation range lighted is corresponding with the output duty cycle of PWM ripple; One end of CAN communication interface 3 is connected with chip microcontroller interactive signal, and the other end is connected with vehicle body driving engine CAN network; Driving circuit 4 comprises AND circuit U3 and IGBT module Q3; AND circuit U3 is connected with micro controller system; the gate pole of AND circuit U3 mouth by driving aerotron Q1, Q2 and driving resistance R1 to be connected to IGBT module Q3; resistance R2 and bi-directional voltage suppressing unit D is in parallel; the gate pole input protection circuit of IGBT module is composed in series again with R1; the mouth of IGBT module is connected with retarder coil assembly L, and retarder coil assembly L is connected with current foldback circuit U4, sampled signal modulate circuit U5 with sampling resistor R3.Wherein retarder coil assembly L is composed in parallel by 4 groups of retarder coils (L1, L2, L3, L4), and described one end of retarder coil assembly L is connected with the mouth of IGBT module, and the other end is connected with the ungrounded end of sampling resistor R3; Current sampling circuit 5 comprises sampling resistor R3, retarder coil assembly L, current foldback circuit U4 and sampled signal modulate circuit U5; Described current foldback circuit U4 is connected with AND circuit U3, current sampling circuit U5, and is connected with micro controller system respectively.

As shown in Figure 3, brake voltage signal is the signal exported by vehicle brake pedal, when chaufeur steps on brake pedal, steps on angle along with pedal, has corresponding change of voltage.Its voltage change range is 0 ~ 5V, and effective identification range is 0.5 ~ 4.5V, and this voltage is sampled by the brake voltage sample circuit 11 that micro controller system connects;

After chaufeur steps on brake pedal, the braking gas circuit of vehicle is switched on, along with the increase gradually of air pressure, S1, S2 in gas brake switch 12 are successively switched on, and this signal is gathered by micro controller system simultaneously, in vehicle travel process, retarder rotor High Rotation Speed on transmission shaft, is installed on the speed sensor on retarder stator coil, senses the change of transmission shaft rotor, produce vehicle speed pulse, gathered by micro controller system.When vehicle operation, Engine ECU can by current engine speed, the information such as throttle opening are delivered in CAN, this information is received by CAN communication interface by micro controller system, micro controller system comprehensively analyzes the relation of engine speed and the speed of a motor vehicle under each throttle opening current (throttle value), judge the load condition that vehicle is current, engine speed under rated load operating mode can produce corresponding vehicle speed signal and export, its throttle opening (Das Gaspedal value) also has corresponding change, when under a certain speed of a motor vehicle, throttle opening is compared with comparatively large under standard duty or when having significant change, show that vehicle is in heavy lift state, otherwise be then light condition.After micro controller system collects brake voltage signal and brake switch signal, can adopt according to the current load condition identified and control slope curve accordingly.

As shown in Figure 4, in figure, B curve is the controlling curve of normally loaded condition, in the figure, the longitudinal axis is the output valve of brake pedal, when the initial stage that brake pedal is stepped on, because the dead zone voltage of pedal exists, PWM controller does not export, in order to better realize controlling, be about 0.9V by dead band voltage identification, only have when brake pedal steps on certain altitude, when pedal output voltage is greater than 0.9V, controller just can according to speed-slackening signal, on-off signal, vehicle speed signal etc. make corresponding output, the maximum effective value of brake pedal is 4.5V, transverse axis is the output duty cycle (braking force) under this brake voltage, maxim is 100%, be about 1800 ~ 2300N/M.As shown in Figure 5, under normally loaded condition, during vehicle is advanced, when the voltage of brake pedal is about 1.5V, controller exports the PWM ripple of about 25%, is equivalent to the braking force obtaining 1/4th, when the voltage of brake pedal is about 4.5V, controller exports the PWM ripple of 100%, is equivalent to obtain maximum braking force and exports.In Fig. 4, C curve is controlling curve under case of heavy load, can be found out by this curve, in heavy lift travels, when the voltage of brake pedal is about 3V, controller has exported the PWM ripple of 100%, make electric braking prior involvement, realizing gently stops can reach good effect of braking, and in figure, A curve is controlling curve in underloading situation, can be found out by this curve, in underload travels, when the voltage of brake pedal reaches maxim, controller exports the PWM ripple of about 75%, makes the delayed intervention of electric braking, ensure that when vehicle underloading, braking force exports lower.

