CN101739013B - Digital control system for satellite aerial directing mechanism - Google Patents

Abstract

The invention discloses a digital control system for a satellite aerial directing mechanism which is applied to driving and controlling a novel high-precision reliable satellite aerial directing mechanism. The system comprises a digital signal processor (DSP), a synchronous machine, a rotary transformer, a Hall effect rotor position sensor, an exciting output circuit, an axial angle decoder circuit, a three-phase bridge type power module, a PWM driving circuit, a three-phase winding current detecting circuit, a communication module circuit, a secondary power supply transfer circuit, and a protection circuit. The system can realize the high-precision control for the satellite aerial directing mechanism by the upper computer communication, the output shaft position detection, the winding current detection, the motor rotor position detection and a series of control methods.

Description

A kind of digital control system for satellite aerial directing mechanism

Technical field

The present invention relates to a kind of digital control system for satellite aerial directing mechanism, this system has the advantage of high integration, small size, low-power consumption, high reliability, is applicable to satellite antenna high precision sensing control.

Background technology

Directing mechanism is the movement executing mechanism of satellite antenna, occupies an important position in whole star system.Along with the development of Chinese large-sized telstar, repeater satellite technology, had higher requirement in precision, life-span, the reliability aspect of digital control system for satellite aerial directing mechanism at present.Therefore, a kind of directing mechanism digital control system with high precision, high integration, high reliability of design is extremely urgent.Domestic many units have carried out many useful explorations to the development of directing mechanism technology, and the scheme that has has realized through engineering approaches, or even commercialization.Present existing control system is based on single-chip microcomputer, but because the arithmetic speed of single-chip microcomputer is low, the calculating figure place is few, and the function that can realize is very limited, more and more difficulty satisfies the demand for development of following directing mechanism control system.And,, make the reliability decrease of system and system power dissipation also increase because increased control chip, configuring chip and a large amount of storage chips based on the digital control system of DSP+FPGA thereupon.Monolithic FPGA generally is suitable for building of steering logic, and arithmetic capability is very limited, is difficult to realize complex calculations.And existing digitial controller can only also need special position detecting module and chip as motor-driven controller, can not accomplish the set of position-detection sensor and controller.

Summary of the invention

The technical matters that the present invention solves is: overcome the prior art deficiency, a kind of integrated level height, volume and low in energy consumption be provided, and can guarantee higher pointing accuracy the digital control system of satellite aerial directing mechanism.

Technical solution of the present invention: a kind of digital control system for satellite aerial directing mechanism is characterized in that comprising: secondary power supply conversion module, power model, three phase winding testing circuits, synchronous motor, rotary transformer, testing circuit, Hall effect rotor-position sensor, excitatory module, decoder module, spaceborne 28V power supply, power conversion chip, PWM driving circuit, dsp controller, communication module; Spaceborne 28V power supply obtains dsp controller peripheral hardware and the required power supply of kernel by secondary power supply conversion module and power conversion chip, reaches communication module, excitatory module, the needed power supply of decoder module; Simultaneously spaceborne 28V power supply is powered to power model through the secondary power supply module; Synchronous motor output shaft and rotary transformer rotor coaxial are installed; The rotor-position signal of synchronous motor is sent in the dsp controller through the Hall effect rotor-position sensor; In three phase winding testing circuits, be modulated into 0～3V, resistive voltage by testing circuit, is input in the dsp controller, be converted into the winding current signal; During work at first host computer send position command by communication module to dsp controller, the two-way of dsp controller output meanwhile frequency is constant, phase phasic difference 180 is spent and press the PWM ripple that the sinusoidal rule of positive half period changes, two paths of signals is after filtering, rectification and the differential amplification of overexcitation module, output frequency is constant, and the excited signal that the sinusoidal rule of amplitude changes is sent into rotary transformer; Rotary transformer induces the thick level of two-way and the smart level of two-way signal and wherein is thick grade signal by the coil-induced output voltage signal that goes out of thick level, by the coil-induced voltage signal that goes out of smart level is smart level signal, this four road signal is sent into dsp controller after through decoder module filtering, shaping, AD conversion, then by dsp controller through filtering, resolve, obtain final output shaft position signalling after the compensation, error correction; Dsp controller sends the host computer that receives position command and resolves the output shaft position that obtains compares, when the output shaft position equals the given position command of host computer, dsp controller does not have pwm signal output, and PWM driving circuit and power model are not worked; When the output shaft position deviation host computer location of instruction, the synchronous motor rotor position signal that dsp controller obtains by the Hall effect rotor-position sensor, the three-phase winding current that records in conjunction with three-phase winding current testing circuit, process motor vector controlled is resolved and is obtained six road PWM drive signals, output to PWM driving circuit and the work of power model drive motor, finish the position closed loop control of synchronous motor vector controlled current closed-loop and output shaft position signalling, the high precision operation of control satellite aerial directing mechanism.

