FR2800213A1 - DEVICE FOR IMPLEMENTING SEVERAL STEP MOTORS WITH AN OPERATING VOLTAGE LOWER THAN THEIR COMMON SUPPLY VOLTAGE - Google Patents

Abstract

Device for implementing several stepper motors having operating voltages lower than a common supply voltage and windings supplied by semiconductor power switches, controlled by advance step sequences. A microcomputer (C), taking into account the grouping (GR1, GR2) of the motors in series and / or in parallel (M11-M1n; M21-M2m), the associated step sequences in the memory (SP) and the impedances of the motor windings (Ph1-Ph4), performs an impedance compensation in the groups (GR1, GR2) to maintain their supply voltage by an additional synchronous control of motors not to be switched with a holding step sequence .

Description

STATE OF THE ART The present invention relates to a device for

  implementation of several stepper motors of an installation

  tion, having operating voltages lower than a common supply voltage of stepping motors whose

  windings are powered by semi switches

  power stage conductors, and these are controlled by step sequences, to switch the motors

step by step.

  Stepper motors are increasingly used

  to control actuators such as valves, the air shutter or the like in

  motor vehicles. Passenger cars and cars

  Utility vehicles use various supply voltages

  tation, that is to say those provided by the on-board networks

  which are for example 12V and 24V. As the demand for stepper motors for passenger cars is very high, stepper motors powered by 12V are mass produced products more advantageous than motors

  step by step supplied with 24V for commercial vehicles.

  The stepper motors are controlled by a

  step sequence; in this sequence, for all the windings-

  elements of a stepping motor, state "1" indicates

  the power supply and the "O" state the non-powered state of the reels

  engine elements. To switch a stepping motor, it is supplied with a step sequence, that is to say a variable step sequence or advance step sequence. Following the step sequence can cyclically set the direction of motor rotation

  step by step, that is to say the movement of advance or retreat.

  A special feature of the stepper motor is that for an

  continuous statement, i.e. an order with the same segment

  step sequence, i.e. a sustain step sequence,

  the engine remains stationary and does not switch further.

  If you operate, for example, 12V stepper motors with a supply voltage of 24V,

  an intermediate resistance is required for each step sequence

  diary dimensioned according to the motor windings

  supplied, to achieve the desired voltage division.

  This dimensioning rule applies to all cases in which the stepping motors must receive a voltage

  operating from a supply voltage

  mune greater than the operating voltage of the stepper motor. Voltage converters can also be used to reduce a high supply voltage to a lower voltage for stepper motors. If such an installation comprises several stepping motors which have to switch according to different modes, the power of the voltage converter must correspond so that the converted operating voltage does not depend too strongly on

load.

  Both types of operation have drawbacks because they all require the implementation of

  considerable resources for voltage conversion.

  The present invention aims to develop a device corresponding to the type defined above, comprising

  several stepper motors in an installation, without ne-

  stop implementing additional means to

  green the voltage, and which makes it possible to use a supply voltage greater than the operating voltage of the stepping motors, without however considerably limiting the operating conditions of the stepping motors of

the installation.

  To this end, the invention relates to a device of the type defined above, characterized in that

  * the supply voltage (for example 24V, 36V) is sub-

  divided into at least two ranges of operating voltages

  ment, * for each range of operating voltages, a group of stepping motors is associated with a corresponding supply voltage (for example 12V, 12V and 24V),

  * in each group the series assemblies formed by the reels

  semiconductor switches of the stepper motor power stages are connected in parallel, * the groups of the series circuits are connected in series and connected to the supply voltage,

  * in a memory of an order the windings are recorded-

  motor components last supplied and belonging to all stepper motors, i.e. the last sequence of steps executed, and * a microcomputer, taking into account the step sequences

  associated in the memory and impedances of the windings

  motor components corresponding to the operating cases, controls the stepping motors whose switching must be continued with a variable advance step sequence, and by an additional synchronous control of stepping motors which must no longer be switched, with a sequence of

  no hold remaining constant, compensates

  impedance in the groups so that for each operating case, the overall group impedances are in a ratio corresponding to the ratio of the supply voltages (for example 12V: 12V or 12V: 24V)

groups of stepper motors.

  By dividing the stepper motors of the installation into groups and with the series mounting of the groups, by an additional control of the stepper motors with a holding step sequence, the stepper motors which must not switch are used to compensate

  impedance, to ensure that in each case

  The supply voltage is distributed among the operating voltages associated with the stepper motor groups. Stepper motors that should not switch

  thus play the role of intermediate resistances or

  voltage boosters used so far in so-

  known versions. The overall impedances of the groups can perfectly vary from one operating mode to another,

  but it is essential that the ratio of the total impedances

  the groups does not vary and always remains in the report

  wearing divided operating voltage ranges for

supply voltage.

  A corresponding function is provided by the

  memory and the microprocessor of the control. Memory con-

  keeps track of all the step sequences last executed by all the stepper motors in the installation. The desired operating mode is applied as an input condition to the microprocessor. The microprocessor thus recognizes the stepping motors which must switch and the direction of their rotation.

  tation; it controls the sequence of switching steps cor-

  corresponding taking into account the step sequences last applied and saved in the memory for such stepper motors. The microprocessor further recognizes the situation of the stepper motors in the groups and their control power, so that the switching step sequences provided by the microprocessor can also

  be applied to the desired stepper motors.

  In order to respect the voltage division in the stepper motor groups, the microcomputer forces an additional synchronous control of stepper motors which must not be switched, with a sustaining step sequence, compensation of the impedance in groups in which the total impedance of the windings of

  motor supplied differs from the predetermined ratio by the voltages

  groups. It is important to always adapt to the groups in which you need to

  supply the majority of motor windings with

  quences of steps ahead. So by taking into account

  step sequences stored in memory for all modes

  step by step and entry conditions, the microprocessor

  seur can select the synchronous command so that the group operating voltages are respected for

  each application. The control of the stepper motors concerned

  born must be done simultaneously, that is to say at the same rate. For impedance compensation, the microcomputer must also take into account the impedances of the motor windings in the groups. If for example a group of stepping motors supplied with 24V and a group of stepping motors supplied with 12V, are switched in series at a supply voltage of 36V, and if all the stepping motors have windings of same impedance, then a stepper motor of the group at 24V controlled with two motor windings according to the sequence of steps of advance can be compensated by a stepper motor of the group 12V if two stepper motors of the 12V group with two windings. On the other hand, with a stepper motor of the 24V group it is possible to compensate two stepper motors of the 12V group supplied with

a sequence of steps ahead.

  A considerable simplification is achieved in the installation and control of the stepper motors if the impedances of the motor windings in the groups are

  the same and have a relationship between them corresponding to the

  wearing of the operating voltages of the groups, and if for each operating case, independently of the control with a sequence of steps of advancing or holding, the number of motor windings supplied in the groups is the same each time. We can then give up taking into account in addition to the impedance of the motor windings as it

  in general should be done in the design of the

previously described.

  For the specific case of using 12V stepper motors in an installation receiving a supply voltage of 24V, the mounting and control are such that all the stepping motors in the installation have

  the same number of motor windings with the same impedance

  dance, the operating voltage of the stepper motors

  corresponds to half of the supply voltage, the mo-

  tutors are divided into two groups, and for each

  operating case, we will have in both groups, a name-

  Bre identical times of powered motor windings, independently of the control with a sequence of advance steps or a sequence of holding steps. This is generally true if the operating voltage of the stepper motors

  used corresponds to half of the supply voltage.

  According to one embodiment, the operating cases are characterized in that the input conditions associated with the stepping motors provide the microprocessor with the desired operating case, and the microprocessor taking into account the corresponding content of the memory and

  the impedance of the windings of the stepper motors of the groups

  pes, sets the step sequence in advance for stepper motors

not that you have to switch.

  To ensure that the contents of the memory always correspond to the most recent state, it is intended that for each

  that in case of operation, the content of the memory is

  defined according to the sequences of steps in advance and of

  hold applied to stepper motors.

  According to an embodiment for the control and the supply, the microcomputer transmits the sequence of steps of advance and of maintenance by switching stages to

  from the command lines to the command inputs of the

  semiconductor power mutators.

  The control means can be reduced if the windings of the stepping motors are supplied by a

matrix control.

  We can also develop the invention in this

  that in the area with a range of operating voltages-

  with stepping motors with operating voltage

  reduced, subgroups of integrated stepper motors are formed

  in the same way as the stepper motors of the groups in the command and impedance compensation program

of the microcomputer.

  An advantageous development is characterized in that by an additional brief supply of the stepping motors of a group or a sub-group, for the other group or sub-group the operating voltage is increased and thus

  the couple. This means can also be taken in an installation.

  lation to several groups and several subgroups, for

  be applied successively to groups and subgroups.

  An optimal variation possibility in the case of operation corresponds to a practically the same number of stepping motors in the groups and the sub-groups and in that the distribution of the stepping motors between the groups is done taking into account the operating case to be able to power the stepping motors in each operating case, as much as possible in practically all

groups and subgroups.

  The present invention will be described below with the aid of exemplary embodiments shown diagrammatically in the appended drawings in which: * FIG. 1 shows a circuit with two groups of stepping motors supplied by a uniform operating voltage

  that, corresponding to half of the supply voltage

  tation, * Figure 2 shows a device similar to that of Figure 1 but with a matrix drive of the stepper motors, * Figure 3 shows a device with an increase

  brief torque of a stepper motor controlled by a

quence step by step in advance.

  According to FIG. 1, in the characteristic case of a 12V or 24V on-board network of a motor vehicle, the (n) Mll-Mln stepper motors form a first group

  GR1 and the (m) stepper motors M21 ... M2m constitute a se-

  cond GR2 group substantially the same size. All the stepping motors of the two groups GR1, GR2 not only have an operating voltage Um corresponding to half the

  Ubatt pre-supply voltage, but also windings

  Phl, Ph2, Ph3 and Ph4 elements with the same impedance and the same number of four windings. The Phl-Ph4 motor windings of all the stepper motors in the installation are

  connected in series with the semi-power stages

  conductors Tl, T2, T3 and T4 and can be supplied by

  these stages when the command input is ordered. The com-

  T1-T4 power stage semiconductor mutators may

  can have individual sl-s4 command lines for

  that under the maximum conditions, we have an association

  individual stepper motors and microcalcula-

  HtC value of the ST command, with a number of (4xn) + (4xm) command lines. The control potential will be applied by individual switching stages Sgl and Sg2 to

  each group. These floors have nx4 or mx4 interrup-

  teurs. The control of the switch groups Sgl, Sg2 is ensured by the microcomputer pC whose input lines el ... e (n + m) receive operating condition information. At each stepper motor

  the installation we can associate any number of li-

  entry genes. The input line for example el can also

  be associated with several stepper motors of a group or of the two groups if these stepper motors are to be supplied in common, in the same way. The stepper motors are then also controlled by the common sl-s4 control lines. The pC microcomputer knows the position of all the stepper motors in these groups. The ST command

  also has a memory SP in which are stored

  the step sequences, last supplied to the

  step by step (regardless of whether it is a sequence of steps to move forward or to stay still). This is obtained in a simple manner in that the advance or maintenance sequences supplied by the microcomputer pC from the input conditions, that is to say from the operating case, are also supplied to the memory SP. The step sequences

  can also set the direction of rotation of the mo-

step by step orderer so ordered.

  In the embodiment of FIG. 1, for the impedance compensation, in order to respect the divider voltage Um between the operating voltage of the stepping motors of the groups GR1, GR2 it suffices that in each

  group GR1, GR2, for each operating state,

  lie the same number of Phl-Ph4 motor windings. If that

  is already the case due to the mid-step sequence

  pC croprocessor, it is not necessary to carry out an impedance compensation because it is supposed that the impedances of all the windings Phl-Ph4 of all the stepper motors Mll-Mln and M21-M2m are the same. If not, using

  hold step sequences, compensate for

  impedance on stepping motors which are not to be switched in the group, with at least one sequence of switching steps so that in this group, the corresponding number of motor windings are supplied. This compensation

  impedance must occur in each operating mode-

  if groups GR1, GR2 are switched differently

  rent, which is to be taken into account already in the last sequence of steps recorded in the memory SP and means as indicated by the clock TG, that it is a movement

  synchronous, that is to say that we switch at the same rate.

  It is easy to see that the layout can also have more than two groups if the supply voltage Ubatt is subdivided into several voltages of

  operation; these operating voltages must cor-

  respond to the operating voltages of different stepper motors. In addition, groups connected in series can be directly divided into sub-groups. For example, a group of 24V step sequences can be subdivided into two subgroups comprising 12V stepper motors. These

  subgroups connected in series are then connected in parallel-

  lele on 24V stepper motors of the associated group. The com-

  subgroups and impedance compensation are controlled in the same way as in groups with the pC microcomputer, taking into account the content of the memory and the input conditions of the lines entrance el ... e (n + m). For impedance compensation, in each operating case, the ratio of the overall impedance of the motor windings supplied in

  groups GR1, GR2 according to the ratio of the operating voltages

  groups. In the exemplary embodiment according to FIG. 1, this means a 1: 1 ratio. This impedance compensation is obtained if in each group GR1, GR2 we

  supplies the same number of windings Phl, Ph4.

  The overall impedances in groups GR1, GR2 can vary from one operating case to another, but these impedances must always be equal. The same procedure also applies to more than two groups of stepper motors with different operating voltages if the

  sum of the divider voltages Um of the groups connected in se-

  rie corresponds to the Ubatt supply voltage. For some

  different impedances of the Phl-Ph4 windings, this com-

  thinking of impedances is even simpler if the impedances

  dances of the groups' stepper motors are in a ratio which corresponds to that of the divider voltages Um. If not, the pC microcomputer must compensate for this difference in impedance by a corresponding number

  of powered Phl-Ph4 motor windings, which must be

  think like it has already been described.

  According to Figure 2, the control means for

  switch can be reduced in that a matrix command

  it is chosen for stepper motors. By these lines

  sl-s4, it is controlled by semi-switches

  T1-T4 output stage conductors, the windings of all Mll-Mln or M21-M2m stepper motors, of a group

  GR1, GR2 that is to say, the groups are selected. The selection

  tion of the stepper motors of a group is ensured by individual switches by motor mll-mln or m21-m2m which are nested in the supply voltage line of the windings Phl-Ph4 of the group GR1, GR2. If for example the switch mll is closed, then only the stepper motor Mll

  of the GR1 group will be supplied, if the semi-

  T1-T4 output conductors associated with group GR1 are com-

  mandated, while the M12-Mln stepper motors remain

  cut off from the power. Impedance compensation is also performed

  if by the matrix drive of the stepper motors.

  Finally, a detail of an installation with only two stepping motors Mll and M21 connected in series according to FIG. 3, shows a possibility of ensuring by command

  brief of a GR1 group M1 stepper motor by providing it-

  sant the power supply for all phases Phl-Ph4 with a holding step model 1111, a brief increase in the division voltage Uh, to give the stepping motor M21 of the other group GR2, the step sequence d 'advance 1010 with higher torque. When all the stepper motors

  Mll ... M21 have the same impedance, so by feeding the

  Phl motor bearings, Ph3 of the M21 stepper motor with the advance step sequence 1010, and all the Phl-Ph4 motor windings of the Mll stepper motor with a holding step sequence 1111, there will be a rise voltage of the group GR2 and thus of the stepping motor M21 which is reached for Uh = 16V; this level leads to higher torque for the

M21 stepper motor.

he

Claims (10)

R E V E N D I C A T I ON S   1) Device for implementing several stepping motors of an installation, having operating voltages lower than a common supply voltage of stepping motors, the windings of which are supplied by semiconductor switches of power stages, and these   are controlled by step sequences in advance, for commu-   ter stepping motors, characterized in that * the supply voltage (Ubatt, for example 24V, 36V) is subdivided into at least two ranges of operating voltages, * each range of operating voltages is associated   a group (GR1, GR2) of stepping motors (Mll-Mln; M21-   M2m), with a corresponding supply voltage (for example 12V, 12V and 24V), * in each group (GR1, GR2) the series connections formed by the windings (Phl, Ph2, Ph3, Ph4) and semi- switches power stage conductors (Ti, T2, T3, T4) of the stepping motor (Mll-Mln or M21-M2m), are connected in parallel, * the groups (GR1, GR2) of the series circuits are connected in series and we connect them to the supply voltage (Ubatt), * in a memory (SP) of a command (ST) we record the motor windings (Phl, Ph2, Ph3, Ph4) supplied last and belonging to all the stepping motors (Mll-Mln) and (M21-M2m), i.e. the step sequences executed last, and e a microcomputer (pC), taking account of the associated step sequences in the memory (SP) and of the impedances of the motor windings (Phl-Ph4) corresponding to the operating cases, controls the stepping motors whose switching must be continued with c a sequence of steps   variable advance, and by an additional synchronous command   of stepper motors which must no longer be switched, with a holding step sequence remaining constant, performs impedance compensation in the groups (GR1, GR2), so that for each operating case the overall impedances groups (GR1, GR2) are in a ratio corresponding to the ratio of the supply voltages (for example 12V: 12V or 12V: 24V) groups (GR1, GR2) of stepping motors (Mll-Mln; M21-M2m ). 2) Device according to claim 1, characterized in that * the impedances of the windings (Phl, Ph2, Ph3, Ph4) are equal in the groups (GR1, GR2) and have between them a   ratio which corresponds to the ratio of operating voltages   operation of the groups (GR1, GR2), and * for each operating case, independently of the control with a step sequence of advance or maintenance, the number of motor windings supplied (Phl, Ph2, Ph3, Ph4) in the groups (GR1, GR2) is the same each time. 3) Device according to claim 1 or 2, characterized in that * all the stepping motors (Mll-Mln and M21-M2m) of the installation have the same number of windings (Phl, Ph2, Ph3, Ph4) of the same impedance, * the operating voltage (for example 12V) of the stepping motors (Mll-Mln, M21-M2m) corresponds to the supply half-voltage (Ubatt = 24V), * the stepping motors ( Mll-Mln or M21-M2m) are divided into two groups (GR1, GR2), and * for each operating case, in the two groups (GR1, GR2), there is each time the same number   of powered windings (Phl, Ph2, Ph3, Ph4), independently   command with a step sequence or a sustain step sequence.   4) Device according to one of claims 1 to 3,   characterized in that the microprocessor (pC) receives, as desired operating case, the input conditions associated with the stepping motors (Mll-Mln; M21-M2m), such as for example the continuation of the switching in the direct direction or the opposite direction, and the microprocessor (pC), taking into account the associated memory content and the impedances of the windings of the stepping motors in the groups (GR1, GR2), fixes the sequence of   no advance for stepper motors which must be switched.   5) Device according to any one of claims 1   to 4, characterized in that for each operating case, the content of the memory   is changed according to the steps of advance and main-   yours supplied to stepping motors (Mll-Mln; M21-M2m).   6) Device according to any one of claims 1   to 5, characterized in that the microcomputer (pC) transmits the advance and maintenance step sequences by switching stages (Sgl, Sg2) to control lines (sl-s4) to the inputs of   control of semiconductor power stage switches sance (T1-T4).   7) Device according to any one of claims 1   6, characterized in that the motor windings (Phl, Ph2, Ph3, Ph4) of the stepping motors (Mll-Mln; M21-M2m) are supplied by a matrix control.   8) Device according to any one of claims 1   to 7, characterized in that in the area of operating voltage range (for example 24V) having stepper motors supplied by a reduced supply voltage (for example 12V),   subgroups of integrated stepper motors of the same ma-   negates that the group stepper motors (GR1, GR2) in the command and impedance compensation program of the microprocessor (pC).   9) Device according to any one of claims 1   to 8, characterized in that by a brief additional supply of the stepper motors of a group (for example GR1) or of a sub-group, one   may cause an increase in operating voltage   and thus of the couple for the other group (for example GR2) or subgroup.   10) Device according to any one of claims 1   to 9, characterized in that * the number of stepping motors (Mtl-Mln; M21M2m) is practically the same in the groups (GR1, GR2) as in the sub-groups, and * the distribution of the stepping motors (Mll-Mln; M21-M2m) between the groups (GR1, GR2) is done taking into account the operating cases, in order to be able to supply as many stepping motors as possible in each operating case   not in all groups (GR1, GR2) and all sub- groups.