Stationary adjustment with actuation of

Abstract

The invention relates to a stationary control with actuation variable activation. In order to specify a method for the static adjustment of a drive body (JA) on which a frictional force (Fr) acts, an activation actuation variable (uakt) is specified, by means of which a controlled reduction of undesirably stored potential energy can be achieved, said activation actuation variable changing a set actuation variable (us) that does not overcome the frictional force (Fr) into a slack actuation variable (uent), the activation actuation variable (uadd) is activated by the actuator (A) and the relaxation actuation variable (uent) is converted by the actuator (A) into a relaxation drive force (Fint) acting on the drive body (JA), the activation actuation variable (uadd) being specified in such a way that the relaxation drive force (Fint) at least temporarily overcomes a friction force (Fr) acting on the drive body (JA) during the stationary adjustment.

Description

Technical Field

[0001] The invention relates to a method for stationary control of a drive body, wherein friction forces act on the drive body, wherein a set operating variable is determined and converted by an actuator into a drive force acting on the drive body in order to bring the drive body to a standstill and / or to keep the drive body stationary. The invention also relates to a drive system comprising a drive body, a control unit and an actuator. Background Art

[0002] The important and common task of modern drive technology is the regulation of speed and position. The terms "speed" and "position" can represent linear speed, angular velocity, rotational speed, trajectory speed and position corresponding to speed. In the following embodiments, the above examples are referred to using the general terms "speed" and "position", wherein speed and position are understood as the speed and position of a (mechanical) subject, which can be a component of a mechanical monomer or multi-body system. Within the scope of this patent application, a monomer or multi-body system is understood as a mechanical system of at least one mechanical monomer, wherein a plurality of mechanical monomers can be mechanically coupled to each other (for example, through a hinge or force element, such as a spring or damper) and are affected by a force (for example, a force generated by an actuator or a servo motor or an electric motor). A multi-body system for generating the mentioned force expanded with an actuator is referred to as a drive system. Examples of drive systems with speeds to be regulated and / or positions to be regulated can include internal combustion engines (whose crankshaft speed is adjustable), motors (whose rotor speed or rotor position is adjustable) or transmission systems with multiple masses / inertias that are usually driven by a machine (whose angular velocity is adjustable).

[0003] Depending on the application, different requirements are associated with the task of "speed and / or position control of a drive system". Examples include shortening the response time, reducing the control energy used, suppressing vibrations and / or oscillations, and increasing the control dynamics and accuracy. In combination with the always given framework conditions of "small overall size" and "low costs", the above requirements constantly lead to new research problems in drive technology, which are also reflected in the known prior art.

[0004] Thus, EP 3 958 446 A1 teaches a linear motor system having a guide rail, a plurality of electromagnets distributed along the guide rail, and at least one transport unit which is guided by the guide rail and can be moved along the guide rail and can be pivoted to improve position adjustment.

[0005] DE 10 2019 133 025 A1 discloses a method for position control of an electromechanical assisted steering system, in which controller parameters are adjusted based on a frequency response identified during operation.

[0006] EP 0473914 A2 furthermore shows a system for position control of a control box in a motor vehicle, wherein a target value to be adjusted is influenced by a guide shaper in order to improve the dynamics of the system under different operating conditions, the guide shaper in turn being dependent on an estimated value of the position to be adjusted.

[0007] However, a situation that is only insufficiently discussed in the cited prior art is the unintentional storage of potential energy. Specifically, in different drive systems, the storage of potential energy can occur during the positioning process, which can be caused by various reasons, but in practice is usually caused by friction effects (e.g. bearing friction, friction effects between coupled loads). The potential energy stored in the drive system can manifest itself in different ways, but in particular by stresses that remain at rest, for example as retained stresses of mechanical springs or mechanical axes of a multi-body system driven in the drive system, or also as retained tilting of a body with an uncontrollable degree of freedom, for example in a linear drive system as a tilting of the transport unit in a spatial direction, for example around an axis of rotation, which spatial direction is different from the direction of movement along which the transport unit can be moved in an adjustable manner, which axis of rotation cannot be controlled by an adjustment unit for adjusting the movement of the transport unit.

[0008] An important example of a type of drive system in which the undesirable storage of potential energy usually occurs is a drive system having a drive body and at least one coupling body that is mechanically coupled to the drive body mostly through a mechanical shaft, and static friction acts on at least one coupling body. In this drive system, the position regulator is repeatedly used to obtain the operating parameter for adjusting the position of the drive body or setting it to the target position, and the operating parameter is converted into a driving force acting on the drive body by an actuator. In practice, the following situation may occur in this two-body system, that is, the coupling body ends its movement at the end of the positioning process, and stops before the drive body reaches the target position preset for it and therefore still moves. The important reason for this is the driving force required by the position regulator and acting on the drive body that is reduced when the positioning process is close to the end. The reduced driving force also leads to a reduced coupling force transmitted by the mechanical coupling and acting on the coupling body. If the coupling force acting on the coupling body is less than the friction force acting on the coupling body, the friction force hinders the coupling body, so that the coupling body is braked and finally stops. If the coupling body is then fixed and the drive body is still moved, in particular to reach a target position provided for it, a distortion of the mechanical coupling between the drive body and the coupling body may occur for obvious reasons. According to Hooke's law, potential energy is stored in the mechanical coupling.

[0009] For example, if the position of the upper side of the friction-prone body is positioned, the lower side opposite the upper side is hindered by friction (for example by static friction or sliding friction or rolling friction or rolling friction), the upper side and the lower side move relative to each other during positioning, and the single body itself twists, then the storage of potential energy can also occur on a single friction-prone body.

[0010] If, starting from rest, a renewed movement is started with stored potential energy, it is generally the case that the stored potential energy decreases after the movement of the given body has been resumed. In the above-mentioned example of a two-body system, as soon as the coupling body leaves the friction band determined by the acting friction force, the existing distortion of the mechanical coupling is generally resolved abruptly when the movement is resumed, which can lead to undesirable oscillations and vibrations of the drive body and / or the coupling body. Therefore, it is applicable for various reasons to avoid unnecessary and uncontrollable storage of potential energy in the drive system, whether due to increased component loads, reduced control accuracy or increased control energy consumption.

[0011] The known prior art does not mention in detail the potential energy stored in the drive system and therefore does not provide any method for counteracting oscillations caused in particular by a reduction in potential energy. Summary of the invention

[0012] It is therefore an object of the present invention to provide a method for operating a drive system which allows a controlled reduction of potential energy which is undesirably stored when a single-body or multi-body system is shut down.

[0013] This object is achieved by the features of the independent claims. Specifically, the independent claims of the above-mentioned method are provided for determining a set operating variable (which alone leads to a driving force that does not overcome the friction force) for a drive body to be transferred to a standstill or for a drive body to be brought to a standstill or for a drive body to be kept at a standstill, and for presetting an activation operating variable, and for changing the determined set operating variable into a relaxation operating variable by means of the activation operating variable, so that the relaxation operating variable is converted by an actuator into a relaxation driving force acting on the drive body for moving the drive body, wherein the activation operating variable is predefined so that the relaxation driving force at least temporarily exceeds the friction force acting on the drive body during the stationary control.

[0014] By adding the activation manipulated variable, which together with the set manipulated variable leads to the generation of a relaxation drive force which in turn exceeds the acting frictional force, it is ensured that after the drive body has come to rest or shortly before it reaches rest, at least a brief renewed or additional movement of the drive body occurs. In this way, in particular by relieving the stresses of the drive body, the undesirably stored potential energy can be reduced and the above-mentioned disadvantages associated with the undesirably stored potential energy, such as undesirable oscillations when the movement of the drive body is restarted, can be avoided. Exceeding means in a known manner that the value of the relaxation drive force, such as in particular an absolute value or another norm, at least temporarily exceeds the corresponding value of the frictional force acting on the drive body during rest control.

[0015] In an advantageous manner, the setting control variable is determined by the controller from the deviation between at least one movement parameter of the drive body and a stationary target variable predefined for the at least one movement parameter, so that the at least one movement parameter of the drive body is set to the predefined stationary target variable. According to an advantageous embodiment, a closed control circuit is used to set the at least one movement parameter. In this process, different methods known from control technology for adjusting / setting the at least one movement parameter can be used in an advantageous manner.

[0016] It should be noted that the use of closed regulating circuits is by no means mandatory for the implementation of the invention. In particular, it is also possible to dispense with the feedback of the measured motion variable and therefore just not use a closed regulating circuit ("feedback control", "closed-loop control"), but use controllers that are well known from regulation technology ("feedforward control" and "open-loop control"). Depending on the application, for example if appropriate measurement data for the motion variable to be set are not available, the use of a controller may be advantageous, and feedback-based regulation may be particularly preferred.

[0017] Another advantageous design of the present invention provides that the activation manipulated variable is determined and used to change the set manipulated variable only when the drive body has remained stationary for a preset minimum stationary duration, and / or the activation manipulated variable (in the form of a periodic signal with a preset activation amplitude and / or a preset activation frequency) is determined, wherein the activation manipulated variable preferably has a time average value corresponding to the value zero, and / or the activation manipulated variable is used to change the set manipulated variable only in a preset activation time period. The present invention can be precisely coordinated with a given application situation by appropriate changes / adjustments of these parameters, and can therefore be used particularly flexibly compared to the concepts of the prior art. The limitation of the activation manipulated variable to the activation time period in particular allows that the activation manipulated variable is not switched on for an unnecessarily long time, but only for the time required to reduce the potential energy. In this way, unnecessary control energy is not switched on, and first of all, energy is not wasted unnecessarily.

[0018] Likewise, within the scope of the present invention, the position of the drive body can be determined as a motion parameter of the drive body, and a target position for the determined position can be preset as a stationary target parameter, or of course the speed of the drive body can be determined as a motion parameter of the drive body, and a target speed for the disappearance of the determined speed can be preset as a stationary target parameter.

[0019] In the case where the position of the drive body is used as the motion variable of the drive body and the target position for the determined position is preset as the stationary target variable, in another advantageous embodiment of the present invention, it can be provided that the activation control variable is determined and used to change the setting control variable only when the value of the position deviation between the position of the drive body and the preset target position of the drive body at rest is greater than a preset deviation threshold value, wherein the sign of the activation control variable can be selected as a sign opposite to the sign of the position deviation or as a sign corresponding to the sign of the position deviation. Depending on the specific application, in this way, in addition to the above-mentioned potential energy reduction, a reduction of the control error still existing at rest can also be achieved many times, which can additionally allow an increase in the setting or control accuracy.

[0020] In other embodiments of the invention, it has generally proven to be advantageous to determine the position and speed of the drive body in a first coordinate direction as the motion variable, wherein the drive force generated by the actuator acts on the drive body in this first coordinate direction, and to determine a second position of the drive body in a second coordinate direction different from the first coordinate direction and a second speed of the drive body in the second coordinate direction as the further motion variable, and in this context to determine the activation actuation variable and use it to change the set actuation variable only if the value of a second position deviation between the determined second position and a second target position predefined for the second position is greater than a predefined second position threshold value. As will be explained in detail below, in particular, inclinations of the drive body can be reduced in this way, which inclinations are manifested in a plurality of spatial directions that differ from the spatial direction in which the set motion variable occurs and can also lead to the storage of potential energy.

[0021] In the case of drive systems that often occur in practice, an oscillating multi-body system with at least n resonance frequencies is formed in the drive system, which has a drive body on the one hand, but also includes n number of further mechanical bodies on the other hand, which are mechanically coupled to the drive body and on which corresponding friction and thus friction forces caused by the corresponding friction also act. In this case, it can be provided in a further particularly advantageous manner that an activation manipulated variable in the form of a periodic signal with a predetermined activation amplitude and / or a predetermined activation frequency is predefined, wherein the activation frequency is selected to be greater than the largest resonance frequency of the n resonance frequencies of the oscillating multi-body system, or is selected to be greater than or equal to the smallest resonance frequency of the n resonance frequencies of the oscillating multi-body system, or is selected to be equal to one of the n resonance frequencies of the oscillating multi-body system, wherein it can be provided in addition, if necessary, that the magnitude of the drive force resulting from the conversion of the relaxation manipulated variable by the actuator at least temporarily exceeds the sum of the friction forces acting on the drive body and the friction forces acting on the n number of further bodies (which arise from the respectively acting friction). These options are also a result of the flexibility currently provided. In certain cases it may be possible to avoid excitation at the resonance point as far as possible in order not to cause damage to the drive system, whereas in other cases excitation at the resonance point offers the possibility of producing a large effect with only a small excitation amplitude and thus achieving the goal of reducing potential energy or reducing mechanical stress as quickly as possible.

[0022] In addition, the aforementioned object is achieved by the drive system mentioned at the outset, the control unit of which is designed to determine a set operating variable (which alone leads to a driving force that cannot overcome the friction force) for a drive body to be transferred to a standstill or for a drive body introduced into a standstill or for a drive body held in a standstill, and to preset an activation operating variable, and to change the determined set operating variable into a relaxation operating variable by means of the activation operating variable, and the actuator of the drive system is further designed to convert the relaxation operating variable into a relaxation driving force acting on the drive body in order to move the stationary drive body, wherein the activation operating variable is preset so that the relaxation driving force at least temporarily overcomes the friction force acting on the drive body during the standstill adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is subsequently referred to Figures 1 to 7 Explained in detail, Figures 1 to 7 An exemplary, schematic and non-limiting advantageous design of the present invention is shown.

[0024] Figure 1 shows a regulation circuit of a multi-body system according to the prior art,

[0025] Figure 2shows a friction model known from the prior art,

[0026] Figure 3 shows a two-body system degenerating into a locked one-body system,

[0027] Figure 4 A control circuit with a control variable switching according to the invention is shown,

[0028] Figure 5a , 5b 5c shows a possible time curve of the activation of the control variable according to the invention,

[0029] Figure 6 shows a section of a long stator linear motor,

[0030] Figure 7 The application of the invention to solving the tilt of the shuttle of a linear motor is shown. DETAILED DESCRIPTION

[0031] Figure 1 A control circuit 1 for controlling a motion variable BG of a multi-body system MKS according to the prior art is shown. In the multi-body system MKS to be controlled, in the case shown, two bodies J are assumed. A , J K 、Drive body J A and drive body J A Mechanically coupled coupling body J K At this point it should be noted that by Figure 1 The multi-body system MKS regulated by the regulation circuit 1 shown can also have more than two bodies J A , J K , and can be provided, for example, as a three-body, four-body or five-body system, but can also have only one main body, in particular only one driving body J A In all these cases the problem of unintentional storage of potential energy can arise which is solved by the present invention.

[0032] Also note that Figure 1 The closed control circuit 1 shown is to be regarded as purely exemplary and serves in particular to illustrate the invention in a clear and practicable manner. The stationary control described below can also be realized without closed feedback. Therefore, the term "stationary control" includes both control in the classical sense with feedback and control without feedback within the scope of the present application. For the realization of the invention explained below, no restrictions arise from the use of control systems or from the use of classical control systems.

[0033] like Figure 1 The multibody system MKS shown can be a rotating or translating multibody system MKS, i.e., its main body JA , J K A multi-body system MKS that implements a translational motion, a rotational motion or a superposition of a translational and rotational motion. It is also possible that a body of the multi-body system MKS moves rotationally while another body moves translationally. Therefore, in the subsequent embodiments, general terms "body", "speed", "force", "axial force", etc. are used. However, similar terms "inertia", "rotational speed" or "angular velocity", "torque", "axial moment", etc. should also be included with respect to the rotating multi-body system MKS. As specific examples of multi-body systems MKS, there can be mentioned the drive shaft of a machine tool, a transmission train, a test bench with a load machine and a test object connected to the load machine via a mechanical shaft (for example an internal combustion engine to be tested), a pressure roller or other multi-body systems MKS.

[0034] exist Figure 1 In the case shown, the drive body J A and coupling body J K The mechanical coupling is carried out via a spring element c and a damping element d (corresponding to the stiffness usually indicated by "c" or the damping indicated by "d"). Here, the spring element c and the damping element d form an elastic mechanical axis. In a known manner, the drive body J A and coupling body J K The relative movement between them generates an axial force F transmitted through the spring element c and the damping element d. W , i.e. the axial force F transmitted through the mechanical axis formed by the spring element c and the damping element c W , the axial force affects the body J in a known manner A , J K movement.

[0035] For the following implementation scheme, it is assumed that the drive body J A and coupling body J K There is a non-negligible friction μ1, μ2 acting on it, which causes a non-negligible friction force F in a known manner. r1 、F r2 (Later with the help of Figure 2 The possible and sufficiently known friction mechanisms are discussed here). However, within the scope of the invention, this limitation is not an essential requirement, since only one drive body J A In particular, the drive system can also only be suitable for the application of the present invention (see Figure 6 and Figure 7 ), where there is no second coupling body J K , or coupling body J K It can be completely or almost frictionless. However, the relationships that are important for the invention are particularly clear and particularly easy to see with the friction-sensitive two-mass oscillator currently under consideration.

[0036] Friction may occur for different reasons, so the friction μ1, μ2 currently considered may be static friction or sliding friction or rolling friction or rolling friction or a combination of these frictions. K The friction μ2 on the drive body J may be greater than A The friction μ1 on appears significantly stronger. To illustrate the above friction, Figure 2 shows a friction model known from the prior art, in which the Coulomb friction μ C and viscous (velocity-dependent) friction μ v combination. Therefore, Figure 1 The frictions μ1 and μ2 shown can correspond to the Coulomb friction μ C , viscous (velocity-related) friction μ v Or a combination of these frictions.

[0037] The friction μ1 and μ2 are known in a known manner in the case of friction proportional to speed, for example, as a function of the product of friction and speed (μ·v), in the case of Coulomb friction μ C The friction force F acting on the main body is caused by the product of the friction and velocity signs (μ·sign(v)) in the case of static friction, the friction force compensating the driving force, etc. r1 、F r2 These relationships are sufficiently known to the person skilled in the art in the field of drive technology (see, for example, The mechatronics Handbook, RH Bishop, CRC Press, 2002) that the relevant details are not discussed in detail at this point.

[0038] About Driver J A and a coupling body J mechanically coupled to the driving body K , it is assumed in the present relationship that the driving force F which can be preset by the regulator R A Acts only on the drive body J A This is also not mandatory within the scope of the invention, so that the force that can be preset by the regulator R can also act on the coupling body J K However, the effect only on the drive body J A The driving force F A The limitation of J is helpful to explain the principle of the present invention, because only acting on the driving body J A The driving force F A In the coupling body J K The movement is only affected by the axial force F transmitted through the mechanical axis. W and acting on the coupling body J K The influence of friction μ2 on the

[0039] exist Figure 1In the coupling diagram shown, the drive body J can be obtained in particular. A Position x or driving body J A The velocity v or acceleration a or force etc. are used as the motion variable BG. In order to determine the position and / or velocity and / or acceleration and / or force, different possibilities are known in the prior art, which are sufficiently known to a person skilled in the art of drive technology, such as the use of encoders, such as rotary encoders or translational encoders. In the following embodiments, it is assumed, without limiting the generality, that the drive body J is determined and adjusted. A The position x is taken as the motion parameter BG.

[0040] Specifically, within the scope of the invention, the position x as the motion variable BG can be measured directly, for example by means of a position encoder, which directly generates a position measurement signal and therefore no longer requires further processing of the signal generated by the sensor in order to determine the speed measurement signal. However, the position x can also be determined from another measurement signal, for example by integrating the speed signal, or the position can be calculated from other signals, for example from a measured current or voltage or from a magnetic flux, etc., using observer techniques which are sufficiently known from control technology. How the drive body J is specifically determined is not a matter for the invention. A The processed motion parameter BG is unimportant.

[0041] exist Figure 1 In the case shown, the position x determined as the movement variable BG is supplied to the controller R. The controller R uses the movement variable BG and the target position x as input. soll Preset stationary target parameter B soll Find the value used to adjust the position x to the target position x soll The setting control parameter u s In this case, the target position x is usually determined in the controller R. soll and the position x, and from the determined deviation e, the control error e, the set control variable u is determined with the aid of a preset control rule s Such control rules can be various methods known from control technology, for example from the field of sliding mode control, backstepping control or model predictive control or flatness-based control. In practice, cascaded control circuits are often used in this context, in which the upper position controller predetermines the speed controller R of the lower level. v The target speed v soll As a manipulated variable, the lower speed regulator R v Then, by connecting the drive body J A The target speed can be adjusted by comparing the speed v of the target speed. Therefore, in this case, two or more movement parameters BG can also be used in the adjustment.

[0042] As we all know, in Figure 1 In the control circuit 1 shown, the set control variable u determined by the regulator R s No direct effect on the multibody system MKS, specifically no direct effect on the driving body J A Instead of setting the control parameter u s (Information signal) is also converted by actuator A into the corresponding power parameter F A , i.e., the actual (driving) force, the actual torque, the actual current, for example, the driving current i for forming the driving force A wait.

[0043] For practical implementation, the controller for adjusting the movement variable, in particular the controller R, can be implemented on suitable microprocessor-based hardware, preferably forming a control unit, such as a microcontroller, or in an integrated circuit (ASIC, FPGA). s (Information signal) converted into driving force F A The prior art also provides a plurality of possibilities for the actuator A that transmits (power signals), such as servomotors or general electric motors (asynchronous motors, synchronous motors, stepper motors), linear motors, hydraulic actuators, etc. As is common in multi-body systems MKS driven by servomotors, the main body of the multi-body system MKS can be, for example, a component of the servomotor, such as its rotor. Here, the above-mentioned microprocessor-based hardware for realizing the regulator, etc. can also be part of the servomotor and be connected to the above-mentioned sensor or encoder or rotary encoder cable. These relationships are sufficiently known to those skilled in the art in the field of regulation and / or drive technology, so that the relevant details will not be discussed in detail at this point.

[0044] In order to explain the problem solved by the present invention in detail, Figure 3 Firstly, it is shown Figure 1 The topological change of the multi-body system MKS shown is within the scope of the currently considered, exemplary position adjustment, especially in the body J A , J K During the operation of the multi-body system MKS, low or even vanishing velocities may occur for various reasons, for example, due to corresponding presettings by the operator or via a preset target value profile (target velocity = 0), or near the end of a positioning process, during which the drive body J A The position x is already at the target position x preset for position x soll Nearby, and the target position x soll is approached slowly, aiming to stay at the target position x sollPosition x and target position x soll Small deviations between the values, especially in combination with a speed that is also small in value, usually also result in a small set manipulated variable F required for the controller R. s , which results in a small driving force F A , which further leads to a small axial force F transmitted via the shaft W .

[0045] If the axial force F W The overcome friction μ2 now acts on the coupled body J of the multibody system MKS K What happens is that, despite the driving force F A different from zero and despite the axial force F W Different from zero, but the coupling body J K The vehicle is also braked, brought to a standstill and, if necessary, kept at a standstill. A And only the perception follows the driving force F less and less A The coupling body J K From the perspective of the regulator R, the coupling body J K Behaves as a body with very high or infinite inertia or with very high or infinite mass. In this case, the multibody system MKS can be represented in a first approximation as a locked single-body system, as Figure 3 shown.

[0046] If the coupling body J K Then it has been fixed, and the drive body J A Still moving, for example because the drive body has not yet reached the target position x set for it soll , then the driving body J A and coupling body J K Here, according to Hooke's law, when position x finally reaches the preset target position x soll When the potential energy E pot =c·(xx R ) 2 / 2 or potential energy E pot =c·(x soll -x R ) 2 / 2 is stored in the mechanical coupling. In addition to the stored potential energy E pot In addition, a shaft connection clamped in this way is also accompanied by a shaft restoring force F W =-c·(x soll -x R ), the axis restoring force must be compensated when stationary, because the drive body J to be positioned A Otherwise, it will move away from the target position x soll Resulting in a compensation force F for compensating the remaining restoring forceS =c·(x soll -x R )'s corresponding compensation setting manipulation parameters are contrary to the intention of the energy-saving system.

[0047] Permanent setting of control parameters F S =c·(x soll -x R ) may depend on static and dynamic factors as well as on the system state in previous time periods and is therefore usually difficult to model or estimate. In the case of exact modeling, the problem often arises in practice that such models are mathematically complex and therefore often cannot be used in real time. In addition to the potential energy E described at the beginning, which can be obtained from the above-mentioned pot Besides the problem of reducing the oscillations and vibrations caused by the above-mentioned restoring force, it is another reason to avoid unnecessary storage of potential energy in the drive body J. A The data are stored during the standstill period, i.e. during static regulation.

[0048] According to the invention, for this purpose a method for changing the controller manipulated variable u is provided. s The activation control parameter u akt , which is then aided by Figure 4 is explained in detail. Figure 1 For example, the embodiments of the multi-body system MKS or the regulator R or the control unit for implementing the regulator R are Figure 4 The coupling diagram shown is still valid. Figure 4 The coupling diagram shown also applies if, in addition to the position x, the velocity v or the acceleration a can also be detected as the movement variable BG to be controlled.

[0049] In order to achieve stress-free static adjustment, first Figure 4 The regulation circuit shown is set according to the drive body J A at least one motion parameter BG and a stationary target parameter B preset for at least one motion parameter BG soll The deviation e between them is used to obtain the set control parameter u s , where the desired setting control parameter u s Converted by actuator A to act on drive body J A The driving force F A , so as to set at least one motion parameter BG to a stationary target parameter B soll , so that the driving body J A is brought to rest and / or if the drive body J A If the system is already at rest, it remains at rest. During the rest control, a preferably constant, ie, time-invariant, target position is predefined as the rest target variable B. sollHowever, in the case of position control, the stationary target variable can have a value different from zero. In the case of speed control, the stationary target variable B is usually set soll , which corresponds to the vanishing target velocity, i.e., a target velocity with a value of zero.

[0050] Because the drive body J A is brought to a standstill and / or remains at a standstill, so that usually the result is that the controller R is controlled according to the preset standstill target variable B soll The set control parameter u is obtained s The driving force F A , the driving force no longer overcomes the driving body J A The friction force F r1 , i.e. the friction force generated by the friction μ1 in a known manner is no longer exceeded in terms of value. From this point on, within the scope of the present invention, the already mentioned activation control variable u is now presupposed. akt , and the desired setting control parameter u s By activating the manipulated variable u akt Change to the relaxation control parameter u ent Relaxation control parameter u ent It is then converted by actuator A to act on drive body J A The driving body J on which the stationary A Relaxation driving force F ent , where the activation control parameter u akt is preset so that the relaxation driving force F A During the stationary control, the current acting on the drive body J is at least temporarily exceeded. A The friction force F r .

[0051] Within the scope of the present invention, by activating the manipulated variable u akt "Change" sets the manipulated parameter u s This means that from setting the manipulation parameter u s and activation manipulation parameter u akt Generate new control parameters, especially relaxation control parameters u ent To this end, the manipulated variable u is activated akt Can be set with the control parameter u s Add, such as Figure 4 As shown, or activate the manipulated variable u akt Can be set with the control parameter u s Multiply, or activate the manipulation parameter u akt and set the control parameter u sThe two manipulated variables can be linked to each other via a predetermined mathematical relationship, for example, by the two manipulated variables serving as inputs of the dynamic multi-variable system and being mapped to a common output, which then corresponds to the relaxed manipulated variable u ent Given this relationship, it is possible for a correspondingly trained person skilled in the art to make a suitable choice to determine the relaxation control variable u ent Therefore, by activating the manipulated variable u akt Change the setting control parameter u s Of course, the following situations are also included, that is, setting the control parameter u s disappear, that is, assume the value to be zero, and relax the control parameter u ent Completely controlled by the activation parameter u akt Formation (relaxation control parameter u ent Usually corresponds to the activation of the manipulated variable u akt ). This scenario usually occurs when the activation control parameter u akt and set the control parameter u s The sum of the cases.

[0052] The last mentioned step according to the invention is Figure 4 In the embodiment shown, this occurs in the frame V representing the pilot control unit, wherein the activation of the manipulated variable u akt The determination of can also be carried out in the regulator R. Like the regulator R, block V can of course also be implemented on a suitable control unit. Figure 4 In the case shown, three signals are also provided to the frame V, namely the drive body J A The motion parameter BG is the driving body J A The motion parameter BG and the preset static control parameter B soll and the derivative BD of the motion variable BG determined by differentiation, which may correspond to the velocity, for example. Depending on the application, it may be advantageous to also form a further derivative of the motion variable BG, for example a second derivative, if, for example, acceleration is to be considered, or a third derivative, if, for example, jerk is to be considered.

[0053] It should be noted that it is by no means mandatory to feed all these variables to the frame V. It is important that the drive body J can be identified in the frame V. A Is it at rest, or at least close to reaching rest? This can be done, for example, by monitoring the speed v x Whether it corresponds to the value zero or is already very small within the preset duration, or whether the monitoring position corresponds to the target value x within the preset duration soll , which depends on which parameters are chosen as motion parameters.

[0054] By adding the activation manipulation parameter u aktIt is ensured that at least the main body J of the multi-body system appears A , J K The short re-movement of the activated manipulated variable and the set manipulated variable F s The interaction leads to the formation of a relaxation driving force F ent , which is a relaxation driving force that exceeds the sum of all the friction forces acting. A , J K Any existing stress in the mechanical coupling is relieved.

[0055] Preferably, it is ensured by appropriate technical precautions that the drive body J A The relaxation driving force F ent The induced movement results only in the regulated movement variable BG and the stationary target variable BG which is predefined for it. soll The new deviation e between the static control and the static target variable B is not exceeded during the static control. soll 10% of the value or the static target parameter B pre-set during static control soll 5% of the value or the static target parameter B pre-set during static control soll 1% of the value or the static target parameter B predefined during static control soll The preset maximum deviation of 0.5% of the value of ,max A person skilled in the art who has received general training in control technology knows which steps can be taken for this purpose, such as, for example, actuating variable limitation, which leads to a relaxation of the actuating variable F ent The friction force acting can only be slightly exceeded, for example, leading to a loosening of the control variable F ent Just 1% or 5% or 10% greater than the friction force acting.

[0056] In order to drive the body J A When stationary, the active manipulated variable u is further switched on without obligation akt , by activating the manipulation parameter u akt Change the setting control parameter u s Can be associated with other conditions. Specifically, within the scope of the present invention and of course in Figure 4 The coupling diagram shown can be set within the scope of only when the drive body J A At the preset minimum standstill duration t 0,min The activation control variable u is determined only when the interior remains stationary. akt And use it to change the adjustment setting control parameter u s Here, the minimum standstill duration t 0,minIt can be adapted to the particular given application and can be, for example, 0.01 seconds or 0.1 seconds or 1 second or 10 seconds, or also correspond to a larger or smaller time period.

[0057] Figure 5a-5c The activation control variable u according to the present invention is shown akt The common feature of the curves shown is that the activation control variable u akt Only during the preset activation time period t akt Different from zero. Activation time period t akt It can also be selected differently depending on the application so that no activation of the manipulated variable u akt The switching on is not necessarily too long, but not too short, in order to achieve the desired goal of reducing the potential energy. The time limits required for this are known to those skilled in the art, and these time limits vary according to the application.

[0058] exist Figure 5a In the curve shown, the activated control variable u akt With a preset activation amplitude A F and the preset activation frequency f F The form of the periodic signal is selected, wherein in particular, during the activation period t akt The time average value during corresponds to the value 0, which is usually very advantageous in practice, since these curves alone usually do not lead to a permanent deflection of the moving body. Figure 5b , activate the manipulated parameter u akt is implemented as a random signal and in Figure 5c is realized as having an increased amplitude A F The amplitude of the signal increases until the main body of the multi-body system MKS moves and the stored potential energy E pot Reduce.

[0059] In a particularly advantageous embodiment, the activation control variable u akt The activation amplitude A F and / or activation frequency f F and / or activation time period t add , and the activation manipulation parameter u akt Other characteristic parameters of , such as activation control variable u akt The slope of the ramp in the time curve can be adjusted by adaptive methods, in the drive body J A During the movement of , different algorithms from the field of adaptive systems can be used, such as the least squares method or the maximum likelihood method or other suitable algorithms. However, the activation control variable u aktThe curve used can also be fixed a priori, for example using basic knowledge about the friction forces μ occurring, etc., and the activation control variable u can always be used. akt It is also conceivable that during stationary control, the activation of the manipulated variable u akt A limited number of predefined time curves are selected, which can be based on randomness or can also be related to the actuator A and / or the drive body J. A Therefore, in order to predetermine or determine the activation control variable u akt , there are different possibilities and a person skilled in the art knows how to use them appropriately.

[0060] About activation frequency f F It should be noted that in this embodiment, the drive body J A and drive body J A Coupled coupling body J K An oscillating system is formed which in any case has at least one resonant frequency. In a particularly advantageous manner, it can be ensured that the resonant frequency of a given multi-body system MKS is not excited, which can be ensured, for example, by activating the frequency f F is selected to be greater, preferably significantly greater, ie, for example, two or five or ten times greater, than the resonance frequency of the oscillating multi-body system MKS. However, as mentioned above, it may also be meaningful and advantageous in some applications to make the activation frequency f F is precisely coordinated with the resonance frequency of the multi-body system MKS and thus activates the activation frequency at the resonance point, thereby activating the manipulated variable u akt The given activation amplitude A F The greatest possible effect is achieved. A deliberate selection between the resonance frequencies can also be advantageous, in particular in so-called rigid systems, whose resonance frequencies are far apart and where in this way a most uniform excitation of all bodies of the multi-body system MKS is possible.

[0061] Advantageously, the activation control variable u akt The activation frequency f F and activation amplitude A F , which makes the multi-body system MKS unable to completely follow the activation control parameter u akt By activating the manipulated parameter u akt The resulting movement serves only to compensate for the stresses in the drive train which are generated by the frictions μ1, μ2 described, for example, in particular static friction, usually at the end of the positioning process, when the operation is stopped. After a brief relaxation phase, the additionally switched activation control variable u akt Can be removed again in the stillness that occurs.

[0062] In a further advantageous aspect, as explained below, Figure 1 and Figure 4 Other parameters among the parameters shown can be combined to realize the present invention. Specifically, it can be arranged that only when the motion parameter BG and the stationary object parameter B soll The value of the deviation e between them should be higher than the preset deviation threshold e ,min The activation control parameter u is obtained only when akt And use it to change the setting control parameter u s , or you can set it to select the activation control parameter u akt The symbol is used as the same as the motion parameter BG and the stationary target parameter B soll The sign of the deviation e is opposite to that of the sign or the sign corresponds to the sign of the deviation e.

[0063] In a particularly advantageous manner, once the motion variable BG and the stationary object variable B soll The value of the deviation e between them is again less than the preset deviation threshold e min , then it can be terminated by activating the manipulation parameter u akt Set the control parameter u s Since any existing stresses are reduced by the invention and therefore unnecessary restoring forces have to be compensated more, energy can be saved in this way, firstly in applications with long rest phases.

[0064] Then with the help of Figure 6 and Figure 7 An important practical application of the invention is shown, which, however, is particularly useful for the invention with only a single drive body J A In the application, the drive body is not coupled to another body. Figure 6 A transport device 1 in the form of a long stator linear motor (LLM) 10 is shown by way of example for transporting the transport units T1, . . . , T k The long stator linear motor 10 is composed of a plurality of separate stator segments S1, ..., S p constitute, Figure 6 Only the stator segment S1 with the transport unit T1 is shown. In conjunction with the above-described embodiments, the mechanical body of the transport unit T1 corresponds to the drive body J according to the invention. A In the long stator linear motor 10, a plurality of stator segments S1, ..., S p Usually assembled to form a long stator 2 that is fixed in position. Stator segments S1, ..., S p For this purpose, they can be arranged on a stationary support structure SK. pIt can be implemented in different geometries, for example as a straight section or a curved section, in order to realize different transport paths.

[0065] Electrical drive coil L m1 , ..., L mn In a known manner, the stator segments Sm are arranged in the longitudinal direction along the long stator 2 (in each stator segment Sm). Figure 6 Only the stator segment S1 is shown in FIG. 1 , where n is an integer greater than one), the drive coil is connected to the transport unit T1, ..., T k The driving magnets Y1, ..., Y L In a similarly known manner, the coil adjustment units 101, 102 are used to adjust / set the drive coil L m1 , ..., L mn The coil voltage U L1 , ..., U Ln For each transport unit T1, ..., T k Generate driving force F A , so that transport units T1, ..., T k and the drive body J connected thereto A1 , ..., J Ak Move along the long stator 2. Usually, the driving force F is generated together A Multiple drive coils L m1 , ..., L mn Acts simultaneously on transport units T1, ..., T k For the sake of clarity, Figure 1 Only two coil adjustment units 101, 102 are shown. Of course, each drive coil L in each stator segment Sm m1 , ..., L mn Each coil voltage U L1 , ..., U Ln The coil adjustment units 101, 102 are used for adjustment, wherein a plurality of coil adjustment units 101, 102 can also be summarized as an adjustment unit. A possible implementation of the coil adjustment units 101, 102 is also provided by microprocessor-based hardware, such as a microcontroller and an integrated circuit (ASIC, FPGA). In combination with the above-mentioned embodiments, the drive magnets Y1, ..., Y L and the drive coil L arranged at the long stator 2 m1 , ..., L mn The system formed forms an actuator A which converts the manipulated variable F required by a controller R, preferably a position controller R, for the regulated movement of the transport unit T1 s Converted into driving force F to move transport unit T1 A .

[0066] In the long stator linear motor 1 Figure 6 In the embodiment shown, each transport unit T1, ..., T k The transport controller 100 upstream of the coil control units 101 , 102 can be used to control the speed, acceleration, trajectory, direction individually and in combination with the other transport units T1 , . . . , T k To this end, for each transport unit T1, ..., T k The transport controller 100 can continuously preset position specifications (also equivalent to speed specifications), which are converted by the coil adjustment units 101, 102 into transport units T1, ..., T k The coil voltage U required for the movement L11 , ..., U Lpn In this case, the coil control units 101, 102 receive target variables SG1, . . . , SG n , wherein the target variable may in particular be the corresponding target position x soll or the corresponding target speed v soll Since this basic principle of a long stator linear motor is well known, it will not be discussed in detail at this point. In the transport controller 100, in particular, it is possible to realize Figure 1 and Figure 4 The frame in question, i.e. the position regulator R x and pre-control unit V.

[0067] Then with the help of Figure 7 Describe how to Figure 6 The present invention is advantageously used in the long stator linear motor 10 shown. Specifically, Figure 7 Four temporally consecutive scenarios a), b), c) and d) are shown. In scenario a), the transport unit T1 and thus the drive unit J A Move in the coordinate direction xR at a reduced speed v (to the left) to the preset target position x soll As can be seen from the scenarios a) and b), the upper side OS of the long stator 2 has a large friction μ1, which hinders the drive body J A In the case of long-stator linear motors 10, so-called V-rollers or V-groove guide rollers are usually arranged on the upper side, which usually lead to an increase in friction. Usually, in the transport unit T1 of the long-stator linear motor, a position sensor, for example a magnetoresistive AMR sensor which is sufficiently known from the prior art, is arranged at a selected and arbitrary point, for example at the geometric center of the transport unit T1. If now a given position x in the middle of the transport unit T1 is detected as a movement variable BG and converted into a preset target position x sollStationary target parameter B soll , but the part of the transport unit T1 facing the upper side OS is blocked due to friction, then the tilt of the transport unit T1 occurs, as shown in scenario b). Although the position x in the coordinate direction xR corresponds to the desired target position x soll However, due to the above-mentioned inclination, the transport unit T1 or the mechanical part of the transport unit T1, that is, the driving body J A itself is distorted, which leads to undesired storage of potential energy and associated disadvantages.

[0068] However, according to the invention, in scenario c), after the transport unit T1 has come to a standstill, the manipulated variable u akt is now switched on, so that the transport unit T1 is in vibration, the potential energy is removed from the system by the averaging effect, and the current tilt is resolved. The result of this process is scenario d), in which the transport unit T1 is in the predefined target position x in the x direction xR. soll , but the described tilt is eliminated.

[0069] Because as in Figure 7 The tilt described in the scenarios a), b), c) and d) is not shown in the movement direction xR, but in the movement direction yR which is different from the movement direction xR, for example, in that a point on the transport unit T1 located on the upper side OS is located at a target value y preset for the point in the coordinate direction yR. soll above or below, so within the scope of the present invention, the following process can be used to handle these situations.

[0070] Specifically, the first thing that can be set is to obtain the driving body J A The second position y and the driving body J in the second coordinate direction yR different from the first coordinate direction A The second velocity v along the second coordinate direction yR y Based on this, it can be set that only when the second position y obtained is consistent with the second target position y preset for the second position y soll The second position deviation e y The value is greater than the preset second position threshold y min When the activation control parameter u is obtained akt And use it to change the setting control parameter u s , so that Figure 6 and Figure 7 In the particular case of the long stator linear motor 10 shown, intervention is only performed when the tilt discussed above is present.

Claims

1. A driving body (J A ) static adjustment method, friction force (F r ) acts on the driving body, wherein, Obtain the setting control parameter (u s ), and converts the set manipulated variable into a variable acting on the drive body (J) by means of an actuator (A) A ) on the driving force (F A ) so that the driving body (J A ) is introduced into a stationary state and / or is kept in a stationary state, characterized in that a drive body (J) is to be transferred into a stationary state or introduced into a stationary state or is to be kept in a stationary state A ) to obtain the setting control parameter (u s ), the set control variable alone does not lead to overcoming the friction force (F r ) driving force (F A ), preset activation control parameter (u akt ), and the obtained setting control parameter (u s ) through the activation control variable (u akt ) is changed to the relaxation control parameter (u ent ), and the relaxation control parameter (u ent ) is converted by the actuator (A) to act on the driving body (J A ) on the relaxation driving force (F ent ) for making the driving body (J A ) movement, wherein the activation control variable (u add ) is preset so that the relaxation driving force (F ent ) during the stationary setting at least temporarily exceeds the force acting on the drive body (J A ) on the friction force (F r ).

2. The method according to claim 1, characterized in that The drive body (J) is connected to the drive body (J) by the regulator (R). A ) and a stationary target parameter (BG) preset for the at least one motion parameter (BG) soll ) to obtain the set control parameter (u s ) so that the driving body (J A ) is set as the preset stationary target parameter (B soll ), or by means of a controller from a stationary target parameter (BG) preset for the at least one motion parameter (BG) soll ) to obtain the set control parameter (u s ), without obtaining the setting control parameter (u s ) taking into account the at least one motion parameter (BG).

3. The method according to claim 2, characterized in that The driving body (J A ) is determined by the relaxation driving force (F ent ) causes the at least one motion parameter (BG) to be different from the static parameter (BG) preset therefor soll ), wherein the deviation does not exceed the preset stationary target variable (B soll ) or the preset static target parameter (B soll ) or the preset static target parameter (B soll ) or the preset static target parameter (B soll ) with a preset maximum deviation of 0.5% of the value.

4. The method according to any one of the preceding claims, characterized in that Acting on the driving body (J A ) on the friction force (F r ) is caused by static friction or sliding friction or rolling friction or rolling friction or a combination of these frictions.

5. The method according to any one of the preceding claims, characterized in that Only when the driving body (J A ) within the preset minimum standstill duration (t 0,min ) is stationary, the activation control variable (U akt ) and uses the activation manipulated variable to change the set manipulated variable (u s ).

6. The method according to any one of the preceding claims, characterized in that The form of the calculation is a preset activation amplitude (A F ) and / or a preset activation frequency (f F ) is the activation control parameter (u akt ).

7. The method according to any one of the preceding claims, characterized in that The activation control parameter (u akt ) in the preset activation time period (t add ) is used to change the set control parameter (u s ).

8. The method according to any one of the preceding claims, characterized in that The activation control parameter (u akt ) corresponds to the value zero.

9. The method according to any one of claims 2 to 8, characterized in that The driving body (J A ) is obtained as the position (x) of the driving body (J A ) and the target position (x) for the position (x) being determined. soll ) is preset as the stationary target parameter (B soll ), or the driving body (J A ) speed (v x ) is obtained as the driving body (J A ) and for the velocity to be determined (v x )'s disappearing target speed (v soll ) is preset as the stationary target parameter (B soll ).

10. The method according to any one of claims 2 to 9, characterized in that The driving body (J A ) is obtained as the position (x) of the driving body (J A ) and the target position (x) for the position (x) being determined. soll ) is preset as the stationary target parameter (B soll ), wherein only when the driving body (J A ) and the position (x) of the driving body (J A ) in the stationary preset target position (x soll ) between the position deviation (e x ) is greater than the preset deviation threshold (e x,min ), the activation control parameter (u akt ) and uses the activation manipulated variable to change the set manipulated variable (u s ).

11. The method according to claim 9, characterized in that The activation control parameter (u akt ) is chosen to be consistent with the position deviation (e x ) or is selected to have a sign opposite to the sign of the position deviation (e x )'s symbol.

12. The method according to claim 9, 10 or 11, characterized in that Once the position deviation (e x ) is lower than the preset deviation threshold (e x,min ), then terminate the setting of the control parameter (u s ) through the activation control variable (u akt ) changes.

13. The method according to any one of the preceding claims, characterized in that The driving body (J A ) and friction act on n number of other bodies, especially friction (μ R ) acts on the coupling body (J K ) are mechanically coupled and utilize n number of other bodies to form a multi-body system capable of oscillation with at least n resonant frequencies.

14. The method according to claim 13, characterized in that The preset form is a preset activation amplitude (A F ) and / or a preset activation frequency (f F ) is the activation control parameter (u akt ), wherein the activation frequency (f F ) is selected to be greater than the maximum resonance frequency of the n resonance frequencies of the oscillatory multi-body system (MKS), or is selected to be greater than or equal to the minimum resonance frequency of the n resonance frequencies of the oscillatory multi-body system (MKS), or is selected to be equal to one of the n resonance frequencies of the oscillatory multi-body system (MKS), and / or from the relaxation manipulation variable (u) controlled by the actuator (A) ent ) is converted into a driving force (F A ) at least temporarily exceeds the value acting on the drive body (J A ) and the sum of the friction forces (μ) acting on n number of other bodies resulting from the separately acting friction (μ).

15. The method according to any one of the preceding claims, characterized in that Determine the driving body (J A ) in the first coordinate direction (xR) and the velocity (v x ) as the motion parameter (BG), and the driving force (F A ) acts on the driving body (J along the first coordinate direction (xR) A ) on the driving body (J A ) in a second coordinate direction (yR) different from the first coordinate direction and the driving body (J A ) along the second coordinate direction (yR) of the second velocity (v v ) as a further movement variable (BG), and only when the determined second position (y) is in agreement with a second target position (y) predefined for the second position (y) soll ) between the second position deviation (e y ) is greater than the preset second position threshold (y min ), the activation control parameter (u akt ) and uses the activation manipulated variable to change the set manipulated variable (u s ).

16. A drive system comprising a movable drive body (J A ), friction (F r ) acts on the driving body, wherein, A control unit and an actuator (A) are provided, wherein the control unit is designed for the drive body (J A ) to obtain the set control parameter (u s ), wherein the actuator (A) is designed to set the desired control variable (u s ) is converted to act on the driving body (J A ) on the driving force (F A ) so that the driving body (J A ) is introduced into a stationary state and / or is kept in a stationary state, characterized in that the control unit is further designed to provide a drive body (J) to be transferred into a stationary state or introduced into a stationary state or kept in a stationary state A ) to obtain the setting control parameter (u s ), the set control parameter alone cannot overcome the friction force (F r ) driving force (F A ), and the control unit is further designed to preset the activation control variable (u akt ), and through the activation control parameter (u akt ) The obtained setting control parameter (u s ) is changed to the relaxation control parameter (u ent ), and the actuator (A) is further designed to adjust the relaxation control variable (u ent ) is converted to act on the driving body (J A ) on the relaxation driving force (F ent ) so that the driving body (J A ) movement, wherein the activation control variable (u akt ) is preset so that the relaxation driving force (F ent ) during the stationary setting at least temporarily overcomes the effect on the drive body (J A ) on the friction force (F r ).

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