In Fig. 3, PWM drive circuit is by AND circuit U3, drive aerotron Q1, Q2, drive resistance R1, resistance R2, bi-directional voltage suppressing unit D forms, wherein drive resistance R1, resistance R2, bi-directional voltage suppressing unit D is the input protection circuit of IGBT module Q3, prevent from causing malfunction or IGBT module Q3 to damage because driving circuit controls fault or interference etc., the PWM ripple that micro controller system exports, pass through and AND circuit U3, drive aerotron Q1, Q2, resistance R1 is driven to be loaded into the gate pole of IGBT module Q3, Q3 is made to be operated on off state, retarder 4 groups of coils from parallel connection of coils are to the output port of IGBT module, during IGBT module work, 4 groups of coil (L1, L2, L3, L4) electric current is all had to flow through, produce Induced magnetic field, and form application force (lock torque), the size of application force is decided by the output duty cycle of IGBT module, as shown in Figure 5, in figure, show respectively the PWM waveform of different duty, this control waveform is for controlling the on off state of IGBT module, when output PWM dutycycle is 100%, IGBT module is equivalent to entirely export retarder 4 groups of coils, when output is 50% dutycycle, is equivalent to carry out half output to retarder 4 groups of coils.When IGBT module works, the change of its PWM ripple dutycycle, can show with the form of indicator lamp signal simultaneously, indicator light circuit is made up of a string Column being luminous or light-emitting section, and its variation range lighted is corresponding with the output duty cycle of PWM ripple, when retarder works, micro controller system exports control signal, to light corresponding light beam or striation to show the output state of current retarder, when IGBT module exports entirely, striation or light beam are all lighted.When PWM exports stopping, striation all extinguishes.In Fig. 3, sampled signal modulate circuit U5 is made up of a voltage follower, when R3 there being voltage produce, this voltage is amplified by 1: 1, and be sent to the voltage sample input end of micro controller system, current foldback circuit U4 is made up of a voltage comparator, when the voltage signal of generation on R3, this voltage is fed to the reverse input end of comparator, the in-phase input end of comparator is a fixed voltage source Vref, by the comparative voltage Vref of adjustment U4 in-phase input end, protection current value can be set, namely the maximum current flowing through retarder coil is regulated, R3 in Fig. 3 is current sampling resistor, when there being electric current to flow through retarder coil and sampling resistor R3, sampling resistor R3 produces a voltage, this voltage is sent to the ADC sampling input port of CPU by sampled signal modulate circuit U5, Real-Time Monitoring is carried out to sample rate current, this voltage is also sent into current foldback circuit U4 simultaneously and is compared, rise when causing electric current for some reason, sampled voltage is made to increase, the reverse input end voltage rise of voltage comparator U4, when this voltage exceedes the value of comparator in-phase input end voltage Vref, comparator U4 exports a low level, this level signal is sent to the acquisition of signal port of input end 2 with door U3 and micro controller system simultaneously, the output of AND circuit U3 turns off, pwm signal no-output, IGBT module Q3 quits work, IGBT module is avoided to damage because of overcurrent, simultaneously, microprocessor detect is to over-current signal, can process accordingly.

In vehicle travel process, owing to braking continuously or other reason, when causing retarder temperature to rise, microprocessor detect is to this temperature signal, when temperature rises to setting value, system enters falls power mode output, now, micro controller system can according to the current speed of a motor vehicle, load condition, the parameters such as retarder temperature, reduce the PWM dutycycle exported automatically, make its outgoing current step-down, ensure that current vortex retarder is operated within the scope of a safe and reasonable.

The control method of controller of current vortex retarder, comprises the following steps:

1, in vehicle travel process, micro controller system passes to the vehicle speed signal of micro controller system by the relevant information such as rotating speed, throttle opening of CAN communication interface driving engine and speed sensor, judge current car load state, be identified as underloading, normal, heavy duty three kinds of states, and according to the characteristic of often kind of state, by adopting different control slopes, regulation output electric current is carried out with different pwm signals, avoid the phenomenon that underloading heavy brake or heavy duty are gently stopped, achieve automatic load regulable control.