The present invention's advantage compared with prior art is:

(1) the present invention cooperates function by the monolithic dsp controller with having finished position probing and motor-driven with other related device.And other control modes can only realize motor-driven, also need aided location detection chip and peripheral circuit, by comparison, integrated level of the present invention improves greatly, make the volume and the power consumption of control system all significantly reduce, reduce the controller power consumption, and can guarantee higher pointing accuracy, be specially adapted to Aero-Space etc. have strict demand to power consumption field.

(2) the present invention utilizes dsp controller High-Accuracy PWM, high precision conversion chip and software decode method, has realized the position angle measurement of amplitude discrimination formula angle.Reduce the quantity and the scale of hardware circuit, and guaranteed decode precision.

What (3) the present invention adopted is position, amplitude discrimination formula angle angle-measuring method, and this angle-measuring method has very high requirement to the control system waveform quality.In order to improve the quality that is input to the rotating transformer exciting waveform, dsp controller is other to excited signal output limit priority, and adopts High-Accuracy PWM output.In order to obtain higher decode precision, select the high AD conversion chip of figure place for use, and adopt hardware filtering circuit compensation method, obtain final position signalling by amplitude discrimination formula shaft angle coding/decoding method, and guaranteed the precision of position signalling.

(4) the present invention is because integrated with position probing and motor-driven function, significantly reduced the scale of number of chips and circuit, and motor-driven adopts centrosymmetric six road PWM ripples, has reduced the system switching loss, thereby makes volume of the present invention and low-power consumption further reduce.

(5) compare with existing control mode,, therefore have higher arithmetic speed and precision because dsp controller has the instruction cycle of 150MHz and adopts floating-point operation.

Description of drawings

Fig. 1 is a schematic diagram of the present invention;

Fig. 2 is a motor stator synoptic diagram of the present invention;

Electrical angle spatial division synoptic diagram when Fig. 3 is example for nine Halls of the present invention;

Fig. 4 is rotating transformer exciting circuit figure of the present invention;

Fig. 5 is a rotating transformer exciting oscillogram of the present invention;

Fig. 6 is the smart level two-way circuit diagram in the amplitude discrimination formula shaft angle decoding circuit of the present invention;

Fig. 7 is amplitude discrimination formula shaft angle decoding principle realization flow figure of the present invention;

Fig. 8 is that figure is judged in sine wave permanent magnet synchronous motor SVPWM sector;

Fig. 9 is a control system workflow synoptic chart of the present invention;

Figure 10 is a three-phase winding current testing circuit of the present invention;

Figure 11 is dsp controller of the present invention and extraneous interface circuit.

