CN103786605A - Automobile seat position determination and adjustment - Google Patents

Abstract

The invention relates to the technology of automobile electronics, particularly to an automobile seat position determination and adjustment method and an automobile seat position adjustment system. The automobile seat position adjustment method comprises the following steps of determining the required number of revolutions of a DC (direct current) motor according to a current position and a target position of a seat; starting the DC motor to obtain the sampling value of the current waveform of the DC motor, wherein the current waveform contains ripple wave components; transforming the sampling value of the current waveform to obtain a transformation value; summing the transformation value in time to obtain a sum and according to the sum, controlling the DC motor to rotate at the required revolutions. According to the automobile seat position determination and adjustment method, by determining the number of the revolutions of the motor through the ripple wave components of the current waveform, the trouble of mounting multi-stage magnetic rings can be omitted.

Description

Determining and adjusting of automotive seat position

Technical field

The present invention relates to automotive electronic technology, particularly for determining and adjust method and the automotive seat control system of automotive seat position.

Background technology

Automotive seat must meet the requirement of traveling comfort, namely can make driver obtain the best visual field, obtain being easy to steering dish, pedal, shifter bar etc. handle convenient, can also obtain the most comfortable and be accustomed to most take angle.But everyone build is not quite alike, and also can change with advancing age, therefore in design when driver's seat, design engineers can only be according to the be grown up statistics of stature of somewhere, finds out average data and designs and drive space and seat.

Draw thus second of automotive seat basic demand-controllability.On modern automobile, manufacturer can provide seat that can motorized adjustment.Automatic seat is generally made up of seat cushion, backrest, headrest, skeleton, suspension and regulating mechanism etc.Regulating mechanism is made up of controller, DC motor and drive disk assembly, is the part of the most complicated in automatic seat and most critical.DC motor generally has more than three, and they are controlled by the controller and drive respectively certain to adjust the drive disk assembly of direction.Drive disk assembly has worm shaft, worm gear, tooth axle and tooth bar etc.When adjustment, worm shaft, under the driving of electrical motor, drives worm gear to rotate, thereby tooth axle is screwed in or screw out the i.e. lifting of seat.If worm gear engages with tooth bar again, worm gear rotates tooth bar is moved, even seat reach or after move.For medium-to-high grade car, be also equipped with steering position to regulate memory setting, memory content for example comprises that seat adjustment position, steering handwheel adjusting and exterior mirror etc. regulate memory.

Fig. 1 shows a kind of automotive seat control system with typical structure.

As shown in 1, this automotive seat control system 10 comprises DC machine 110, current detecting unit 120, controller 130, relay 140 and Hall element 150.Controller 130 is controlled the running of DC machine 110 by the on off mode of control relay 140.On the rotating shaft 110A of DC machine 110, be bonded with multi-pole magnet-ring 110B, Hall element 150 is arranged near rotating shaft 110A, like this in the time that rotating shaft 110A rotates, near each magnetic pole of magnet ring 110B turns to Hall element 150 time, will be at the interior generation Hall of Hall element 150 impulse singla, this impulse singla has reflected the position signal of seat indirectly.Referring to Fig. 1, this pulse detection signals is fed back to controller 130, and thus, DC machine 110 can be rotated the required number of turns under the control of controller 130.In addition, in the loop at DC machine 110 places, also access current detecting unit 120, it exports the current signal detecting to controller 130, such as, to be judged the running state (level of torque, whether occur stall etc.) of DC machine 110 by controller 130.

In above-mentioned automotive seat control system, adopt the method based on Hall element to determine seat position, there is more shortcoming in this.For example, in order to produce Hall impulse singla, multiple magnet rings need to be installed on machine shaft, this has increased manufacture and cost of installation, and along with the continuity of period of service, magnet ring also easily comes off from rotating shaft.

Therefore, in the urgent need to a kind of automotive seat control method and system that can overcome above-mentioned shortcoming.

Summary of the invention

The object of this invention is to provide the method for a kind of definite automotive seat position, it has advantages of that the cost of realization is low, accuracy is high.

Above-mentioned purpose of the present invention is realized by following technical proposal:

A method for definite automotive seat position, described automotive seat are driven by DC machine, comprise the following steps:

Obtain the sampled value of the current waveform of described DC machine, described current waveform comprises ripple component;

The sampled value of described current waveform is carried out to conversion process to obtain conversion process value;

Described conversion process value is sued for peace to obtain summing value in time; And

Determine the current location of described automotive seat according to the reference position of described summing value and described automotive seat.

Preferably, in said method, according to following manner, the sampled value of described current waveform is carried out to conversion process:

$I_i^{\mathrm{Tran}}=\frac{\mathrm{Max}(I_i,I_{i-1...}{I}_{i-n+1})-I_i}{\mathrm{Max}(I_i,I_{i-1}...I_{i-n+1})-\mathrm{Min}(I_i,I_{i-1}...I_{i-n+1})}$

Here I _ibe i sampled value, I _i ^tranbe the transformed value of i sampled value, Max (I _i, I _i-1i _i-n+1) be the maxim of nearest n digitalisation sampled value, Min (I _i, I _i-1i _i-n+1) be the minimum value of nearest n digitalisation sampled value.

Preferably, in said method, the voltage accessing by measurement on the resistor in described DC machine loop obtains described current waveform.

Preferably, in said method, described reference position is last time post exercise positions of described automotive seat.

Preferably, in said method, the end position that described reference position is described automotive seat, and periodicity or the described reference position of calibration, aperiodicity ground.

The control method that also has an object to be to provide a kind of automotive seat position of the present invention, it has advantages of that the cost of realization is low, accuracy is high.

Above-mentioned purpose of the present invention is realized by following technical proposal:

A control method for automotive seat position, described automotive seat are driven by DC machine, comprise the following steps:

Determine according to the current location of described automotive seat and target location the number of turns that described DC machine need to be rotated;

Start described DC machine and obtain the sampled value of the current waveform of described DC machine, described current waveform comprises ripple component;

The sampled value of described current waveform is carried out to conversion process to obtain conversion process value; And

Described conversion process value is sued for peace in time to obtain summing value and according to DC machine described in described summing value control, made it rotate the number of turns needing.

Preferably, in said method, further comprise the step of the current location that records described automotive seat.

Preferably, in said method, described target location is the position of pre-stored user preference.

Of the present invention also have object to be to provide a kind of automotive seat control system, and it has advantages of that the cost of realization is low, accuracy is high.

Above-mentioned purpose of the present invention is realized by following technical proposal:

A kind of automotive seat control system, comprising:

DC machine, for driving described automotive seat;

Current detecting unit, for obtaining the sampled value of current waveform of described DC machine, described current waveform comprises ripple component;

Controller with described current detecting unit coupling, for determining according to the current location of described automotive seat and target location the number of turns that described DC machine need to be rotated, the sampled value of described current waveform is carried out to conversion process to obtain conversion process value, described conversion process value is sued for peace to obtain summing value in time, and determine the current location of described automotive seat according to the reference position of described summing value and described automotive seat.

Preferably, in above-mentioned automotive seat control system, described current detecting unit is the resistor in access described DC machine loop.

Preferably, in above-mentioned automotive seat control system, described controller comprises:

Signal conversion process unit, carries out conversion process to obtain conversion process value to the sampled value of described current waveform;

Sum unit, for suing for peace in time to obtain summing value to described conversion process value; And

Control signal generation unit, for generating the control signal to described DC machine according to summing value.

Preferably, in above-mentioned automotive seat control system, described target location is the position of pre-stored user preference, and described controller also comprises the memory device for storing described target location.

According to embodiments of the invention, the ripple component in employing current waveform is determined the number of turns of electric machine rotation, and this has saved the trouble that mounts multi-pole magnet-ring.On the other hand, because ripple component is taken from the current signal of measuring for monitoring motor operating state, therefore, without being equipped with special position signal detecting element, reduced cost.In addition, in an embodiment of the present invention, after current waveform is carried out to conversion process, sue for peace, can eliminate the amplitude of single ripple and the detection error that morphological differences causes.

From following detailed description by reference to the accompanying drawings, will make above and other objects of the present invention and advantage more completely clear.

Accompanying drawing explanation

Fig. 1 shows a kind of automotive seat control system with typical structure.

Fig. 2 is according to the diagram of circuit of the method for definite automotive seat position of one embodiment of the invention.

Fig. 3 shows typical DC machine current waveform figure.

Fig. 4 is according to the diagram of circuit of the control method of the automotive seat position of another embodiment of the present invention.

Fig. 5 is according to the schematic diagram of the automotive seat position regulating system of another embodiment of the present invention.

Fig. 6 is the structural representation of the controller in the automotive seat position regulating system shown in Fig. 5.

The specific embodiment

Below by being described with reference to the drawings, the specific embodiment sets forth the present invention.But it will be appreciated that, these specific embodiment are only exemplary, there is no restriction for spirit of the present invention and protection domain.

In this manual, " motion " word can be understood as the variation of object space state, and its form for example comprises translation, rotation or their combination etc." coupling " word should be understood to be included in the situation that directly transmits energy or signal between two unit, or indirectly transmit the situation of energy or signal through one or more Unit the 3rd, and alleged signal includes but not limited to the signal existing with the form of electricity, light and magnetic here.In addition, " comprise " and the term of " comprising " and so on represent except have in specification sheets and claims, have directly and the unit and step of clearly statement, technical scheme of the present invention is not got rid of yet and is had other unit of directly or clearly not explained and the situation of step.Moreover the term such as " first ", " second ", " the 3rd " and " the 4th " does not represent that unit or numerical value are to be only used as to distinguish each unit or numerical value in the order of the aspects such as time, space, size.

Also it is pointed out that as setting forth conveniently, in accompanying drawing, each unit might not be according to the scale of their reality, and in accompanying drawing, the size of each unit and the ratio between them do not form limiting the scope of the present invention.

Fig. 2 is according to the diagram of circuit of the method for definite automotive seat position of one embodiment of the invention.Although in actual applications, may adopt multiple DC machine to drive automotive seat to do the motion of various ways, but for simplicity, in the present embodiment only take seat position along a direction translation (dipping and heaving of for example seat or move forward and backward) as example, those skilled in the art will recognize that, for the mode of motion beyond translation, principle of the present invention is also suitable for.

As shown in Figure 2, in step 210, control setup (for example controller of automotive seat control system) obtains the current waveform signal of the DC machine that drives automotive seat from current detecting unit.In actual applications, current waveform signal can be to utilize A/D converter, and the series of measured values that sampling obtains at a certain time interval is also converted to digital value by observed reading.The measurement of electric current can adopt various ways, for example point platen press and the hall measurement method based on magnetic field effect based on resistor, and these methods all can be applicable to here.In addition, these observed readings can export control setup to by current detecting unit in real time, also can be buffered in current detecting unit and export in bulk control setup to.

Fig. 3 shows typical DC machine current waveform figure.

Referring to Fig. 3, in the time of smooth running, current waveform is not straight line, but the curve of cyclical fluctuations around baseline fluctuation, AC compounent (this AC compounent is also referred to as ripple component) is equivalent to superpose in DC component.This fluctuation is mainly to be determined by the following architectural feature of DC machine,, the commutator segment of engine commutator is with certain being spaced, and in the time rotating, brush contacts successively with each commutator segment, thereby makes to comprise around the ripple component of DC component fluctuation in electric current.Suppose that number of segment is k, there is following relationship in current ripples frequency f and motor speed n:

f＝k×n （1）

It is worthy of note, actual current signal may be with many " burrs ", they during with brush and commutator segment electrocorrosion situation and commutation before brush end relevant with the discharged condition of rear brush end, and only reflect that it is these envelop forms of being with " burr " waveforms that the ideal waveform contacting between brush and commutator segment generally can be considered as.Therefore when directly to digitized sampled value do integral operation with obtain integrated value time, this " burr " will cause integral error, thus impact position is determined the accuracy of result.Such as, although can adopt conventional filtering method (middle position value filtering method, first-order lag filter method, arithmetic average filter method and iir digital filter etc.) to carry out filtering interfering burr, but the present inventor finds after in-depth study, after adopting the following signal transformation method being proposed by contriver, can avoid this cumulative error.

Continue referring to Fig. 2, enter step 220 after step 210, the signal conversion process of ripple component being carried out will describe is below to remove disturbing signal.Sort signal conversion process can utilize special hardware circuit to realize, and also can utilize the computer program operating on universal computing device to realize.

As mentioned above, current waveform signal is generally multiple digital values of sampling at a certain time interval and obtaining, and in the present embodiment, can adopt following formula to carry out conversion process to these digital values:

$I_i^{\mathrm{Tran}}=\frac{\mathrm{Max}(I_i,I_{i-1...}{I}_{i-n+1})-I_i}{\mathrm{Max}(I_i,I_{i-1}...I_{i-n+1})-\mathrm{Min}(I_i,I_{i-1}...I_{i-n+1})}---\left(2\right)$

Here I _ibe i sampled value, I _i ^tranbe the transformed value of i sampled value, Max (I _i, I _i-1i _i-n+1) be the maxim (take i sampled value as benchmark) of nearest n digitalisation sampled value, Min (I _i, I _i-1i _i-n+1) be the minimum value (take i sampled value as benchmark) of nearest n digitalisation sampled value.

In step 230, according to following formula, transformed value is carried out to temporal summation subsequently:

$S=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{I}_i^{\mathrm{Tran}}\×\mathrm{\Δt}---\left(3\right)$

Here S is summing value, the quantity that m is sampled value, I _i ^tranbe the transformed value of i sampled value, Δ t is sampling time interval corresponding to above-mentioned digitized sampling value.

Enter subsequently step 240, determine its current location according to the reference position of summing value S and automotive seat.For example can utilize following formula to determine current location:

$N=\frac{S}{S_0}---\left(4\right)$

Here S ₀the summing value of transformed value while rotating one week for DC machine, the rotation number of turns that N is DC machine, L _cfor the current location of automotive seat, L _reffor the reference position of automotive seat, can be for example last time post exercise positions of automotive seat, Δ L is the translational movement that caused automotive seat position is enclosed in the every rotation one of DC machine.Here L while supposing that motor rotates along clockwise direction _refbe added with n × Δ L, and when rotating counterclockwise L _refl subtracts each other with n × Δ, but contrary hypothesis on result without substantial impact.

Then enter step 250, use current location L _cupgrade previous reference position L _reffor determining of next position.

Alternatively, in one embodiment of the invention, can periodicity or calibration reference position, aperiodicity ground.Particularly, can regularly or aperiodically make automotive seat enter end position (on this position, automotive seat cannot continue to move along the sense of motion identical with previous moment, the top of such as hoisting position, the bottom of lowering position and move forward and backward two ends of position etc.), and be updated to this end position with reference to position, make thus the integral error zero clearing accumulating above.

Fig. 4 is according to the diagram of circuit of the control method of the automotive seat position of another embodiment of the present invention.

As shown in Figure 4, in step 410, control setup (for example controller of automotive seat control system) obtains the target location that automotive seat need to arrive.Can make Linear-moving or enclose to rotate around the axis along multiple directions because automotive seat can be designed as, target location therefore may comprise multiple positional values (parameter).In one embodiment, this target location can adopt the form of one group of location parameter being inputted by user.Or alternatively, seat position parameter default settings when control setup can previously have been driven user is the target location that this user wishes, when user inputs after corresponding ID, control setup can be as index search to this corresponding group location parameter.

Enter subsequently step 420, control setup is from transferring the current location of automotive seat in memory device, namely residing position after the last automotive seat motion.Alternatively, can after each vehicles seat, be stored in memory device together with time stamp up-to-date position as current location.

Subsequently in step 430, control setup is determined the number of turns that DC machine need to be rotated and the direction of rotation according to the current location of automotive seat and target location.For example can utilize following formula to calculate the number of turns N of required rotation:

Wherein, L _cfor the current location of automotive seat, L _tarfor the target location of automotive seat, Δ L is the translational movement that caused automotive seat position is enclosed in the every rotation one of DC machine.Equally, although hypothesis motor L while rotating along clockwise direction here _cdeduct L _tar, and when rotating counterclockwise L _tardeduct L _c, but contrary hypothesis on result without substantial impact.

Then enter step 440, control setup starts DC machine and current detecting unit simultaneously.In the time of DC machine entry into service, current detecting unit drives the current waveform signal of the DC machine of automotive seat to control setup output.As mentioned above, current waveform signal can be obtain and the digitized observed reading of a series of sampling at a certain time interval.In the present embodiment, current detecting unit is cached the observed reading of current waveform signal and sends the observed reading of these buffer memorys to control setup every certain cycle (being called again below the transmission cycle).

Subsequently, in step 450, control setup carries out conversion process by the step 220 in execution graph 2 to the DC machine current waveform receiving from current detecting unit, and carries out summation operation by performing step 230 pairs of changing values, obtains thus current summing value.For example can calculate current summing value according to following formula:

$S\left(i\right)=S(i-1)+\underset{j=1}{\overset{m}{\mathrm{\Σ}}}{I}_{i,j}^{\mathrm{Tran}}\×\mathrm{\Δt}---\left(7\right)$

Here S (i) and S (i-1) are respectively i summing value that sends when end cycle and calculate when (i-1) individual transmission end cycle, and m is the quantity of the sampled value in i transmission cycle, I _ij ^tranbe the transformed value of j sampled value in i transmission cycle, Δ t is and j the sampling time interval that sampled value is corresponding in i transmission cycle.

Then enter step step 460, control setup judges whether DC machine has rotated the number of turns definite in step 430.For example can utilize following condition as basis for estimation:

S(i)≥N×S ₀ （8）

Here S ₀the summing value of current waveform while rotating one week for DC machine, N is the number of turns of the required rotation of DC machine.

If judged result is true, enter step 470, more previous current location in new memory of target location for control setup; Otherwise return to step 450.

Fig. 5 is according to the schematic diagram of the automotive seat position regulating system of another embodiment of the present invention.

As shown in Figure 5, comprise DC machine 510, current detecting unit 520, controller 530 and the pwm unit 540 for driving automotive seat according to the automotive seat control system 50 of the present embodiment.

Current detecting unit 520 is for detection of the electric current in DC machine 510 loops, place.In the present embodiment, current detecting is based on dividing potential drop mode, for this reason, and the A/D converter that current detecting unit 520 comprises voltage grading resistor and the voltage at voltage grading resistor two ends is sampled.Current detecting unit 520 can also comprise high-speed cache, and the sampled signal that A/D converter obtains or observed reading can temporarily be kept in this high-speed cache and periodically send to controller 530.

Controller 530 is recently controlled the running of DC machine 510 by the duty of controlling pwm unit 540 output signals, thereby automotive seat are adjusted to desired position.For example, controller 530 can determine that DC machine 510 needs the number of turns of rotating according to the current location of automotive seat and target location, the current waveform signal that current detecting unit 520 is sent carries out conversion process and transformed value is carried out to summation operation, and controls the running of DC machine 510 according to summing value.

In addition the current signal that, controller 530 can also detect according to current detecting unit 520 judges the running state (such as level of torque, whether occur stall etc.) of DC machine 510.

It is worthy of note, although automotive seat only comprise a DC machine in the above-described embodiments, as long as system architecture is made to the situation that corresponding change can be suitable for many motors.For example, in the situation that adopting a controller, for configuring independent current detecting unit, each motor is connected with pwm unit and with controller, thereby make controller according to the current waveform of each motor, control independently each DC machine by pwm unit separately.In addition, in the present embodiment, the actuating unit of controlling DC machine is pwm unit, but also can adopt the mechanism of other type, for example, include but not limited to relay etc.

Fig. 6 is the structural representation of the controller in the automotive seat position regulating system shown in Fig. 5.

As shown in Figure 6, controller 530 comprises communication interface 531, signal conversion process unit 532, sum unit 533, memory device 534 and control signal generation unit 535.

Communication interface 531 is responsible for and the communicating by letter of unit that is positioned at controller 530 outsides.Particularly, communication interface 531 communicates with the current detecting unit 520 in Fig. 5, with received current waveform signal or observed reading and send the instruction that starting current detecting unit 520 moves.Pwm unit 540 in itself and Fig. 5 communicates, and sends to pwm unit 540 with the control command that control signal generation unit 535 is generated.In addition, communication interface 531 also such as, is communicated by letter with user input device (touch-screen, button etc.), for receiving data and the instruction of user's input.

Signal conversion process unit 532 is coupled with communication interface 531, and its current waveform signal that communication interface 531 is received carries out as above by the conversion process as described in Fig. 2.Sum unit 533 is coupled with signal conversion process unit 532 and control signal generation unit 534, and it is sued for peace and export operation result to control signal generation unit 535 current waveform signal after conversion process.Sum unit 533 for example can adopt the mode of describing by embodiment described in Fig. 4 to complete above.

Memory device 534 is coupled with control signal generation unit 535 and sum unit 533, the seat target location that it can stored user profile and the current location of seat.

Control signal generation unit 535 is coupled with communication interface 531, signal conversion process unit 532, sum unit 533 and memory device 534, the operation that it is responsible for other unit in control and tuning controller 50 on the one hand, also generates the control signal to DC machine 510 on the other hand.For example, control signal generation unit 535 can be for example according to the mode by description embodiment illustrated in fig. 4 above, the number of turns of DC machine 510 required rotations is determined in the target location of user preference of the target location receiving according to communication interface 531 or storage in memory device 534, the summed result of utilizing sum unit 533 to export determines whether DC machine 510 turns to the required number of turns or whether automotive seat arrive desired position, if arrival desired position, its generation makes pwm unit 540 stop the instruction of output signal, otherwise generate the instruction that makes pwm unit 540 outputs there is the signal of certain dutycycle.

It is worthy of note, in the embodiment shown in fig. 6, coupling respectively between other unit of control signal generation unit 535 and controller inside, but also can by bus mode, above-mentioned communication interface 531, signal conversion process unit 532, sum unit 533, memory device 534 and control signal generation unit 535 be coupled in controller inside.In addition, although signal conversion process unit 532, sum unit 533 and the control signal generation unit 535 in above-mentioned controller can be realized with special hardware circuit respectively, at least part of unit in them also can be realized by the mode of general purpose microprocessor+software module.

Owing to can not deviating under the spirit of essential characteristic of the present invention, implement the present invention with various forms, therefore present embodiment is illustrative and not restrictive, because scope of the present invention is defined by claims, rather than defined by specification sheets, therefore fall into all changes in border and the boundary of claim, or the equivalent of this claim border and boundary thereby forgiven by claim.

Claims (14)

1. a method for definite automotive seat position, described automotive seat are driven by DC machine, it is characterized in that, comprise the following steps:

Obtain the sampled value of the current waveform of described DC machine, described current waveform comprises ripple component;

The sampled value of described current waveform is carried out to conversion process to obtain conversion process value;

Described conversion process value is sued for peace to obtain summing value in time; And

Determine the current location of described automotive seat according to the reference position of described summing value and described automotive seat.

2. the method for claim 1, wherein according to following manner, the sampled value of described current waveform is carried out to conversion process:

$I_i^{\mathrm{Tran}}=\frac{\mathrm{Max}(I_i,I_{i-1...}{I}_{i-n+1})-I_i}{\mathrm{Max}(I_i,I_{i-1}...I_{i-n+1})-\mathrm{Min}(I_i,I_{i-1}...I_{i-n+1})}$

Here I _ibe i sampled value, I _i ^tranbe the transformed value of i sampled value, Max (I _i, I _i-1i _i-n+1) be the maxim of nearest n digitalisation sampled value, Min (I _i, I _i-1i _i-n+1) be the minimum value of nearest n digitalisation sampled value.

3. the voltage the method for claim 1, wherein accessing on the resistor in described DC machine loop by measurement obtains described current waveform.

4. the method for claim 1, wherein described reference position is last time post exercise positions of described automotive seat.

5. the end position that the method for claim 1, wherein described reference position is described automotive seat, and periodicity or the described reference position of calibration, aperiodicity ground.

6. a control method for automotive seat position, described automotive seat are driven by DC machine, it is characterized in that, comprise the following steps:

Determine according to the current location of described automotive seat and target location the number of turns that described DC machine need to be rotated;

Start described DC machine and obtain the sampled value of the current waveform of described DC machine, described current waveform comprises ripple component;

The sampled value of described current waveform is carried out to conversion process to obtain conversion process value; And

Described conversion process value is sued for peace in time to obtain summing value and according to DC machine described in described summing value control, made it rotate the number of turns needing.

7. method as claimed in claim 6, further comprises the step of the current location that records described automotive seat.

8. method as claimed in claim 6, wherein, according to following manner, the sampled value of described current waveform is carried out to conversion process:

$I_i^{\mathrm{Tran}}=\frac{\mathrm{Max}(I_i,I_{i-1...}{I}_{i-n+1})-I_i}{\mathrm{Max}(I_i,I_{i-1}...I_{i-n+1})-\mathrm{Min}(I_i,I_{i-1}...I_{i-n+1})}$

Here I _ibe i sampled value, I _i ^tranbe the transformed value of i sampled value, Max (I _i, I _i-1i _i-n+1) be the maxim of nearest n digitalisation sampled value, Min (I _i, I _i-1i _i-n+1) be the minimum value of nearest n digitalisation sampled value.

9. method as claimed in claim 6, wherein, described target location is the position of pre-stored user preference.

10. an automotive seat control system, is characterized in that, comprising:

DC machine, for driving described automotive seat;

Current detecting unit, for obtaining the sampled value of current waveform of described DC machine, described current waveform comprises ripple component;

Controller with described current detecting unit coupling, for determining according to the current location of described automotive seat and target location the number of turns that described DC machine need to be rotated, the sampled value of described current waveform is carried out to conversion process to obtain conversion process value, described conversion process value is sued for peace to obtain summing value in time, and determine the current location of described automotive seat according to the reference position of described summing value and described automotive seat.

11. automotive seat control systems as claimed in claim 10, wherein, described current detecting unit is the resistor in access described DC machine loop.

12. automotive seat control systems as claimed in claim 10, wherein, described controller comprises:

Signal conversion process unit, carries out conversion process to obtain conversion process value to the sampled value of described current waveform;

Sum unit, for suing for peace in time to obtain summing value to described conversion process value; And

Control signal generation unit, for generating the control signal to described DC machine according to summing value.

13. automotive seat control systems as claimed in claim 12, wherein, described signal conversion process unit carries out conversion process according to following manner to the sampled value of described current waveform:

$I_i^{\mathrm{Tran}}=\frac{\mathrm{Max}(I_i,I_{i-1...}{I}_{i-n+1})-I_i}{\mathrm{Max}(I_i,I_{i-1}...I_{i-n+1})-\mathrm{Min}(I_i,I_{i-1}...I_{i-n+1})}$

Here I _ibe i sampled value, I _i ^tranbe the transformed value of i sampled value, Max (I _i, I _i-1i _i-n+1) be the maxim of nearest n digitalisation sampled value, Min (I _i, I _i-1i _i-n+1) be the minimum value of nearest n digitalisation sampled value.

14. automotive seat control systems as claimed in claim 10, wherein, described target location is the position of pre-stored user preference, and described controller also comprises the memory device for storing described target location.

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