Four-axle aircraft does not have the implementation that brushs dc machine drive to control a design
- source:GAENOR CNC Machining
In drive circuit, q1~Q3 uses the) of IRFR5305(P raceway groove of IR company, q4~Q6 is) of IRFR1205(N raceway groove. Diode of follow on current hides inside this effect canal, voltaic access is provided when for field effect the canal closes, in order to prevent the retrorse breakdown of pipe, parameter of its model character sees a table 1.
T1~T3 uses PDTC143ET to provide drive signal for field effect canal. Express 1 MOSFET to be in charge of parameter by the graph 1 knowable, a1~A3 provides signal of drive of grid of arm of the bridge on three-phase complete bridge, as odd as ATMEGA16 the signal of hardware PWM drive of a machine is conterminous, pass those who change PWM signal to occupy empty Bilaishi to show electric machinery rotate speed to control;B1~B3 to provide signal of drive of grid of arm playing the bridge, by sheet piece the I/O mouth of machine is offerred directly, have guide with end two kinds of condition. Graph 1 without brush dc machine three-phase circuit of drive of 6 arms complete bridge is not had brush control of dc machine drive to use three-phase 6 state control is politic, power canal has 6 kinds to spark condition, every time only two pipe guide, inverting of angle of report of every 60 ° , when if some engraves AB photograph to guide temporarily,be being connected, c photograph up to, without voltaic output. Odd a position of electric machinery rotor that machine basis detects, the switch that uses MOSFET is characteristic, realize the electrify of electric machinery to control, for example, when Q1, Q5 is opened, AB photograph guides, right now voltaic flow direction is negative pole of power source of → of Q5 of → of B of winding of → of A of winding of → of Q1 of → of power source anode. Similar, open order to be Q1Q5 respectively when MOSFET, q1Q6, q2Q6, q2Q4, q3Q4, when Q3Q5, want to undertake accurate inverting in equal opportunity only, can come true to run continuously without what brush dc machine. 2 turn over electromotive force to pass 0 detect without brush dc function to run continuously normally quite, be about to undertake detecting to rotor position, realize accurate inverting thereby. Position of electric machinery rotor detects means basically has photoelectricity to code dish, Huo Er sensor, without feeling measure 3 kinds of way.
Because four-axle aircraft is not had,brush dc confidential to demand construction of system simple, weight is light, use the means that does not have positional sensor consequently, the n/ele be induced by electromotive force that uses three-phase generation passes at 0 o'clock hour defer 30 ° inverting. Although this method compares a trouble when electric machinery is started, can accuse sexual difference, but as a result of circuit simple, cost is low, agree with not to need the four-axle aircraft electric machinery that starts often in normal flight process consequently. Because do not have the two-phase that brushs dc machine to guide,know pattern, can use consequently do not guide the three-phase that connect detects the size that opposes electromotive force. If pursue 2 turn over electromotive force to detect circuit, neutral site N and odd an AIN0 of machine is conterminous, ain, bin, cin accepts the order respectively the ADC0 of a machine, ADC1, ADC2.
Keep comparing neuter to nod N voltage and A, b, c three-phase the size of voltage of 3 end points, give every n/ele be induced by electromotive force in order to detect over- at 0 o'clock. ATMEGA16 is odd of a machine imitate comparator be AIN0 to input end, lose to the input end configuration according to ADMUX register choice ADC0, ADC1, ADC2, used sheet thereby piece machine of the imitate comparator that takes oneself answer with the function. When A, during B photograph electrify, c contrary electromotive force and neutral site N undertake comparative, similar, can detect successfully give each look cross 0 incident. Graph 2 turn over electromotive force to detect of circuit electric machinery turn over electromotive force to detect after coming out, can find those who oppose electromotive force to pass at 0 o'clock, in turn over electromotive force to pass 0 hind angle of 30 ° report has delay inverting operation. 3 control programming 3.
Self check of electrify of circuit of 1 drive control is not had brush dc machine drive to control a part to include MOSFET self check, electric machinery to start control and voltage electric current to monitor a function 3 parts. The flow of electrify self check of drive control circuit is shown 3 times like the graph, include MOSFET short circuit character and guide a characteristic test, shed attaint circuit in order to had prevented. Graph flow chart of self check of electrify of circuit of 3 drive control 3.
2 software start control to turn over electromotive force to detect the law is in only the ability after electric machinery runs normally undertakes, do not turn when electric machinery or when rotate speed is very low, its turn over electromotive force to cannot detect, use the means that software starts consequently. In the light of control without what brush dc machine without positional sensor, the article uses the method that 3 paces start, above all, give A, b photograph electrify period of time in order to secure; of position of electric machinery rotor 6 condition by turns inverting, weld time reduces; to detect stage by stage of three-phase oppose electromotive force, if start a success normally, start afresh otherwise. The specific flow that start is shown 4 times like the graph. Graph 4 without brush start technological process without feeling dc electric machinery 3.
Function of aero system protection includes four-axle of design of function of 3 systems protection voltage, electric current monitors a function. Batteries voltage monitors functional circuit: Press voltage drop of circuit general batteries to sheet through simple cent piece inside the input range that machine A/D changeover permits (0~5 V) , monitor the electric machinery when preventing voltage to be not worth to stop through voltage turn; electric current detects functional circuit: Through 0.
Electric current of sampling of resistor of 01 Ω , translate into voltage, send sheet piece the A/D of machine changes a mouth, when malfunctioning in order to prevent, big electric current damages circuit. When electric current is monitored, use means of simple wave of numeric and average filter, the influence of electric current of abate instantaneous peak value to measuring an outcome. The article realizes 4 epilogue aero dc does not have four-axle the drive circuit that brushs electric machinery and programming of systematic control software. Drive circuit uses three-phase circuit of 6 arms complete bridge, MOSFET regards switch as component, use ATmega 16 sheet piece machine regard control as chip, turn over electromotive force to pass 0 detect and the control way that software starts, and 30 ° have delay inverting. After be being started normally, odd implementation does not have a machine output PWM brush dc engine rotate speed to adjust. Designed voltage, electric current to monitor circuit at the same time, make sure the system is safe, consequently, this system can normal drive is not had without positional sensor brush dc machine, and can apply at four-axle aircraft. CNC Milling CNC Machining