Embodiment

As shown in Figure 1, the present invention adopts 11 power supplies of spaceborne 28V power supply, spaceborne 28V power supply 11 obtain the dsp controller peripheral hardware by secondary power supply conversion module 2 and power conversion chip 12 and kernel needed+3.3V and+1.9V power supply and communication module 15, excitatory module 9, decoder module 10 needed+5V ,+12V, ± 5V, ± the 12V power supply; Holding circuit 1 is connected with secondary power supply module 2, is used to prevent that electric current is excessive, holding circuit; Secondary power supply module 2 transforms chip 12 with power model 3 power supplys and links to each other, and is respectively applied for to power model 3 and dsp controller 14 power supplies; Send into the rotary transformer 6 by excitatory module 9 from the PWM excited signal of dsp controller 14 outputs, turned back to the dsp controller 14 by decoder module 10 again by energizing signal, finish resolving of output shaft position from rotary transformer 6 outputs; Dsp controller 14 reads the position command of host computer by communication module 15; The rotor-position signal of synchronous motor 5 through Hall effect rotor-position sensor 8, is sent into DSP control wherein with rotor position information; In order to obtain the three-phase winding current, the method by the resistance of crosstalk in three phase windings detects by testing circuit 7, is modulated into 0 ~ 3V with resistive voltage in three phase winding testing circuits 4, be input in the dsp controller 14, is converted into the winding current signal; Dsp controller 14 outputs to drive motor work in the power model 3 by PWM driving circuit 13; In order to make that the output shaft position promptly is to point to mechanism's outgoing position, must make synchronous motor 5 output shafts and the coaxial installation of rotary transformer 6 armature spindles.Concrete workflow is: at first host computer sends position command for dsp controller 14 by communication module 15.Meanwhile, dsp controller 14 output two-way frequencies are constant, phase phasic difference 180 is spent and press the PWM ripple that the sinusoidal rule of positive half period changes, two paths of signals is after filtering, rectification and the differential amplification of overexcitation module 9, output frequency is constant, and the excited signal that the sinusoidal rule of amplitude changes is sent into rotary transformer 6.Rotary transformer 6 induces thick level of two-way and the smart level of two-way signal, wherein thick level signal is by the thick level coil output of rotary transformer, the smart level of two-way signal is the output of smart level coil, this four road signal is through decoder module 10 module filtered, shaping, send into dsp controller 14 after the AD conversion, then through resolving, compensation, obtain final output shaft position signalling after the error correction, promptly thick level and smart level signal are carried out binomial match computing, ask for thick level and smart level position respectively, again thick level and smart level position are carried out error correction, compensation, obtain the final position signal, it resolves principle and process prescription as described in Figure 7.Dsp controller 14 will receive position command and resolve the output shaft position that obtains and compares, and when the output shaft position equaled the given position command of host computer, dsp controller 14 did not have pwm signal output, and PWM driving circuit 13 and power model 3 are not worked.When the output shaft position deviation host computer location of instruction, synchronous motor 5 rotor-position signals that dsp controller 14 obtains by Hall effect rotor-position sensor 8, the three-phase winding current that records in conjunction with three-phase winding current testing circuit 4, by the motor vector control method, realize the High Accuracy Control of satellite aerial directing mechanism.

As shown in Figure 2, Hall effect rotor-position sensor 8 used in the present invention is elected nine as satisfying under accuracy requirement and the situation easy for installation, synchronous motor 5 adopts the hollow cup-shaped winding stator structure of eight pairs of utmost points, no teeth groove iron-free core, is easy to install nine Hall effect rotor-position sensors.On 360 ° of electrical angles of motor stator, evenly place nine Hall effect rotor-position sensors, be used to provide synchronous motor 5 rotor-position signals.

When being illustrated in figure 3 as nine Hall elements of motor stator, in electrical angle space dividing situation in the cycle.Two hall signal electrical angle phases phasic difference 20 adjacent among the figure is spent, and wherein high level is represented with 1, and low level represents that with 0 nine rising edges then are divided into nine intervals with the whole cycle.Synchronous motor 5 of the present invention uses nine Hall elements, eight pairs of utmost point magnet steel, and Hall element is into 40 ° of electrical angles and distributes, and in then whole 360 ° of mechanical angles, then can be divided into 144 electrical angle spaces altogether, and each interval is represented 2.5 °.

Be illustrated in figure 4 as rotary transformer 6 exciting circuit figure, it is the excitatory module 9 that connects dsp controller 14 and rotary transformer.Wherein, PWM7 and PWM8 are the constant frequency PWM signal of dsp controller 14 outputs, generate the constant frequency sinusoidal signal through overexcitation module 9 again, give FX0041, output at last in the rotary transformer 6.

Be illustrated in figure 5 as rotary transformer 6 excitatory oscillograms.Rotary transformer is made up of rotor and stator, and separate, and all on stator, rotor differs 90 ° of coils by two groups and forms for thick level (elementary) and smart level (secondary) coil.Its output voltage is varied to the signal element of certain funtcional relationship with angle of rotor, and when field copper during with certain frequency alternating voltage excitation, the voltage magnitude of output winding becomes sine, cosine function to concern with rotor.Wherein being thick level signal by the coil-induced output voltage signal that goes out of thick level, is smart level signal by the coil-induced voltage signal that goes out of smart level.Obtain behind the two paths of signals signal being resolved.Obtain the tangent signal with the dextrorotation signal divided by the surplus signal that revolves.The tangent signal is asked for arc tangent, obtain thick level and smart level angle value.Thick level angle is rounded, and smart level angle obtains the addition of thick smart level angle the position signalling of rotor divided by 32 (smart level is changeed 32 circles because whenever turn around).The too big point of deviation in the signal compensated obtain available rotor-position signal.Fig. 5 has reflected that PWM excited signal from dsp controller 14 output is to the change procedure that is input to rotary transformer 6 sinusoidal signals.Wherein, give excited signal output high priority level in order to improve signal quality dsp controller 14, and adopt High-Accuracy PWM output module among the TMS320F28335, the output two-way is pressed the pwm signal 16 that the sinusoidal rule of positive half period changes, through obtaining the PWM waveform 17 that sinusoidal rule changes after differential, filtering, the shaping through overexcitation module 9 obtains the constant sinusoidal waveform of magnet excitation frequency 18 again.

Be illustrated in figure 6 as the smart level two-way circuit diagram in the amplitude discrimination formula shaft angle decoding circuit of the present invention.The smart level partial circuit of its representative decoder module 10 of 14 from rotary transformer 6 to dsp controller.FS_SIN wherein, FS_COS are the signal from the output of smart level two-way, through behind the capacitance-resistance filter by AD conversion chip AD976, and, send to dsp controller 14 by 32 position datawires according to its sequential logic.

Be illustrated in figure 7 as amplitude discrimination formula shaft angle decoding principle realization flow figure, rotary transformer 6 essence grade two-way and the waveform of thick level two paths of signals through obtaining respectively after the shaping changing by sine, cosine rule, its amplitude rate of change is by the movement rate decision of output shaft.Wherein, the Changing Pattern of smart level sinusoidal waveform 20 is Smart level cosine waveform 19 is Thick level sinusoidal waveform 22 is

Thick level cosine waveform 21 is ω 0 is an excited signal angular velocity, ω ₁Be output shaft angular velocity, τ is the time,

Be starting phase angle.Read the amplitude of the output signal of current time again through 32 position datawires 23.To become the angle error that output asymmetry and phase shift bring in order reducing to revolve, need to carry out the compensation 24 of sampled value, mainly is to become output asymmetry error and compensate revolving.To carrying out 16 rank FIR filtering 25 after the compensation of four tunnel sampled signals, can compensate to the angle error that shipper pole comes phase place this moment by the software among the DSP.In order to reduce the time of asking the angle computing, adopt the binomial fitting formula of arc tangent curve to carry out the calculating 26 of angle.What the present invention adopted is 21 binary channels of developing, 32 gear ratio rotary transformers 6, and promptly thick level changes one-period, and smart level changes 32 cycles.Combination angle equals 1/32nd sum 27 at thick level residing sector angle of angle and smart angle.Because there is original reason error in thick smart combination, carry out correction process 28 according to smart level and thick polar angle degree relative position relation, obtain final angle measurement signal.

Be illustrated in figure 8 as synchronous motor SVPWM (space vector of voltage width modulation) sector and judge figure.Dsp controller 14 is after obtaining hall signal, and what at first will judge is the residing sector of stator magnetic linkage vector, Flux linkage vector,

For

Component on the β.

Be

Component on V1, V2, wherein V0 (0,0,0), V1 (1,0,0), V2 (1,1,0), V3 (0,1,0), V4 (0,1,1), V5 (0,0,1), V6 (1,0,1), V7 (1,1,1) be eight kinds of duties of three-phase bridge, each scalar of these eight kinds of duty vectors is represented the on off operating mode of three phase windings respectively, and for example V0 (0,0,0) represent all not conductings of three phase windings, V7 (1,1,1) represents all-pass.The judgment principle of sector is:

$a=\left\{\begin{array}{cc}1& S_{\mathrm{\β}}>0\\ 0& S_{\mathrm{\β}}\≤0\end{array}\right.$

$b=\left\{\begin{array}{cc}1& \sqrt{3}{S}_{\∂}-S_{\mathrm{\β}}>0\\ 0& \sqrt{3}{S}_{\∂}-S_{\mathrm{\β}}\≤0\end{array}\right.$

$c=\left\{\begin{array}{cc}1& -\sqrt{3}{S}_{\∂}-S_{\mathrm{\β}}>0\\ 0& -\sqrt{3}{S}_{\∂}-S_{\mathrm{\β}}\≤0\end{array}\right.$

Then sector value is

Sector＝4×c+2×b+a

Vector calculus rule after judging through the sector is an example with sector III:

$\left\{\begin{array}{c}\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="H2009102438170E00011.png,H2009102438170E00021.png"\; state="\{\{state\}\}">T</figure-callout>}1=S_{\&PartialD;}-\frac{\sqrt{3}}{3}{S}_{\mathrm{\&beta;}}\\ \mathrm{<figure-callout\; id="2"\; label="T"\; filenames="H2009102438170E00011.png,H2009102438170E00022.png"\; state="\{\{state\}\}">T</figure-callout>}2=\sqrt{3}{S}_{\mathrm{\&beta;}}\end{array}\right.$

In order to reduce the modulation harmonic wave, three-phase bridge conducting vector often adds zero vector V0 (0,0,0) and full vector V 7 (1,1,1), and makes each voltage vector waveform symmetry.Then ON time is:

$\left\{\begin{array}{c}{t}_{\mathrm{aon}}=\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="H2009102438170E00011.png,H2009102438170E00021.png"\; state="\{\{state\}\}">T</figure-callout>}1+\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="H2009102438170E00011.png,H2009102438170E00022.png"\; state="\{\{state\}\}">T</figure-callout>}2+t_{\mathrm{con}}\\ t_{\mathrm{bon}}=\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="H2009102438170E00011.png,H2009102438170E00022.png"\; state="\{\{state\}\}">T</figure-callout>}2+t_{\mathrm{con}}\\ t_{\mathrm{con}}=(T-T1-T2)/2\end{array}\right.$

If (T1+T2) 〉=T, so,

$\left\{\begin{array}{c}{t}_{\mathrm{aon}}=T\\ T_{\mathrm{bon}}=T*\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="H2009102438170E00011.png,H2009102438170E00022.png"\; state="\{\{state\}\}">T</figure-callout>}2/(\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="H2009102438170E00011.png,H2009102438170E00021.png"\; state="\{\{state\}\}">T</figure-callout>}1+T2)\\ t_{\mathrm{con}}=0\end{array}\right.$

Wherein, taon, tbon, tcon are the ON time of three phase windings.

Be illustrated in figure 9 as control system workflow synoptic chart of the present invention.After system powered on, dsp controller 14 was accepted host computer position command information by communication module 15, compared with the angle behind the demoder.If the location deviation, then drive motor carries out work, otherwise waits for the position command that reception is new.When the output shaft position arrives the target location, wait for new position command, otherwise motor will work on, up to reaching angle on target.

Be three-phase winding current testing circuit 4 of the present invention as shown in figure 10.MEASURE_iu is the detection electric current of a wherein phase winding, draws high through being biased signal BIAS_ia behind the follower, through after the second-order filter detection signal is adjusted between 0～3V, gives dsp controller 14.

Be dsp controller 14 and extraneous interface circuit as shown in figure 11.Mainly comprise: excited signal interface 29, shaft angle decoded signal data incoming end 30 and steering logic signal, the outer RAM storage chip interface 31 of sheet, nine road hall sensor signal interfaces 30, six road pwm power drive signal interfaces 32, with the communication interface 33 of host computer, current sampling signal interface 34, jtag interface 35.

Claims (5)

1. a digital control system for satellite aerial directing mechanism is characterized in that comprising: secondary power supply conversion module (2), power model (3), three phase winding testing circuits (4), synchronous motor (5), rotary transformer (6), testing circuit (7), Hall effect rotor-position sensor (8), excitatory module (9), decoder module (10), spaceborne 28V power supply (11), power conversion chip (12), PWM driving circuit (13), dsp controller (14), communication module (15); Spaceborne 28V power supply (11) obtains dsp controller (14) peripheral hardware and the required power supply of kernel by secondary power supply conversion module (2) and power conversion chip (12), reaches communication module (15), excitatory module (9), the needed power supply of decoder module (10); Spaceborne 28V power supply (11) is given power model (3) power supply through secondary power supply module (2) simultaneously; Synchronous motor (5) output shaft and rotary transformer (6) rotor coaxial are installed; The rotor-position signal of synchronous motor (5) is sent in the dsp controller (14) through Hall effect rotor-position sensor (8); Resistive voltage by the testing circuit (7) in the three phase winding testing circuits (4), is modulated into 0～3V in three phase winding testing circuits (4), is input in the dsp controller (14), be converted into the winding current signal; During work at first host computer send position command for dsp controller (14) by communication module (15), the two-way of dsp controller (14) output meanwhile frequency is constant, phase phasic difference 180 is spent and press the PWM ripple that the sinusoidal rule of positive half period changes, two paths of signals is after filtering, rectification and the differential amplification of overexcitation module (9), output frequency is constant, and the excited signal that the sinusoidal rule of amplitude changes is sent into rotary transformer (6); Rotary transformer (6) induces thick level of two-way and the smart level of two-way signal, wherein be thick level signal by the coil-induced output voltage signal that goes out of thick level, by the coil-induced voltage signal that goes out of smart level is smart level signal, this four road signal is sent into dsp controller (14) after through decoder module (10) filtering, shaping, AD conversion, then by dsp controller (14) through resolving, obtaining final output shaft position signalling after the compensation, error correction; Dsp controller (14) sends the host computer that receives position command and resolves the output shaft position that obtains compares, when the output shaft position equals the given position command of host computer, dsp controller (14) does not have pwm signal output, and PWM driving circuit (13) and power model (3) are not worked; When the output shaft position deviation host computer location of instruction, synchronous motor (5) rotor-position signal that dsp controller (14) obtains by Hall effect rotor-position sensor (8), the three-phase winding current that records in conjunction with three phase winding testing circuits (4), process motor vector controlled is resolved and is obtained six road PWM drive signals, output to PWM driving circuit (13) and power model (3) drive motor work, finish the position closed loop control of synchronous motor (5) vector controlled current closed-loop and output shaft position signalling, the high precision operation of control satellite aerial directing mechanism.

2. a kind of digital control system for satellite aerial directing mechanism according to claim 1 is characterized in that: the preceding holding circuit (1) that is connected to of described secondary power supply module (2) is used for overcurrent protection.

3. a kind of digital control system for satellite aerial directing mechanism according to claim 1 and 2, it is characterized in that: described synchronous motor (5) adopts the hollow cup-shaped winding stator structure of no teeth groove iron-free core, on 360 ° of electrical angles of motor stator, evenly place nine Hall effect rotor-position sensors, be used to provide synchronous motor (5) rotor-position signal.

4. a kind of digital control system for satellite aerial directing mechanism according to claim 1 and 2 is characterized in that: described dsp controller (14) is as follows through the concrete steps of resolving, obtain after the compensation, error correction final output shaft position signalling:

(1) thick level and smart level signal are carried out binomial match computing, ask for thick level and smart level position respectively;

(2) thicker level and smart level position are carried out error correction, compensation, obtain the final position signal.

5. a kind of digital control system for satellite aerial directing mechanism according to claim 1 and 2 is characterized in that: described dsp controller (14) adopts the TMS320F28335 of TI company.

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