2, in conventional solution, owing to using BTS550 power device as switch control rule, the moment of switching valve conducting, rush current is comparatively large, and make the current changing rate flowing through power device when braking comparatively large, temperature rise is very fast, when after vehicle heavy load, electric braking can not prior involvement, and can produce braking force not foot phenomenon, braking effect is poor.

3, when IGBT module is as switching valve, export owing to adopting PWM mode, at the conducting initial stage, by its output duty cycle of software adjustment, curent change is slowly increased, improvement system affects the rush of current of retarder, simultaneously, because retarder 4 groups of excitation coils are with entering incircuit, the magnetic field produced is comparatively balanced, when vehicle underloading, passing into less electric current can braking force needed for postpartum, with the braking deviation only accessing a group or two groups of coils in stepping formula control program and produce, its controller characteristic curve is more stable, and gear shift is rapid, can realize from zero to the output of maximum braking force by changing PWM output duty cycle.

4, controller is provided with automated closed-loop control, the operating temperature of real-time detection retarder, after controller detects that internal operating temperature rises to warning value, or when instantaneous overcurrent phenomenon having been detected, automatically output duty cycle can be reduced, outgoing current is reduced, ensure that brake system is operated within safe scope.

Although give detailed description and explanation to the specific embodiment of the present invention above; but what should indicate is; we can carry out various equivalence according to conception of the present invention to above-mentioned embodiment and change and amendment; its function produced do not exceed that Figure of description contains yet spiritual time, all should within protection scope of the present invention.

Claims

1. a controller of current vortex retarder, comprise micro controller system and the signal input module (1), indicator lamp (2), the CAN communication interface (3) that are connected to micro controller system, it is characterized in that: described controller also comprises driving circuit (4) and current sampling circuit (5), described driving circuit (4) comprises AND circuit U3 and IGBT module, and described AND circuit U3 is connected with micro controller system; Described current sampling circuit (5) comprises sampling resistor R3, retarder coil assembly L, current foldback circuit U4 and sampled signal modulate circuit U5; Described retarder coil assembly L is connected with the IGBT module mouth of driving circuit (4); Described retarder coil assembly L is also connected with current foldback circuit U4 with sampling resistor R3; Described current foldback circuit U4 is connected with current sampling circuit U5, and is connected with micro controller system respectively.

2. controller of current vortex retarder according to claim 1, is characterized in that: described CAN communication interface is connected with micro controller system, and CAN communication interface is also connected with vehicle body driving engine CAN network.

3. controller of current vortex retarder according to claim 1, it is characterized in that: described signal input module (1) comprising: brake voltage sample circuit (11), brake switch (12), speed sensor (13) and temperature sensor (14), described brake voltage sample circuit (11) is connected with brake pedal, described brake switch (12) is connected with braking pressure loop, and described speed sensor (13) is connected with retarder stator coil respectively with temperature sensor (14).

4. controller of current vortex retarder according to claim 1, it is characterized in that: described retarder coil assembly L is composed in parallel by 4 groups of retarder coils (L1, L2, L3, L4), described one end of retarder coil assembly L is connected with the mouth of IGBT module, and the other end is connected with the ungrounded end of sampling resistor R3.

5. controller of current vortex retarder according to claim 1; it is characterized in that: described current foldback circuit comprises voltage comparator U4 and input AND circuit U3; the input end 31 of AND circuit U3 is connected with the control output end of micro controller system, and another input end 32 of AND circuit U3 is connected with the mouth of voltage comparator.

6. controller of current vortex retarder according to claim 1, is characterized in that: described IGBT module is connected with the gate pole of IGBT module Q3 with driving aerotron Q1, Q2, driving resistance R1 by input protection circuit.

7. controller of current vortex retarder according to claim 6, is characterized in that: described input protection circuit is in parallel by resistance R2 and bi-directional voltage suppressing unit D, then is composed in series with the driving resistance R1 of IGBT module.

8. controller of current vortex retarder according to claim 1, is characterized in that: described indicator lamp is light beam or striation display.

9. a control method for controller of current vortex retarder, is characterized in that: comprise the following steps: