Method for overcoming motor dead zone and improving radar tracking precision in speed ring

Technical Field

The invention relates to tracking radar servo control system processing speed ring motor dead zone method.

Background Art

Tracking radar servo system as a drive radar antenna operation of the actuating mechanism, is a rather special follow-up system, is composed of a servo-mechanical structure and of the servo controllers. Main effect is based on the command and error integrated calculation, control motor drive radar antenna as to follow the motion of a target, and real-time accurate measuring radar machinery for encoding the position of the shaft. Radar servo system is one comprising azimuth axis, pitching shaft and a cross roller bearing of the three shaft system, it is typical of electromechanical integration system. Since for a long time, the radar servo system to the electromechanical integration system, either in theory or in engineering design, have been artificially divided in two parts: a mechanical part and a control part. Radar servo system according to the control algorithm of the control quantity calculated in real time, the driving voltage of output by the controller to the driver, driver for power amplification control operation of the motor, the operation of the radar antenna is realized. Radar servo system is a more complex electromechanical system, such as the presence of mechanical friction, the drift of the circuit parameters, shafting between the coupling torque, environmental interference and shafting between handing over vertical degrees or is not caused by the imbalance of load moment, the radar antenna and caused by insufficient rigidity of the mechanical deformation and load fluctuations, the motor is non-linear characteristic of the cogging effect, and the like, therefore, radar servo system is a non-linear and not with very strong certainty the position/speed servo system. In the drive element of the radar servo system of the electric motor, the electric motor is essentially a closed-loop system of the position or speed, the motor is a high-order, non-linear, strong coupling of the complex multivariable system. The low speed of the observed values deviate from the actual value of the dead zone, and this kind of deviation occurred in the system the feedback link of the inner ring, resulting in decline in low speed stability of the system. The dead zone of the motor there are no-load deadzone voltage and load deadzone voltage; no-load deadzone voltage means without any load on the motor shaft, in other words only the operation of the motor when the operation voltage of the dead band of the motor shaft, if the exclusion of the motor when the production rotor winding of the fabrication process of the consistency not, at any angle of the motor shaft, the dead zone voltage range [V_S-, V_S+] are the same; voltage means the dead zone of the load with a load on the motor shaft, the operation of the motor, will drag the coaxial load when the voltage of the dead band of the synchronous rotation, the dead zone of the load voltage due to the impact of a plurality of non-linear factors, the angle of the motor voltage different consistency of the dead zone, the dead zone of the load voltage range and no-load deadzone voltage range is larger than the bound. The dead zone is usually the motor armature voltage to start from zero to, when the rotation of the motor can be the voltage of the voltage is known as the dead zone, the dead zone voltage is lower than the motor can not be rotated, the motor could be positive, reverse running, the deadzone voltage there is also positive, negative polarity, negative polarity dead zone voltage V_S- dead zone of the positive polarity voltage V_S+ this voltage area between [V_S-, V_S+] referred to as motor dead zone.

The control algorithm for the servo system is to control the optimization of the study of the theory has been hot, but also to drive radar antenna operation of the actuating mechanism of one of an important source of the performance of the radar servo system, provides increasingly higher requirements. In the radar tracking process various non-linear factors, is bound to lead to the control system to have difference tracking. Tracking radar system non-linear factors of the rigidity of the operational amplifier element, saturated non-linear, non-linear error, the friction of the non-linear, the imbalance torque of the heavy load, the feedback element quantization error, the resonant structure, wind changes, transmission delay jitter, such as temperature drift of the control circuit, on the one hand, the existence of these factors for generating a static error, on the other hand, it also results in the uncertainty of the random error. Any motor will inevitably exist voltage dead zone, the dead zone voltage will lead to the low-speed target and radar tracking is not uniform "run-out" or "creeping" phenomenon, will inevitably affect the precision tracking radar tracking accuracy. Because the radar system the impact of various non-linear factors, presence of the dead zone voltage of the motor. In order to achieve high precision stable tracking, the servo system the current loop design in general, speed ring, position ring tricyclic control scheme. Servo controller for closed-loop function of the ring completed position, servo driver completed and the speed of the current closed-loop function of the ring. snap ring ring of the current and the speed of the inner ring. The current normally, speed ring design as a proportional, integral, and differential control, position ring design as a proportional, integral control. The design process is in general from the inside to the outside, in the current design, speed ring and position ring, according to the performance index of the whole system, appropriate distribution of the design index of the corresponding, according to the typical system design control and compensation unit. Servo system normally consists of a current, speed, position of a three loop, the current loop is a part of the speed loop, speed loop is designed on the basis of the position loop; the main role of the current loop is to reduce the time constants of the armature circuit, the sight under the influence of the back electromotive force of the motor, the structural resonance of certain inhibiting role a; speed loop time constant can be reduced, improving loop of the dynamic characteristic, increase the margin of the phase angle of the system, to improve the quality of the transition process of the system, the low-speed stability of the system, the regulating range of the expanded system; according to the role of the position loop is command radar work, to realize accurate positioning and position follow-up.

Tracking radar servo system often require relatively high tracking accuracy. The feed-forward compensation and fuzzy PID control are combined to form a mixed intelligent control strategy. At present is suitable for radar servo system precision position control method is of the classic PID, PID and feed forward composite control, modern adaptive control, variable structure control, intelligent dynamic robust compensator control, inverse model of neural network, the neural network parallel control, the sliding mode control, and the like. In the forming the radar equipment, servo-system multi-control circuit adopts the basic PID control, some loop even PI control. Although simple structure and can be the operability is strong, but adjustable parameters. PID is a proportional (P), integral (I), the differential (D) the closed-loop-control algorithm, PID algorithm to be achieved, must be in hardware is provided with a closed-loop control, , there must be a feedback. For example, control a rotational speed of the motor, have a measuring motor speed sensor, and sends the results back to the control circuit. PID control algorithm is not a must at the same time with these three kind of algorithm, also can be PD, PI, or even only P algorithm control. Proportional (P), integral (I), the differential (D) control algorithm a function of the: proportion of the current reaction system the basic deviation e (t), coefficient is large, the adjusting can be speeded up, reduce the error, is too large, however, the proportion of the decrease in stability of the system, and the system is not stable. Electronic calendars of integral reaction system, because there is an error, an integral adjusting it to continue, until the error-free. Differential reflect the rate of change of the system deviation signal e (t)-e (t-1), with predictable, can be foreseen, the trend of change in the deviation, the control action of the generated advance, before the deflection is not formed, has been differential regulation function to dispel and, therefore, the dynamic performance of the system can be improved. However, differential to noise interference with ampn, strengthen anti-interference negative differential to the system. Integral, and differential are alone can't play a role, the proportional control must be. The automatic control system in overcoming errors may occur in the regulating process of the oscillation even jitter, its reason is that a relatively large inertia assembly due to the presence (link) or lag (delay) assembly, has the role of suppressing error, the change always lag behind the change of the error. Introduced only in the controller "proportional P" often is not enough, the role of the proportional term is the amplitude of the error amplified only, "differential a" trend of error change can be predicted. The so-called "error" is the difference between the command and the output. For example, to controlling the hydraulic pump speed is 1500 transfer (=6V "command voltage"), and in fact the control hydraulic pump speed only 1000 rotation (output voltage = 4V), the error: e=500 rotary (corresponding voltage 2V). The pump the actual rotational speed is 2000 turn, the error e=-500 rotating. The error difference is sent to the PID controller as the input of the PID controller. The output of the PID controller: error Kp* +Ki* error integral +Kd* error differential, in other words Kp*e+Ki * ∫edt+Kd * (de/dt), in the formula t for time, that is, to the time integral, differential. Aboving to three summing, PID result into the motor driver. Seen from the above formula, if there is no error, in other words e=0, the Kp*e=0 ; Kd*(de/dt)=0 ; and Ki*∫edt necessarily the 0. Three and is not necessarily 0. In short, if there is "error", the frequency converter on the PID will be adjusted, until the error = 0. Whether the evaluation of a superior control system, there are three indicators: fast, stable, quasi-. The so-called fast, it is necessary to make the pressure can quickly reach the command value. The so-called stable pressure is stable without fluctuation or fluctuation is small, the so-called quasi-, are required between the command value and the output value of the error e is minimized. The fast system requirement, Kp can be increased, the value Ki, request prospective, Ki value can be increased, the stable, Kd value can be increased, pressure fluctuation can be reduced. Analysis of the three indicators are mutually contradictory. If it is too fast, may lead to unstable; if it is too stable, is likely to lead to fast; as long as the system is stable and have integral Ki, system there is no error in a static state (there will be dynamic error); the so-called dynamic error means when the command value is not to be a constant value, with the command value to the output value of the error. The system is dynamic error, is embodied in the dynamic error of tracking performance of the system. As can be seen from the above analysis, either position control or speed control, the control core of the radar servo system snap ring control algorithm is, it is the protection of system control precision. Tracking radar servo system more commonly used three loop of the control algorithm is PID algorithm, that is, a proportional-integral-differential algorithm. The tracking radar servo control system in the digital servo control system, the PID algorithm adopted by the expression of:

u(k)=Kpe(k)+TKΣj=1ke(j)+KdT[e(k)-e(k-1)]......(1),

In the formula, u (k): sampling time the output signal of the controller; e (k): k time input error value sampling time, is equal to the difference between the measured value and the given value; K_p: of the proportional coefficient of the controller; K_i: integral factor of the controller; K_d: differential coefficient of the controller; T: sampling cycle. Precision tracking radar servo system generally adopts a non-static differential system. The actual radar servo system there are various non-linear factors, for example, the rigidity of the servo circuit in the, slope non-symmetrical, saturated non-linear, friction non-linear, antenna heavy torque imbalance, feedback element quantization error, the resonant structure, wind changes, transmission delay jitter, etc., will certainly lead to poor radar servo system to a tracking, in various non-linear factors under the influence of, the drive motor is dead zone voltage is increased, the servo controller outputs a range of small voltage and the phenomenon of the antenna does not move, the target is moving, the dead zone, i.e. the motor lead to tracking error is increased, the only when the tracking error, servo controller output beyond the dead zone range of movement only of the antenna, to this end, certain measures need to be taken to reduce the tracking error, improve tracking precision. The present invention is directed to tracking process the dead zone to a motor in the tracking error of a practical method, in order to rapidly eliminate the dead zone of the motor the impact of tracking accuracy, can effectively solve the low-speed target and radar tracking antenna creeping phenomenon.

Content of the invention

The purpose of this invention is for traditional PID control can not realize the control of the self-setting parameter, the introduction of intelligent PID control, can be effectively improved to provide a radar tracking accuracy, rapid diagnostic radar whether the motor dead zone range work, in a timely manner due to the elimination of the motor can not eliminate the dead zone and method of tracking error.

The above object of the present invention is realized through the following measures. A motor in the speed ring to overcome the dead zone to improve the precision of the radar tracking method, which is characterized by comprising the following steps: in the tracking radar servo control system, in accordance with the current loop, speed ring, position ring tricyclic control scheme, the establishment of a driver for the motor current feedback, torque motor to the motor speed feedback, radar antenna to the antenna position feedback to the servo controller of the three closed loop control circuit; the ring comprises the electric current in drive, current ring design as a proportional, integral, and differential control, speed ring taken as proportional, integral control, position ring taken as proportional, integral control of the three closed-loop PID (proportional, integral, differential) control servo system loop, and with the speed ring as the input of the output of the current loop, the current to the motor current as the negative feedback, the output of the with the position ring as the input of the speed ring, to the speed of the motor as the negative feedback of the speed ring, by the radar letter place error as the position ring input, by the radar antenna as the position of the ring the position of the negative feedback; servo-controller built-in arithmetic processor receiving and implementation of radar terminal system radar and the control command sent the error message of the system sends letter place ; arithmetic processor speed ring of a built-in motor dead zone detection software program for the error of the loop proportional-integral PI correction processing, the generated is directly proportional to the speed of the motor with the output voltage of the driver (quantity), the servo controller driver output voltage of the power amplifier, driving torque operation of the motor, drives the radar antenna movement; in a tracking process torque motor servo controller detects the position of the output voltage and the antenna, the antenna operational processor periodically coding and speed ring the position of the detected output voltage, output characteristic of the detection of the servo controller the position of the antenna characteristic, when the servo controller speed ring indicators output beyond the most low-speed range when the antenna position, immediately to the servo controller speed ring the voltage of the output compensation with the same polarity, the output of the speed ring as the input current, through the current PID correction processing the output voltage to the driver, thereby pushing the antenna operation, in order to overcome the dead zone of the motor, to overcome the dead zone, the compensation voltage is reduced gradually to zero, the servo controller speed ring to recover to a normal operational processing mode.

The invention compared with the prior art has the following beneficial effects.

The invention three closed-loop regulating the servo control system, provides servo system and servo control in the design of the control strategy, the position of the construction on the basis of the algorithm, speed, current three closed-loop control system. Servo controller adopts the current loop, speed ring, position ring comprised of three closed-loop PID (proportional, integral, differential) control strategy, the current to the motor current as the negative feedback, to the speed of the motor as the negative feedback of the speed ring, by the radar antenna as the position of the ring the position of the negative feedback, the error for each loop PID correction processing, through the current loop generates the output voltage to the driver; a driver the controller output voltage of the power amplifier, driving operation of the motor, the motor drives the coaxial radar antenna to reduce the direction of the tracking error of movement, the tracking error is minimized.

The present invention current ring design into the current loop negative feedback can fully utilize the overload capacity of the allowed by the motor, at the same time the maximum value of the limiting current, the motor starting or brake play the fast protection role. Current loop of the controller is directly realized in the circuit of the power amplifier of the hardware. Through specific experimental verification result shows that, current loop loop fast response speed, no overshooting or overshoot is very small. The current ring is introduced in the control of the appropriate, current can be poor the link is not static to tracking step signal, effectively reduce the time constant of the circuit of the motor, in order to improve the speed ring bandwidth, the speed of the design has a quick response to lay a good foundation ring controller. In the specific design of the current, the armature current of the power amplifier and for the relationship between an inertial link to equivalent.

This invention utilizes the high-speed arithmetic processor, flexible operational characteristics and high-speed operation processing function, the radar detection process of tracing the, through the dead zone of the motor voltage is compensated, can overcome the presence of the dead zone of the motor voltage tracking error caused by the temperature rise of the motor and the increase of the resonance frequency caused by the drift, the amplitude of the stator is basically stable, and is not the amount of the increase in the field of hardware facilities, but fully utilize the processing capacity of the arithmetic processor, a tracking error can be quickly reduce, improve tracking performance, can effectively solve the radar tracking low-speed target radar antenna of the phenomenon of "creeping", low speed is reduced the error is not stable at the time of tracing, can make the radar position encoding curve more smooth.

In the invention, the speed ring is designed as PI control, the output of the speed ring to follow the change of the input quantity, control servo system loop, on-line offset voltage the influence of the servo system, thus to improve the low speed performance of the system. Because the output of the speed ring directly into the input of the current, into the current loop so as to fundamentally overcome the dead zone effect.

The invention is based on the platform for tracking the radar system; a servo control system for controlling the speed of the radar antenna according to the designated motion, to realize stable tracking of the target; tracking servo controller detects the position of the output quantity and the antenna, to judge whether the controller speed ring to output more than the required minimum number of low-speed range and a radar antenna position still, once the conditions are satisfied, the controller speed ring immediately output compensation proper amount of quantity, in order to overcome the dead zone of the motor; to overcome the dead zone of the motor, gradually reduced until the compensation voltage is zero compensation.

Description of drawings

With the embodiment of the Figures and further explanation of the present invention.

Figure 1 is the tracking radar servo control system structure diagram.

Figure 2 is the dead zone of the motor servo control system a schematic diagram of the positive compensation voltage curve.

Figure 3 is the dead zone of the motor servo control system compensation voltage curve a schematic diagram of negative polarity.

Mode of execution

Figure 1 the servo control system is shown by the servo controller, driver, torque motor, radar antenna. Servo controller, driver, torque motor belongs to the radar servo control portion of the system, the radar antenna to the mechanical parts of the radar servo system, servo controller for completion of information acquisition, and a computation processing, generate an output voltage to the driver, the driver is used for the output voltage of the servo controller are power amplified to drive the torque operation of the motor, with the axis of rotation of the torque motor the rotation of the radar antennas and shaft are coaxial, so that the operation of the electric motor will drive the radar antenna synchronous operation. Motor current feedback, motor speed feedback, antenna position feedback form three closed-loop control of the servo tracking radar servo control system. Servo control system for controlling the speed of the radar antenna according to the designated motion, the goal of realizing stable tracking. Servo controller receives and implementation of radar terminal system and the control command sent radar letter place system sends tracking error information, radar tracking drive motor in order to eliminate the movement of the for the purpose of error, motor drive coaxial radar antenna movement. A set up according to this invention by the servo controller, driver, torque motor, radar antenna, motor current feedback, motor speed feedback, antenna position feedback comprised of three closed-loop control of the tracking radar servo control system; the servo controller comprises a high-speed arithmetic processor, arithmetic processor receiving and implementation of radar terminal system and the control command sent radar letter place system sends the error information, radar drive torque motor in order to eliminate the movement of the tracking error for the purpose of; the servo controller for the control strategy of the current loop, speed ring, position ring comprised of three closed-loop PID (proportional, integral, differential) control; with the speed ring as the input of the output of the current loop, the current to the motor current as the negative feedback of the; output as of the ring in order to position the input of the speed ring, to the speed of the motor as the negative feedback of the speed ring; by the radar letter place error as the position ring input, by the radar antenna as the position of the ring the position of the negative feedback, the error for each loop PID correction processing, the output of the current as the controller output voltage to the driver; a driver the controller output voltage of the power amplifier, driving torque operation of the motor; the greater the output voltage, the faster running speed of the motor, that is, the output voltage is directly proportional to the speed of the motor. The processor of the servo controller periodically collecting the input information and the feedback information, the position-coding of the antenna is detected and the output voltage, and calculated according to the current PID control strategy, speed ring and snap ring , when the servo controller output voltage is compared for hour, the output torque of the motor is not enough to overcome the static friction, the antenna does not move, only when the output voltage exceeds the dead zone of the motor voltage, the antenna can be motion; the presence of the dead zone voltage affect the tracking precision of the system, the need to overcome; the position of the servo controller to the antenna for detecting the voltage and the output of, judging whether there is the output voltage of the motor does not move, the servo controller output voltage is within the range of the dead zone; if the motor is in the deadzone voltage range, and servo controller also hope operation of the motor, the servo controller in accordance with the output voltage of the same polarity the polarity of the voltage of the compensation amount, in order to overcome the dead zone of the motor, the operation of the motor, the operation of the motor, the static friction into the dynamic friction, reduced friction; to overcome the dead zone, the compensation voltage is reduced gradually to zero, the servo controller to recover to a normal operational processing mode. Stable precision tracking radar tracking, the tracking error in an index in the range of zero-error as a reference the changes in small range, if the polarity of the tracking error is always a fixed positive polarity or negative polarity, the tracking presence of advance or lag behind; if the tracking error in the vicinity of zero error is very small fluctuations, the tracking performance is good. Processor judges whether there is a servo-controller output more than the required minimum number of low-speed range of the radar antenna position, once the conditions are satisfied, to the servo controller to the voltage of the output compensation amount, in order to overcome the dead zone of the motor; to overcome the dead zone of the motor, gradually reduced until the compensation voltage is zero compensation. Servo controller antenna is measured in advance in a plurality of different angles of the dead band of the voltage, then averaging, the load voltage range of the dead band of the obtained [V_S-, V_S+], V_S- dead zone voltage to negative polarity, V_S+ dead zone voltage to a positive polarity.

The embodiment that the voltage is of the dead band of the dead zone of the load voltage. The antenna servo-controller for the position of the detection voltage and the output of, judging whether there is the output voltage of the motor does not move, the position of the antenna to the coaxial with the motor position-coding of the absolute position of the antenna element, which is used for representing the current absolute position of the antenna, the said absolute position in the range of 0 °-360 °. Servo controller through the speed ring output voltage to the driver, the output voltage magnitude proportional to the desired motor speed, the servo controller may periodically reading the position-coding, and according to the position of the front and back cycle to determine whether to change values whether antenna motion, if servo controller with an output voltage, the antenna do not move, it indicates that the system work in the motor dead zone range.

Servo control system within the current loop is integrated in the drive, servo controller only needs to carry on the speed ring and of the operation processing snap ring , therefore, overcome electric motor the dead zone of the processing method is the process is complete in the speed ring. Tracking radar system load deadzone voltage due to the impact of a plurality of non-linear factors, the angle of the motor voltage different inconsistency of dead zone. In order to facilitate the servo controller computing and processing, needs to pre-measure the antenna in a plurality of different angles of the dead band of the voltage, then averaging, to obtain the load voltage range of the dead zone speed ring [V_S-, V_S+]. Position control system for the speed ring is in one of the links is very important. The role of the speed ring to: ensure steady-state accuracy of the speed loop. The design of the speed ring, can consider speed ring controller includes an integration element, in order to overcome the dead zone of the servo motor and power amplifier caused by the drift of a static error, the indicators steady-state accuracy, improve system static rigidity. The closed-loop characteristic of the speed ring is designed to be over-damping, so that the dominant pole is a the solid pole, thus help to overcome the effects of friction, improved servo-motor low speed operating characteristics. The speed can also be used as a speed feedback element of the generator, form analog speed feedback system. Position ring controller is a digital controller utilizing a computer to realize. When the tracking radar servo system when the tracking control of the speed is performed, because can only collection to an accurate position signal, there are no precise speed measurement element, using the method of the differentiating the position signal to obtain a speed signal, then position closed-loop control, the accuracy of the ring with the position to ensure the precision of the speed. Radar terminal system and sends control commands from the servo controller receives the current state of system information; the tracking radar communication of servo control system, a corresponding control command. Radar terminal system complete system's data acquisition, system current state of the control quantity calculation and real-time task monitoring, and the like.

Tracking radar antenna angle that is, the position-coding, the coaxial rotating shaft with the antenna element obtain the location encoding of, servo controller may periodically obtain the position coding. Servo controller with fixed speed ring of the operation processing cycle, the present invention in order to 2ms time period of the speed ring, the position-coding use 18 bits show as an example note processing method. 18 bit of the position-coding of the quantization unit 360 / (2¹⁸) =0.00137°, if the radar system calls for the lowest speed of 0.05 ° / s, then 14 processing cycle (28ms), the position-coding change a quantization unit, therefore, required to judge the position changes with the location encoding of the cycle 28ms before comparing the location encoding of, determine if changes have occurred, the first-in first-out (FIFO) queue array uses advanced way keep the last continuous 15 cycle of the position-coding, compare the 1 cycle and 15 the location encoding of a cycle, can be determined whether to change the position of the antenna, if the antenna position is changed, the sign Flag=0, otherwise Flag=1.

Servo controller in accordance with the output voltage of the same polarity the polarity of the voltage of the compensation amount, in order to overcome the dead zone of the motor, the operation of the motor, means in the output voltage when the servo controller [V_S-, V_S-/2] or [V_S+/2, V_S+] range, antenna not running, the servo controller output need of compensation; if the output in a range of [V_S-, V_S-/2], the polarity of the compensation of the negative voltage, the compensation voltage heating V_S-/4; if the output in a range of [V_S+/2, V_S+], compensation polarity is a positive voltage, the compensation voltage heating V_S+/4; the output voltage when the servo controller [V_S-/2, V_S+/2] range, if not compensated, this is because the radar each system itself the presence of noise, is sent to the servo controller system letter place error will inevitably contains noise information, even if the radar antenna at the target center, letter error also is not likely to be accurate is to give stable zero error, servo controller output voltage is also necessarily contains noise information. In order to avoid radar tracking the oscillation of the static, servo controller output voltage is less than the dead zone voltage when the half output not to compensate the weak.

When the output voltage of the speed ring [V_S-, V_S-/2] or [V_S+/2, V_S+] range, if the state flag register flag Flag=1, that motor is in the dead zone, and the purpose of the servo controller is driving operation of the motor, the presence of the dead zone of the operation of the motor, one can only rely on speed ring integral gradually accumulate, accumulated to exceed the dead zone voltage, motor will only operate. In order to overcome the dead zone of the motor as soon as possible of the hysteresis operation of the motor, servo controller active according to the output voltage of the same polarity the polarity of the voltage of the proper amount of compensation, can be quickly drives the electric motor is running, if the output voltage in a range of [V_S-, V_S-/2], the polarity of the compensation of the negative voltage, the compensation voltage heating V_S-/4, the output voltage range [V_S+/2, V_S+], compensation polarity is a positive voltage, the compensation voltage heating V_S+/4; compensation voltage is directly superimposed on the output voltage; if the compensation voltage of certain antenna position after adding still can not drive the antenna, depends on integration accumulation, will eventually promoting antenna operation, but there is a lag; when the controller output voltage in [V_S-/2, V_S+/2] range, not be compensating.

After adding the compensating voltage, the arithmetic processor continue to judge state flag register Flag sign, sign Flag once the status flag register = 0, indicates that the antenna has been overcome in the operation of the dead zone of the motor voltage, the compensation voltage is gradually reduced according to the cycle, each cycle of the compensation voltage is reduced 1/10, 10 after a cycle is reduced to zero. To overcome the dead zone of the motor, the compensation voltage is reduced gradually to zero, the servo controller to recover to a normal operational processing mode, refer to the code judging apparatus according to the position of the antenna motion, the compensation voltage is not immediately revoke, but is gradually reduced in accordance with the calculation cycle, so far until the reduced to zero. The speed ring calculation cycle described herein for 2ms, is divided into 10 time is reduced, reducing the period of each of the compensation value is the compensation voltage 1/10.

Figure 2 in the servo controller shown t1 positive voltage output at all times when the range of the dead zone, the dead zone of the motor a schematic diagram of the positive compensation voltage curve. The servo controller t1 time compensating voltage of V_S+/4, then divide, 10 time decreasing the compensation voltage, to t1 + 20ms time, the compensation voltage decrement to zero.

Figure 3 in the servo controller shown t2 moment when the range of the negative voltage output from the dead zone, the dead zone negative polarity compensation voltage curve of the motor a schematic diagram, the servo controller t2 time compensating voltage of V_S-/4, then divide, 10 time decreasing the compensation voltage, to t2 + 20ms time, the compensation voltage decrement to zero.