Safety function

Abstract

To ensure particularly good protection of individuals in the electromagnetic transmission system (2), a safety area (S) is provided in the transmission area (20). In addition, a safety function is provided which ensures that the transmission unit (1) reaches the safety area (S) at a speed (v) less than or equal to the safety speed (v_S) and / or with a transmission unit force (F1) less than or equal to the safety force (F_S) and / or with a transmission unit energy (E1) less than or equal to the safety energy (F_S), or prevents the transmission unit (1) from reaching the safety area (S), in accordance with a predetermined safety requirement level.

Description

Field of the Invention

[0001] The present invention relates to a method for controlling a transmission unit of an electromagnetic transmission system, preferably a long-stator linear motor or a planar motor, wherein the electromagnetic transmission system includes a control unit and drive coils arranged in a transmission area, and wherein the control unit supplies power to the drive coils during normal operation such that a magnetic field coupled to the transmission unit moves in the moving direction in the transmission area to move the transmission unit in the moving direction. Furthermore, the present invention also relates to an electromagnetic transmission system including a control unit, a plurality of drive coils arranged in a transmission area, and at least one transmission unit, wherein the control unit is designed to supply power to the drive coils such that a magnetic field coupled to the transmission unit moves in the moving direction in the transmission area to move the transmission unit in the moving direction. Background Art

[0002] An electromagnetic transmission system includes a transmission area and one or more transmission units, wherein drive coils are provided in the transmission area. Similarly, magnets (usually permanent magnets) are provided on the transmission units. By supplying power to the drive coils by means of a control unit, a moving magnetic field is generated in the transmission area, and the moving magnetic field interacts with the magnets on the transmission units. Thereby, a propulsive force is generated on the transmission units, and thus the transmission units move in the moving direction in the transmission area.

[0003] In order to meet the requirements of modern flexible logistics units, long-stator linear motors (LLMs) are increasingly used as an alternative to conventional continuous conveyors (e.g., rotary-to-linear conversion units such as rotary motors on conveyor belts) as electromagnetic transmission systems. The long-stator linear motor is characterized by better and more flexible utilization over the entire working area. Therefore, a range of speeds and accelerations from zero to the maximum value can be utilized. In addition, advantages include individual adjustment or control of the movable transmission units (back and forth), better energy utilization, reduced maintenance costs due to a reduced number of wearing parts, simple replacement of the transmission units, efficient monitoring, simple error detection, and optimization of the received current by eliminating current gaps.

[0004] The stator of a long-stator linear motor forms a transmission path and consists of a large number of drive coils arranged adjacent to each other in the moving direction. These drive coils are controlled individually or in groups, and usually, multiple drive coils are each grouped in a transmission section. Therefore, the transmission path of the long-stator linear motor represents the transmission area and is in principle implemented in one dimension. This means that the movement of the transmission unit is in principle one-dimensional along a predetermined transmission path. However, the transmission path can be arbitrarily guided in space and also has branches and / or switches.

[0005] Likewise, a planar motor can be provided as the electromagnetic transmission device, for example. The planar motor can be used, for example, in the production process, where a very flexible transmission process with complex movement curves can be achieved. Different from the long-stator linear motor, the planar motor has a transmission plane as the transmission area. The transmission plane is implemented two-dimensionally in principle (for example, in the xy plane). The drive coils are arranged distributively in the transmission plane to generate a magnetic field that can move two-dimensionally in the transmission plane. Advantageously, the magnets are also arranged distributively two-dimensionally on the transmission unit to interact with the magnetic field and move the transmission unit in the transmission plane. The drive coils and the magnets are advantageously arranged such that, in addition to the one-dimensional movement along the axes spanned by the transmission plane (the x-axis and the y-axis in the xy plane), a more complex two-dimensional movement of the transmission unit in the transmission plane is also possible. In principle, only one-dimensional movement can also be specified in the transmission plane. In this case, the magnets and the drive coils can only be arranged one-dimensionally. The functionality and construction of the planar motor are known in principle and, for example, US 9,202,719 B2 can be cited.

[0006] If a user or an unauthorized person enters the safety area of the electromagnetic transmission system, it is necessary to protect this person from injury to ensure that, in particular, no harm is caused to individuals by the moving transmission unit.

[0007] Therefore, the electromagnetic transmission system is usually enclosed to prevent individuals from entering. However, even in the case of an enclosed electromagnetic transmission system, it is necessary for the user to enter the electromagnetic transmission system, especially when setting up work and / or maintenance work is being carried out. For this reason, a protective door is usually provided in the enclosure. However, entering the electromagnetic transmission system through the protective door is very time-consuming and increases the setup time or maintenance duration.

[0008] However, what is regarded as a particularly major disadvantage is that these protective doors invalidate the actual protection through the enclosure, whereby a relatively high risk of personal injury is again created by opening the corresponding protective door. In addition, the enclosure increases the construction cost of the electromagnetic transmission system.

[0009] As a supplement or replacement to the enclosure, when a user or an unauthorized person enters the safety area of the electromagnetic transmission system, the energy supply of the transmission unit can also be shut off by the electromagnetic transmission system. However, since the transmission unit has a very high torque with very little friction, the braking performance inside the system is very low in the case of releasing energy (for example, the safe torque off function (STO function)), which results in a relatively large braking distance. Here, an active braking concept for achieving a more rapid braking of the transmission unit can help. For example, US 2012 / 193172 A1 discloses a braking winding for generating a braking effect that is specifically installed on a linear motor. Summary of the Invention

[0010] The object of the present invention is to describe a safety function for an electromagnetic transmission system, which enables particularly good protection of individuals.

[0011] According to the present invention, this object is solved by a method, in which a safety area is provided in the transmission area, and a safety function is provided, which ensures that the transmission unit reaches the safety area at a speed less than or equal to the safety speed and / or with a transmission unit force less than or equal to the safety force and / or with a transmission unit energy less than or equal to the safety energy according to a predetermined safety requirement level, or prevents the transmission unit from reaching the safety area.

[0012] Furthermore, this object is solved by an electromagnetic transmission unit, in which a safety area is provided in the transmission area, and a safety module is provided, which is designed to ensure that the transmission unit reaches the safety area at a speed less than or equal to the safety speed and / or with a transmission unit force less than or equal to the safety force and / or with a transmission unit energy less than or equal to the safety energy according to a predetermined safety requirement level, or prevents the transmission unit from reaching the safety area. The safety module is used to implement the safety function.

[0013] The safety function can be permanently activated, but can also be activated by triggering a safety state.

[0014] For example, when an individual is in the dangerous area of the electromagnetic transmission system, especially in the safety area itself, the safety state can be triggered. There can be provided, for example, a grating, a laser scanner, a camera system, safety contacts on a protective door, etc. to identify the individual. However, the safety state can also be triggered in case of system overload, too high voltage or loss of position or speed information, for example. The safety state can be triggered again, for example, by triggering an emergency signal.

[0015] By providing the safety function according to the present invention according to a predetermined safety requirement level, complex enclosures of the electromagnetic transmission system can be dispensed with, thereby eliminating the risk of entry through a protective door. This simplifies the cooperation between the user and the electromagnetic transmission system, thereby increasing the effectiveness and flexibility of the operation of the electromagnetic transmission system.

[0016] The safety requirements can be implemented according to international standard series and / or international standards (e.g., the standard series IEC 61508), where IEC 61508 as a standard series has no release date but versions. The safety requirements of IEC 61508 Ed 1 or Ed 2 can be optionally used. The standard series IEC 61508 differentiates between different safety requirement levels (SIL - Safety Integrity Level) depending on the risk of the hazard. Here, SIL 0 describes a very low risk, while SIL 4 describes a very high risk, and the remaining risk left depends on the selected safety requirement level. Depending on the selected safety requirement level, construction and quality assurance measures can be defined to ensure the functionality of the safety function. In particular, it is ensured that in the case of the failure of safety - related components of the electromagnetic transmission system, the system does not terminate in an undefined and thus potentially dangerous state.

[0017] Preferably, the safety function is implemented at least partially, preferably fully redundantly. Thus, the failure of components of the safety function can be prevented. Since an electromagnetic transmission system (e.g., a long - stator linear motor or a planar motor) usually includes multiple transmission segments, redundancy can be achieved by combining relative or successive transmission segments. For this purpose, the safety function can be implemented separately and redundantly on each of the participating transmission segments, which is particularly advantageous when each of the individual transmission segments is a closed drive element. In this case, the mutual dependencies of the redundant implementation can be reduced or completely avoided.

[0018] The safety function preferably includes a diagnostic function that checks the functional operation of the safety function.

[0019] Thereby, the functionality of the safety function can be preferably checked and ensured in all operating states.

[0020] Preferably, the safety function at least meets the safety requirement level 1 (SIL 1) according to the standard series IEC 61508.

[0021] Thereby, single - fault safety can be ensured, which means that after a failure of the safety function, the functionality of the safety function itself will continue to be guaranteed.

[0022] Preferably, the safety function meets further safety requirements according to at least one of the standard series IEC 61508 and / or the standard ISO 13849 - 1:2015 - 12, IEC 62061:2005.

[0023] Accordingly, the safety module can at least meet the safety requirement level (SIL) 1 according to the standard series IEC 61508, and particularly preferably meet further safety requirements of at least one of the standard series IEC 61508 and / or the standard ISO 138491:2015-12, IEC 62061:2005.

[0024] Of course, in the safety function scope of the transmission area, multiple safety areas meeting the same or different safety requirement levels can be provided. Similarly, the same or different safety areas and / or safety requirement levels can be applied to different transmission units.

[0025] Preferably, a safety area is fixedly provided in the transmission area, and particularly preferably, the safety area includes at least a part of the transmission section arranged in front of the transmission unit in the moving direction of the transmission area.

[0026] Thereby, a fixedly arranged safety area can be realized in the transmission area, and this safety area describes, for example, particularly safety-related sections (for example, critical transmission sections).

[0027] The position of the safety area in the transmission area can also be dynamically determined. The safety area can start or end at the beginning or end of the transmission section, or at a fixed pre-given or flexibly determined distance before or after the transmission section and / or the transmission unit, or start and / or end at a fixed pre-given position on the transmission area. The flexible position of the safety area and / or the flexible distance of the safety area before or after the transmission section and / or the transmission unit can be determined, for example, due to the main parameters of the transmission unit (speed, load, moving direction, characteristics of the goods being transported (for example, temperature),...), the position of an individual, etc.

[0028] A safety deceleration area can be provided in front of the transmission unit in the moving direction, and the safety area starts after this safety deceleration area. In the case of a planar motor as an electromagnetic transmission system, for example, a deceleration area can be arranged around the safety area.

[0029] A safety deceleration area can be fixedly pre-given or flexibly determined (e.g., due to main parameters). The ensured braking distance of the transmission unit can be used, for example, as the safety deceleration range. The safety area can (via the deceleration area) depend only on the position of the transmission unit (and possibly main parameters). However, a hybrid form is also conceived, in which the safety area depends in principle on the position of the transmission unit, but is also determined with respect to the (structural) characteristics of the transmission area. Thus, for example, a transmission section located in front of the transmission unit in the moving direction (e.g., the next transmission section located in front of the transmission unit in the moving direction) can be defined as the safety area. Thereby, the safety area depends on the position of the transmission unit and the arrangement of the transmission section in the transmission area. Here, the safety area can also include a fixedly pre-given or flexibly determined part of the transmission area before or after a transmission section, which is located in front of the transmission unit in the moving direction. Similarly, the safety area can only start after a fixedly pre-given or flexibly determined distance before or after a transmission section, which is located in front of the transmission unit in the moving direction.

[0030] The safety module preferably includes a braking element arranged on the transmission unit and / or in the transmission area, which is designed to ensure that the movement of the transmission unit is braked within the scope of the safety function according to a predetermined safety requirement level, such that the transmission unit reaches the safety area at a speed less than or equal to the safety speed and / or with a transmission unit force less than or equal to the safety force and / or with a transmission unit energy less than or equal to the safety energy, or to prevent the transmission unit from reaching the safety area.

[0031] The task of the braking element is, within the scope of the safety function, to reduce the speed of the transmission unit such that the speed of the transmission unit when reaching the safety area is less than or equal to the safety speed, and / or to reduce the transmission unit force of the transmission unit such that the transmission unit force is less than or equal to the safety force, and / or to reduce the safety energy such that the safety energy is less than or equal to the transmission unit energy or does not reach the safety area at all.

[0032] The safety speed and / or the safety force and / or the safety energy can be fixedly pre-given or flexibly determined, for example, according to main parameters. The braking element can include an electrical, electromechanical, pneumatic or hydraulic braking system and must in principle meet a predetermined safety requirement level. Depending on the selected safety requirement level, it may also be necessary to ensure that the corresponding safety requirement level is met when determining the dimensions of the electrical and / or electromechanical and / or pneumatic and / or hydraulic components.

[0033] For example, a transmission section with particularly large forces can be set as the braking element, which can decelerate or stop the transmission unit accordingly before the safety area through the action of these forces.

[0034] In addition, a magnetic and / or magnetizable braking object can be provided as a braking element, which can be arranged on the transmission unit and / or in the transmission area. In the scope of the safety function, the braking object can be magnetically coupled to a counter-braking object, thereby reducing the speed of the transmission unit. This deceleration can be carried out by means of a magnetic resistance opposing the movement of the transmission unit. In the case of a transmission unit mechanically guided in the direction of movement, the braking effect can also be increased by those parts of the magnetic resistance perpendicular to the mechanical guidance system, since the frictional force is generally a function of the normal force. In addition, the deceleration can be carried out by eddy currents induced by the change of the magnetic field over time, opposing the magnetic field and thus the movement of the transmission unit. Of course, the mentioned magnetic acting mechanisms for deceleration can also be combined.

[0035] Since the mentioned magnetic acting mechanisms decrease exponentially with distance, an increased braking effect can be achieved when the transmission unit approaches the magnetic and / or magnetizable braking object. In addition, the mentioned magnetic acting mechanisms increase linearly with the effective area. An increased braking effect can be achieved by increasing the effective area (e.g., by laterally sliding the braking object between the transmission unit and the transmission section).

[0036] Therefore, in the scope of the safety function, the distance between the braking object and the counter-braking object can be reduced, and / or the effective area of the braking object and / or the counter-braking object can be increased, and thus the transmission unit can be decelerated.

[0037] If the distance between the braking object and the counter-braking object is greater than zero, the deceleration is carried out contactlessly.

[0038] In addition, a nozzle for jetting a gas or a liquid jet (e.g., an air or water jet) can be provided as a braking element, wherein the gas or liquid jet brakes the transmission unit.

[0039] Likewise, a preferably mechanically elastic braking object can be provided as a braking element, which can be arranged on the transmission unit and / or in the transmission area. In the scope of the safety function, the braking object can come into contact with a counter-pressure object, thereby decelerating the transmission unit. Thus, the braking object and the counter-pressure object can act as a block brake.

[0040] The magnetic and / or magnetizable braking object can also be combined with a mechanical and / or elastic braking object. Such a combined braking element brakes contactlessly up to a distance greater than zero between the braking object and the counter-braking object, and brakes with an increased force when the braking object comes into contact with the counter-pressure object.

[0041] The safety module preferably includes a blocking element arranged on the transmission unit and / or in the transmission area, which is designed to ensure that the movement of the transmission unit is blocked with a predetermined safety requirement level, so as to avoid reaching the safety area.

[0042] In principle, the transmission unit is prevented from reaching and entering the safety area by means of a blocking element. The blocking element may include electrical and / or electromechanical and / or hydraulic and / or pneumatic components, where the required safety functions are taken into account when sizing the respective components.

[0043] Preferably, a mechanically elastic blocking object (such as a screw) can be provided as the blocking element. Within the scope of the safety function, the blocking object can engage with a counter-blocking object, thereby blocking the movement of the transmission unit before it reaches the safety area.

[0044] The blocking element can also be combined with a braking element (for example, by also using the braking object as the blocking object). Thus, the combined braking object and blocking object brake when contacting a counter-pressure object and block when engaging with a counter-blocking element. Such a combined element can optionally be used as a blocking element or a braking element depending on the safety requirement level, the speed of the transmission unit or other predefined parameters, where the counter-pressure object and the counter-blocking object can also be the same.

[0045] The safety module preferably includes a deflection element arranged on the transmission unit and / or in the transmission area, which is designed to ensure that the movement of the transmission unit is deflected from the safety area before reaching the safety area with a predefined safety requirement level.

[0046] Thereby, it can be ensured that the transmission unit does not reach the safety area, because the transmission unit is deflected to avoid entering the safety area.

[0047] The deflection can be carried out by a mechanical deflection element (such as a mechanical switch). The deflection element may include electrical and / or electromechanical and / or hydraulic and / or pneumatic components, where the required safety functions are taken into account when sizing the respective components.

[0048] In addition, the deflection can be carried out without contact. A nozzle for jetting a gas or liquid jet (such as an air or water jet) can be provided as the deflection element, where the gas or liquid jet deflects the transmission unit so that the transmission unit does not reach the safety area. Magnetic and / or electromagnetic deflection elements can be provided, where the deflection element deflects the transmission unit by means of magnetic and / or electromagnetic forces so that the transmission unit does not reach the safety area.

[0049] Of course, a safety module including a combination of a braking element and / or a blocking element and / or a deflection element can also be conceived. In principle, the safety module or the safety function must meet a predefined safety requirement level. Therefore, according to the design, the included braking element and / or blocking element and / or deflection element must also meet the predefined safety requirement level.

[0050] Within the scope of the safety function, at least a part of the drive coil operates in an idling state for at least a period of time.

[0051] Thereby, the associated drive coil has been de-energized so that the transmission unit no longer moves actively further. Idling can be advantageous especially in combination with a braking element and / or a blocking element and / or a deflecting element.

[0052] Preferably, within the scope of the safety function, at least a part of the drive coil operates in a short-circuit state for at least a period of time.

[0053] Thereby, the transmission unit is braked and, similar to using a braking element, ensures that the transmission unit reaches a safe area at a speed less than or equal to the safe speed and / or with a transmission unit force less than the safe force and / or with a transmission unit energy less than the safe energy according to a predetermined safety requirement level, or prevents the transmission unit from reaching the safe area.

[0054] The transmission unit moves in the transmission area of the electromagnetic transmission system without appropriate action until it stops with a further slight deceleration (due to the desired frictionless or low-friction support or guidance of the transmission unit in the transmission area), where the transmission unit itself generates a moving magnetic field through the excitation magnet. This magnetic field moves with the transmission unit in the transmission area and thus also has the speed of the transmission unit. Here, this magnetic field also interacts with the drive coil, which has no effect on the disconnected terminals of the drive coil. However, the drive coils magnetically coupled to the transmission unit each induce a coil short-circuit current via an electromagnetic force (EMF) when the terminals are short-circuited. This coil short-circuit current cancels the magnetic field caused by the transmission unit according to Lenz's law, thereby braking the transmission unit relatively quickly. Therefore, preferably, the short circuit of at least a part of the drive coil is maintained permanently.

[0055] Particularly preferably, within the scope of the safety function, at least a part of the drive coil operates in a short-circuit state for at least a first period of time, while at least a part of the drive coil operates in an idling state for at least a second period of time.

[0056] Thereby, the transmission unit is braked particularly effectively and, similar to using a braking element, ensures that the transmission unit reaches a safe area at a speed less than or equal to the safe speed and / or with a transmission unit force less than the safe force and / or with a transmission unit energy less than the safe energy according to a predetermined safety requirement level, or prevents the transmission unit from reaching the safe area.

[0057] In the case of a short circuit, the coil terminals involved are closed, and in the case of idling, the coil terminals involved are open. By appropriately selecting the first time period and the second time period, the short-circuit current (as the sum of the coil short-circuit currents flowing respectively) can be adjusted such that a larger current component is obtained in the direction of the propulsive force (i.e., in the q direction in the dq coordinate system of the Cartesian field orientation). Thereby, the part of the short-circuit current that resists the field direction for the propulsive movement is increased, thereby achieving a greater braking effect compared to the case of a persistent short circuit, and thereby causing the transmission unit to stop faster. Therefore, even in the case of a relatively small short-circuit current, a high braking force and thus a better and faster braking of the transmission unit are achieved. In addition, a lower current load and a lower field weakening are achieved. Furthermore, the lower field weakening causes a lower reduction in the normal force, thereby in some cases additionally avoiding the transmission unit from lifting from the transmission area at a certain speed, especially when the moving direction is curved.

[0058] Advantageously, the total short-circuit current flowing through the drive coil is determined, and the target short-circuit current with the maximum short-circuit current component icq that forms the propulsive force is determined by means of a predetermined relationship. In the adjusted short-circuit mode, in the short-circuit phase in which the short-circuit current is less than the target short-circuit current, at least a part of the drive coil can operate in the short-circuit state. In the idling phase in which the short-circuit current reaches or exceeds the target short-circuit current, at least a part of the drive coil can operate in the idling state.

[0059] However, in the adjusted short-circuit mode, in the short-circuit phase in which the short-circuit current is less than the target short-circuit current multiplied by a factor, at least a part of the drive coil can also operate in the short-circuit state. In the mixed phase in which the short-circuit current is equal to or exceeds the target short-circuit current multiplied by a factor, at least a part of the drive coil alternately operates in the short-circuit state and in the idling state. In the idling phase in which the short-circuit current is equal to or exceeds the target short-circuit current multiplied by the term (2 minus the factor a), at least a part of the drive coil operates in the idling state.

[0060] Preferably, the predetermined relationship corresponds to f: where Ψ corresponds to the main magnetic flux, and L corresponds to the unsaturated inductance, and this relationship can be derived from the stator voltage equation in the case of a polyphase power supply.

[0061] In the mixed phase, at least a part of the drive coil can each alternately operate in the short-circuit state on the short-circuit section and in the idling state on the idling section, where the duration of the short-circuit section is determined relative to the duration of the idling section and is advantageously calculated by means of a third-order polynomial with an error deviation.

[0062] Furthermore, a factor of 0.85 can be selected, which results in a particularly good braking effect, as has been confirmed in practice.

[0063] It is completely particularly advantageous to switch only the drive coils magnetically coupled to the transport unit to a regulated short-circuit mode. Thereby, it is not necessary to switch all drive coils of the entire electromagnetic transport system to the short-circuit mode. Thus, for example, only one transport unit can be braked as required, while other transport units are not affected by the braking process.

[0064] For this purpose, a position sensor can be used to determine the drive coils magnetically coupled to the transport unit. This can be advantageous if a position sensor is already provided on the electromagnetic transport system.

[0065] However, the drive coils magnetically coupled to the transport unit can also be identified by the coil short-circuit current induced in the corresponding drive coils. The induced coil short-circuit current indicates magnetic coupling with the transport unit.

[0066] Of course, other drive coils (for example, a certain number of drive coils located in front of the transport unit in the direction of movement) can also be switched to a regulated short-circuit mode as desired.

[0067] The duration of the braking process depends, in addition to the selection of the first and second time periods, on the mass of the transport unit (as well as on the additional mass combined with the transport unit (the goods being transported, workpieces, etc.)) and / or the speed of the transport unit. The energy released during the braking process is mainly converted into heat in the winding resistance (copper losses) and the iron core (mainly eddy current losses).

[0068] For different designs of the control unit, short-circuiting can mean different switching settings. If the control unit has a full bridge with four switches per drive coil each (as in US 2006 / 0220623 A1), then it can be switched to full short-circuit during the regulated short-circuit in the short-circuit phase or short-circuit interval. However, if the control unit has a half bridge including one upper switch and one lower switch per drive coil (see AT 518 721 A1), then the short-circuit is modulated in the short-circuit phase or short-circuit interval. This means that the upper switch of the half bridge and the lower switch of the half bridge are alternately turned on, preferably in a 50 / 50 ratio. However, the upper switch and the lower switch cannot be turned on simultaneously here.

[0069] In a design related to the operation of a drive coil, the safety module can access the control unit of the electromagnetic transmission system or can also be part of the control unit. Here, for example, the requirements of a predetermined safety requirement level are also to be met in the form of a redundant design of the control unit. It can also be stipulated that the drive coils are controlled alternately by different control units. Thus, in the event of a malfunction of a control unit, another non-faulty control unit can continue to set the short circuit and / or idling of the drive coil.

[0070] In the transmission area, a plurality of safety areas with associated safety functions can also be provided. The safety functions can each be permanently activated or activatable by a safety state, where the transmission area can include permanently activated and activatable safety functions. Of course, the safety functions of the transmission area can also be implemented differently (for example, each by a braking element and / or a blocking element and / or a deflecting element, etc.).

[0071] In the safety areas of the transmission area, a plurality of safety functions that are each permanently activated and / or activatable can also be provided. This can also be interpreted as overlapping individual safety areas. The safety functions of the safety areas can also be implemented differently (for example, each by a braking element and / or a blocking element and / or a deflecting element, etc.). Description of the Drawings

[0072] In the following, the present invention will be explained in more detail with reference to FIGS. 1 to Figure 9 and more particularly, FIGS. 1 to Figure 9 exemplarily, schematically and non - restrictively show advantageous design configurations of the present invention. Shown in the drawings are:

[0073] Figure 1a A long - stator linear motor with safety areas is shown,

[0074] Figure 1b A planar motor with safety areas is shown,

[0075] Figure 2a a, b show safety blocking elements in a long - stator linear motor,

[0076] Figure 2c c, d show safety blocking elements in a planar motor,

[0077] Figure 3a a, b show safety deflecting elements in a long - stator linear motor,

[0078] Figure 3c c, d show safety deflecting elements in a planar motor,

[0079] Figure 4a A full - bridge for controlling a drive coil is shown,

[0080] Figure 4bShows a half-bridge for controlling a drive coil,

[0081] Figure 5 Shows the short-circuit current forming torque, the short-circuit current forming a field, and the time profile of the short-circuit current, which are formed by a combination of multiple overlapping coils,

[0082] Figure 6 Shows an approximation of the braking force due to the short-circuit current,

[0083] Figure 7 Shows typical switching patterns for the short-circuit section and the idling section,

[0084] Figure 8a And b show the profiles of the short-circuit section with respect to the short-circuit current and the error deviation,

[0085] Figure 9 Shows the time profiles of the first and second short-circuit currents and the first and second generated braking forces of multiple drive coils. Detailed Description

[0086] Figure 1a Shows a simple example of a long-stator linear motor as the electromagnetic transmission system 2. The long-stator linear motor has a closed transmission path as the transmission area 20. On the transmission path, multiple (m) drive coils Sm are successively arranged in the moving direction w of the transmission unit 1. These drive coils Sm are each supplied with a coil current i m for power supply to generate a moving magnetic field. Here, the arrow marked with i m is of course only shown schematically. The drive coils Sm can also be connected to the control unit 4 in other ways to supply the drive coils Sm with a coil current i m for power supply. The control unit 4 can be implemented as suitable hardware and / or as software running on suitable hardware.

[0087] The drive coils Sm arranged adjacent to each other in the moving direction w are arranged on a fixed holding structure 3 (only shown in FIG. 1) on the transmission path. The transmission unit 1 moves along the transmission path in the moving direction w and is accordingly guided and held on the fixed transmission path in a suitable manner.

[0088] The transport unit 1 has a first magnet M1 arranged laterally along the direction of movement w and may also have a magnet M2 arranged laterally, as shown in FIG1 , which may be located opposite the first magnet M1 in a transverse direction transverse to the direction of movement w. If the transport unit 1 has a first magnet M1 or a second magnet M2 on both sides, drive coils Sm may be provided on both sides of the transport path (as viewed in the direction of movement w) to facilitate movement of the transport unit 1. Preferably, the control unit 4 only supplies power to the drive coils Sm in the region of the magnets M1 and M2 for movement, which may also include drive coils Sm located before and / or after the transport unit 1. Of course, more than one transport unit 1 may also be movable along the transport path, with each transport unit 1 being able to move independently of the other transport units 1 (in terms of direction, position, velocity, and acceleration) by supplying power to the drive coils Sm in the region of the transport unit 1. In order to determine the position of the transmission unit 1 on the stator and thus the coil Sm currently to be supplied and situated on the transmission unit 1 along the transmission path, a current sensor can be provided, for example.

[0089] The transfer path can be shaped arbitrarily depending on the application and requirements and can include closed and / or open path sections. The transfer path does not necessarily lie in a plane but can also be arbitrarily directed in space. A transfer path typically consists of a plurality of combined transfer sections, each with a number of drive coils Sm. Similarly, bifurcations are known to guide the transfer unit 1 from a first transfer path to a second transfer path.

[0090] Figure 1b A simple example of an electromagnetic transmission system 2 is shown as a planar motor. The planar motor has a transmission plane as a transmission region 20. A plurality (m) of drive coils Sm are arranged in the transmission plane, which is provided as an xy plane. The drive coils Sm are arranged only by way of example along the x-axis and the y-axis and, in normal operation, are each driven with a coil current i under the control of a control unit 4 (only some of the drive coils Sm are shown). m The drive coil Sm can also be connected to the control unit 4 in other ways so that the coil current i m The control unit 4 may be implemented as appropriate hardware and / or as software running on appropriate hardware.

[0091] The drive coil Sm generates a magnetic field in the transport plane to move the transport unit 1 in this transport plane. For this purpose, the transport unit 1 has magnets M3, M4 arranged preferably parallel to the drive coil Sm. In the illustrated embodiment, the magnet M3 is arranged along the x-axis, while the magnet M4 is arranged along the y-axis. Preferably, in order to move the transport unit 1, only the control unit 4 supplies power to the drive coil Sm in the region of the magnets M3, M4, where this region may also include drive coils Sm located in front of and / or behind and / or to the side of the transport unit 1. By appropriately controlling the drive coil Sm, the transport unit 1 can also be moved in a movement direction w along one of the axes not parallel to the transport plane, as is also shown in the drawing. Of course, more than one transport unit 1 can also be moved in the transport plane, where each transport unit 1 can be moved (in terms of direction, position, speed, and acceleration) independently of the other transport units 1 by correspondingly supplying power to the drive coil Sm in the region of the transport unit 1. In order to determine the position of the transport unit 1 in the transport plane and thus the coil Sm currently to be energized at the location of the transport unit 1 in the transport region 20, a current sensor can be provided, for example. The transport plane can be shaped arbitrarily according to the application and requirements and can also be guided arbitrarily in space. Furthermore, the transport plane is usually composed of a plurality of transport segments arranged adjacent to each other.

[0092] In a known manner by the drive current i A The current component iq (q-component) of the drive current i that forms the propulsive force forms the propulsive force required for the movement of the transport unit 1 of the electromagnetic transport system 2. The drive current i A corresponds to the vector total current of all the coil currents i of the drive coil Sm acting on the transport unit 1 m .

[0093] If a long-stator linear motor is provided as the transport system, the drive current is a current vector having q and d components (the current component forming the normal force). If a planar motor is provided as the transport system, the drive current is a current vector having two q components and one d component (the current component forming the normal force).

[0094] Therefore, for the normal forward movement of the transport unit 1, the current component iq (q-component) that forms the propulsive force is sufficient. The normal force not used for forward movement is formed by the current component id (d-component) of the drive current i A that forms the normal force.

[0095] In a long-stator linear motor or a planar motor, a plurality of drive coils Sm usually act on the transport unit 1 simultaneously to achieve movement in the movement direction w at a speed v. If there is no d-component, the current component iq that forms the propulsive force corresponds to all the coil currents i of the drive coil Sm acting on the transport unit 1 mThe total vector current. Thus, as is well known, the current component iq that forms the driving force calculated in the control unit 4 still has to be converted into the actual effective coil current i of the drive coil Sm m and is shunted and applied thereto.

[0096] In the transport region 20, a safety region S is provided in the transport direction w in front of the transport unit 1. The safety region 20 can be fixedly arranged in the transport region 20 and, for example, comprises a transport section of the transport region 20. Of course, it is also possible that the safety region S comprises a fixedly pre-given or flexibly determined part of the transport region 20 before or after a transport section, or only starts after a fixedly pre-given or flexibly determined distance before or after the transport section.

[0097] In the case of a planar motor as the electromagnetic transport system 2, the safety region S can also enclose the specified working region in which the transport unit 1 is allowed to move. Thereby, it is possible to prevent the transport unit 1 from moving out of the transport plane.

[0098] Compared with the non-safety region, the safety region can also have different restrictions: different maximum speeds, different maximum currents, different minimum distances between round trips.

[0099] The safety region S can also depend entirely on the position of the transport unit 1. Thus, a safety deceleration region V of the transport unit 1 can be provided, where the safety region S starts after the safety deceleration region V. Similarly, the safety region S can also depend on the position of a person.

[0100] If a long-stator linear motor is provided as the electromagnetic transport system 2, the safety region S can be regarded as a section of the transport path, as Figure 1a shown. If a planar motor is provided as the electromagnetic transport system 2, the safety region S can be regarded as a flat sub-region of the transport plane, as Figure 1b shown.

[0101] As a hybrid form, the safety region S can in principle also depend on the position of the transport unit 1, but is determined with regard to the characteristics of the transport region 20. Thus, for example, a transport section located in front of the transport unit 1 in the transport direction w (for example, the next transport section located in front of the transport unit 1 in the transport direction w) can be defined as the safety region S. Thereby, the safety position S depends on the position of the transport unit 1 and the arrangement of the transport section. Here, the safety region S can also comprise a fixedly pre-given or flexibly determined part of the transport region 20 before or after a transport section that is located in front of the transport unit 1 in the transport direction w. Similarly, the safety region S can only start after a fixedly pre-given or flexibly determined distance before or after a transport section that is located in front of the transport unit 1 in the transport direction w.

[0102] According to the present invention, a safety module M for implementing a safety function is provided. The safety module M or the safety function ensures, according to an embodiment, that the transmission unit 1 reaches the safety area S at a speed v less than or equal to the safety speed v_S according to a predetermined safety requirement level (SIL), or avoids the transmission unit 1 reaching the safety area S according to a predetermined safety requirement level. The safety function may be permanently activated. For example, in the illustrated embodiment, the safety function is activated by triggering the safety state N.

[0103] The transmission unit 1 moving at a speed v has a corresponding momentum due to its mass m, which results in a driving force. If the speed v is less than or equal to the safety speed v_S, then this momentum is also less than or equal to the safety momentum, and when the transmission unit 1 interacts with an object or a body, this driving force is less than or equal to the safety driving force. The transmission unit 1 is driven by an electric motor driving force F m which is m obtained from the product of the current component iq forming the propulsion force and the constant ki. Other forces (e.g., frictional force F f , gravitational force F g , etc.) may also act on the transmission unit 1, and the sum of these forces gives the total force F t acting on the transmission unit 1. The movement formula of the transmission unit 1 moving without interference can be shown, for example, as follows: m*a = F t = F m - F g - F f , where the sum of the electric motor driving force F m , gravitational force F g and frictional force F f can be regarded as the transmission unit force F1. If the transmission unit 1 comes into contact with an object or a body (e.g., due to a collision), then the interaction force F e also acts on the transmission unit 1 in addition, and thus the movement formula is m*a = F t = F m - F g - F f - F e = F1 - F e . The interaction force F e can be modeled as F e = -k e x e using the penetration depth x e of the object or the body and the spring stiffness k e . In order to be able to limit the interaction force F e (and thus the penetration depth x e) The speed v can be limited to a value less than or equal to the safety speed v_S. However, a limitation can additionally or alternatively be imposed such that the transmission unit force F1 is less than the safety force F_S. Similarly, the transmission unit energy E1 (transmission unit kinetic energy) (m*v2 / 2) of the transmission unit is limited to a value less than or equal to the safety energy E_s. Thereby, the interaction energy acting on the transmission unit is restricted.

[0104] The arrival of the transmission unit 1 at the safety region S can be prevented by means of a blocking element X (Figure 2) arranged on the transmission unit 1 and / or in the transmission region 20 and / or by means of a deflection element U (Figure 3) arranged on the transmission unit 1 and / or in the transmission region 20.

[0105] Figure 2a 、b and Figure 3a 、b relate to a long-stator linear motor as the electromagnetic transmission system 2, where the transmission path serves as the transmission region 20. Here, only a section of the transmission path is shown, in which a safety region S is provided in front of the transmission unit 1 in the moving direction w.

[0106] Figure 2c 、d and Figure 3c 、d relate to a planar motor as the electromagnetic transmission system 2, where the transmission plane serves as the transmission region 20. Here, only a section of the transmission plane is shown, in which a safety region S is provided in front of the transmission unit 1 in the moving direction w.

[0107] In Figure 2a 、b、c、d, the safety module M includes a blocking element X. In Figure 2a and 2c the safety state N is not triggered, so the blocking element X is in the rest position. The rest position is not in the moving direction w and thus does not block the transmission unit 1, whereby the transmission unit 1 can move forward unhindered in the moving direction w. In contrast, in Figure 2b and 2d the safety state N is triggered and thus the safety function is activated, so the blocking element X is brought to the blocking position, which is in front of the safety region S in the moving direction w in the transmission region 20 from the perspective of the transmission unit 1. Thereby, the transmission unit 1 is physically prevented from entering the safety region S and instead is blocked and stopped by the blocking element X even before reaching the safety region S. Here, it is important that this blocking is ensured by the safety module M and the blocking element X it includes in accordance with a predetermined safety requirement level.

[0108] The blocking element X can be moved into the transport area 20 from the side in the direction of movement w, but can also be moved into the transport area 20 from above or below and moved in the direction of movement w, or moved out of the transport area 20 in the direction of movement w. Similarly, the blocking element X can be arranged on the transport unit 1 itself (for example, in the form of a retractable grappling hook, a device for increasing the mechanical width, a device that blocks the transport unit 1 in the transport area 20, etc.).

[0109] In Figure 3a , b, c, d, the safety module M includes a deflection element U. In Figure 3a and 3c , the safety state N is not triggered, and thus the safety function is not activated, so the deflection element U is in the rest position. This rest position is located away from the direction of movement w, so that the transport unit 1 can also move forward unhindered in the direction of movement w. However, in Figure 3b and 3d , the safety state N is triggered, and thus the safety function is activated, so the deflection element U is brought to the deflection position, which is in front of the safety area S in the direction of movement w in the transport area 20. The transport unit 1 is deflected from the direction of movement w by the deflection element U in the deflection position. Thereby, physically preventing the transport unit 1 from entering the safety area S. Here, it is also important that this deflection is ensured by the safety module M and the deflection element U it includes according to a predetermined safety requirement level.

[0110] The deflection element U does not have to absorb as high a kinetic energy of the transport unit 1 as in the case of the blocking element X, because the deflection element U does not completely stop the transport unit 1. Therefore, the deflection element U can be used especially in the case of a transport unit 1 with or expected to have a high speed v.

[0111] In a long-stator linear motor as the electromagnetic transport system 2, a switch already provided on the transport path can be used as the deflection element U, whereby the transport unit 1 is deflected into an alternative part of the transport path 20' that does not have the safety area S, as also shown in Figure 3b .

[0112] The blocking element X and / or the deflection element U are preferably fixedly arranged in the transport area 20, but can also be movably arranged in the transport area 20, and thereby also ensure a variable (i.e., non-fixed) safety area S. The blocking element X and the deflection element U are used especially in front of a safety area S where high safety requirement levels must be met.

[0113] Of course, it is also conceivable that the safety module M includes one or more deflection elements U and one or more blocking elements X. The deflection elements U and the blocking elements X can also be used with respect to the safety area S in the following manner: The transport unit 1 is deflected before reaching the safety area S and is subsequently blocked by the blocking element X. In the case of a sufficient coasting time after the transport unit 1 has been deflected by the deflection element U, it can be ensured that the transport unit 1 has a lower kinetic energy when the transport unit 1 is subsequently blocked by the blocking element X than in the case of an immediate blockage.

[0114] The safety module M can include a braking element E arranged on the transport unit 1 and / or in the transport area 20. The braking element E can be designed, within the scope of the safety function (for example, after activating the safety function by triggering the safety state N), to ensure that the movement of the transport unit 1 is braked with a predetermined safety requirement level, such that the transport unit 1 reaches the safety area S at a speed v that is less than or equal to the safety speed v_S, or to ensure that the transport unit 1 stops before reaching the safety area S. The braking element E must be implemented and dimensioned according to a predetermined safety requirement level.

[0115] The braking element E can act mechanically on the transport unit 1, for example, by increasing the frictional force between the transport unit 1 and the transport area 20. This can be achieved, for example, by providing a surface with a high coefficient of friction in the transport area 20 and / or by actively increasing the normal force acting on the transport unit 1.

[0116] The braking element E can also act magnetically on the transport unit 1. Thus, for example, a magnet unit or an iron unit can be provided to decelerate the transport unit 1 by magnetic force action.

[0117] Therefore, the braking element E can use any acting mechanism for force transmission to the transport unit 1. For example, an increased air resistance can also be used (for example, by blowing compressed air) to brake the transport unit.

[0118] The acting mechanisms for force transmission mentioned in connection with the blocking element E can also be used in the deflection element U to deflect the transport unit 1.

[0119] The safety function can also ensure that at least a first part of the drive coil Sm operates in a short-circuit state for at least a period of time within the scope of the safety function (for example, after activating the safety function by triggering the safety state N). The safety function can also ensure that at least a second part of the drive coil Sm operates in an idling state for at least a period of time within the scope of the safety function (for example, after activating the safety function by triggering the safety state N). This is particularly advantageous in combination with one or more of the designs mentioned herein (braking element E, blocking element X, deflection element U).

[0120] Not only for operation in the short - circuit state, but also for operation in the idling state corresponding to the safety function, it must be ensured with the corresponding specified safety requirement level. More precisely, it is ensured that the transport unit 1 reaches the safety area S at a speed v less than or equal to the safety speed v_S, or the transport unit 1 is prevented from reaching the safety area S. For this purpose, the safety function or the safety module M can access the control unit 4 or can also be part of the control unit 4.

[0121] Within the scope of the safety function, the transport unit 1 can be enabled to brake completely before reaching the safety area S or to brake at the safety speed v_S until reaching the safety area S by short - circuiting, for example, the corresponding drive coil Sm or all drive coils Sm that interact with the transport unit 1 or, for example, the drive coils Sm arranged in the moving direction w. For this purpose, for example, the control unit 4 positions the switches of the full - bridge VB / half - bridge HB in a suitable position, which can be initiated, for example, by a short - circuit regulator belonging to the safety module M. Of course, the short - circuit can also be generated in other ways (for example, by a switch in parallel with the drive coil Sm). When a full - bridge is used in the control unit 4, "short - circuit" means a complete short - circuit.

[0122] Particularly advantageously, within the scope of the safety function (for example, during activation of the safety function by triggering the safety state N), at least a part of the drive coil Sm operates in the short - circuit state at least for a first time period, and particularly advantageously, at least a part of the drive coil Sm operates in the idling state at least for a second time period to generate a regulated short - circuit. Thereby, a particularly efficient braking process of the transport unit 1 can be generated.

[0123] Figure 4a Shows for the coil current i mFull bridge VB for supplying power to drive coil Sm. The drive coil Sm has a first coil connection Sm1 and a second coil connection Sm2. The full bridge VB consists of two main branches, where the first main branch consists of two switches S11, S21, which are connected in series at the operating voltage Ub, and the operating voltage Ub is formed at the inlet connection of the full bridge VB by the difference between the first operating potential Ub1 and the second operating potential Ub2. The second main branch also consists of two switches S11', S21' connected in series at the operating voltage Ub. The first lateral connection Q1 of the lateral branch is located between the connection points of the first switch S11 and the second switch S21 of the first main branch. Equivalently, the second lateral connection Q2 of the lateral branch is located between the connection points of the first switch S11' and the second switch S21' of the second main branch. The first coil connection Sm1 of the drive coil Sm is connected to the first lateral connection Q1, and the second coil connection Sm2 of the drive coil Sm is connected to the second lateral connection Q2. By appropriately controlling the switches S11, S21, S11', S21' by the control unit 4 (not shown here), the same potential can be applied between the first coil connection Sm1 and the second coil connection Sm2 during the flow of the coil current i m During the flow, the same potential is applied between the first coil connection Sm1 and the second coil connection Sm2. Therefore, in the case of a complete short circuit, the switches S11 and S11' are turned on (in the case of the open switches S21 and S21'), or the switches S21, S21' are turned on (in the case of the open switches S11, S11').

[0124] The half bridge HB can also be controlled by the control unit 4 to supply power to the drive coil Sm with the coil current i m For example, as shown in Figure 4b Shown. Here, the second main branch of the full bridge VB is omitted, and thus the operating voltage Ub is applied only on the first main branch between the first inlet connection A1 and the second inlet connection B1 and on the first switch S11 and the second switch S21 connected in series therebetween. The connection point between the first switch S11 and the second switch S21 is called the midpoint C1 and is connected to the first connection Sm1 of the drive coil Sm. The second connection L12 of the drive coil Sm is at a potential Ux pre-given, for example, by a potential regulating unit, at the regulating point C. All second connections Sm2 of the drive coil Sm (not shown here) are usually connected to the regulating point C and are regulated to the potential Ux, which usually corresponds to half of the operating voltage Ub.

[0125] In the case of using a half-bridge HB, it is impossible to directly short-circuit the drive coil Sm through two switches S11 and S12 because switches S11 and S21 cannot be closed simultaneously. Therefore, in order not to short-circuit the operating voltage Ub, "PWM short-circuit" is provided when using the half-bridge HB. PWM short-circuit means that the upper switch S11 and the lower switch S21 of the half-bridge HB are each alternately switched, for example, with a 50 / 50 clock timing over a period T. Thus, the same potential Ux exists on both connectors Sm1, Sm2 of the drive coil Sm - similar to Figure 4a the full-bridge VB shown, where in the case of a complete short-circuit, the two coil connectors Sm1, Sm2 are at a first operating potential Ub1 or a second operating potential Ub2. When switching the closed / open switches of the half-bridge HB, the minimum protection time can be observed to eliminate any possible residual charge.

[0126] PWM short-circuit does not correspond to a complete short-circuit at any point in time, but can be interpreted as a short-circuit with respect to the time integral of the coil voltage over one switching cycle. Here, the drive coil Sm involved is of course no longer supplied with coil current i m by the regulating unit R. However, in the drive coil Sm coupled to the transmission unit 1, due to further movement in the movement direction w, coil short-circuit currents icm are respectively generated due to the voltage induced by the EMF (electromagnetic force).

[0127] Because the stator current i A (in the dq coordinate system) corresponds to the vector total current of all coil currents i m , it follows that the short-circuit current ic (in the dq coordinate system) is the vector sum of the coil short-circuit currents icm. Figure 5 The time profile of the short-circuit current ic in the case of continuous short-circuit during the braking process is shown. It can be seen that starting from the braking time point O, the short-circuit current ic initially has the conventional profile of the short-circuit current ic of the stator with an oscillatory behavior. Therefore, after the subtransient profile, a transient profile appears, followed finally by an approximately constant profile that eventually decreases and tends to zero. This decrease is caused by the reduction of the driving electromagnetic force (EMF) because the speed of the transmission unit 1 is already very low at this time point.

[0128] Similarly, in Figure 5Also depicted therein are the short - circuit current component icq that forms the driving force for the short - circuit current ic and the trend of the short - circuit current component icd that forms the field (i.e., shown in the field direction). Here, the short - circuit current component icq that forms the driving force is responsible for braking the transmission unit 1 in the same way as the current component iq that forms the driving force is responsible for moving the transmission unit 1 in the moving direction w during normal operation. Therefore, it is desirable to additionally increase or maximize the short - circuit current component icq that forms the driving force during the regulated short - circuit mode K. The increase in the short - circuit current component icq that forms the driving force is carried out by a suitable selection of the short - circuit phase and the idling phase.

[0129] An estimate of the relationship of the current component iq that forms the driving force to the total short - circuit current ic can be formed without additional information about position or angle. For this purpose, the stator voltage formula formed for a poly - phase power supply is assumed. The stator equation is solved according to the speed and a stationary case is assumed (i.e., not changing with time, which in turn means the speed is zero). Considering the relationship the stator equation is solved according to . The magnetic flux Ψ of the permanent magnet can be assumed to be approximately constant. Using the relationship thus determined in the force equation, the force equation is then derived from the short - circuit current ic. Setting the derived force equation to zero corresponds to the optimal relationship of the total short - circuit current ic derived from the current component iq that forms the driving force, i.e., maximizing the current component iq that forms the driving force. Thus, the relational formula f for the optimal target short - circuit current ic_soll can be derived:

[0130] Therefore, the optimal target short - circuit current ic_soll with the maximum short - circuit current component icq that forms the driving force can be determined from the stator voltage formula according to the relational formula f: to be determined.

[0131] The corresponding values of the inductance L and the magnetic flux Ψ can be determined, for example, by experiments.

[0132] In Figure 6 the approximate relationship of the braking force Fb for a certain speed of the transmission unit 1 to the short - circuit current ic is shown, where the short - circuit current ic is plotted on the abscissa and the effective braking force Fb is plotted on the ordinate. Similarly, the optimal target short - circuit current ic_soll is shown and represents the short - circuit current ic that gives the maximum braking force Fb, because this maximizes the short - circuit current component icq that forms the driving force.

[0133] In order to determine the actual short - circuit current ic at the start of the braking process and in each cycle after the start of the braking process, all drive coils Sm, segmented drive coils Sm, or only the drive coils Sm coupled to the transmission unit 1 (as long as known) can be short - circuited for a short period of time. The short - circuit current ic can be calculated as the vector sum of the measured coil short - circuit current icm.

[0134] Figure 7 A typical period T is shown in which the short - circuit interval tc_ks and the idling interval tc_ll alternate. Here, for example, it is assumed that the period T is constant, but of course it can also be changed.

[0135] When using the full - bridge VB (see Figure 2a ), the switches S11, S21, S11', S21' are opened in the idling interval tc_ll, and in the short - circuit interval tc_ks, the switches S21 and S21' or the switches S11 and S11' are closed for complete short - circuit. In the idling interval tc_ll, all four switches S11, S21', S11', S21 of the full - bridge VB are opened. When using the half - bridge HB (see Figure 2b ), the switches S11 and S21 are opened in the idling interval tc_ll, and in the short - circuit interval tc_ks, they are alternately closed (e.g., in a 50 / 50 ratio).

[0136] As a limiting case, it can be conceived that the short - circuit interval tc_ll is zero (i.e., the idling interval tc_ll is equal in magnitude to the period T) or the short - circuit interval tc_ll is equal in magnitude to the period T (and thus the idling interval tc_ll is zero). However, especially in the case of PWM short - circuit of the half - bridge HB, the short - circuit interval tc_1l should preferably not be zero, but just above zero, preferably the minimum protection time.

[0137] The correct ratio of the short - circuit interval tc_ks to the idling interval tc_ll can be selected with the aid of a short - circuit regulator K, which can be connected upstream of the regulating unit R (as shown in FIG. 1) or can be an integral part of the regulating unit R.

[0138] Advantageously, there are three phases A, B, and C in the regulated short - circuit mode K. In the short - circuit phase A, in which the short - circuit current ic is less than the target short - circuit current ic_soll multiplied by the factor a (ic < ic_soll·a), at least a part of the drive coil Sm interacting with the transmission unit 1 operates in the short - circuit state for each cycle duration T (i.e., continuously), because the actual short - circuit current ic is less than the target short - circuit current ic_soll. This can mean a complete short - circuit when using the full - bridge VB in the control unit 4, or "PWM short - circuit" when using the half - bridge HB in the control unit 4. This means that in the short - circuit phase A, within each cycle duration T, the short - circuit interval tc_ks is maximized and the idle interval ic_ll is minimized. Here, the short - circuit interval tc_ks can extend over the entire cycle duration T, whereby the idle interval tc_ll is zero. In principle, a minimum duration of the idle phase tc_ll (i.e., a maximum duration of the short - circuit phase tc_ks) can be provided for the short - circuit phase A, and this minimum duration can correspond to a predefined minimum protection time. For example, for a cycle duration T of 25 μs, the minimum duration of the idle phase tc_ll corresponds to a predefined minimum protection time (e.g., 500 ns).

[0139] In the hybrid phase B, in which the short - circuit current ic is equal to or exceeds the target short - circuit current ic_soll multiplied by the factor a (ic ≥ ic_soll·a) and advantageously less than the target short - circuit current ic_soll multiplied by (2 - a) (ic < ic_soll·(2 - a)), at least a part of the drive coil Sm operates alternately in the short - circuit state and in the idle state. This means that the short - circuit interval tc_ks and the idle interval tc_ll alternate within the cycle T. In particular, the respective durations of the short - circuit interval tc_ks and the idle interval tc_ll within the cycle T for the hybrid phase B can be calculated by means of a third - order polynomial with an error deviation e_ic. The error deviation e_ic represents the deviation of the short - circuit current ic from the target short - circuit current ic_soll.

[0140] In the idle phase C, in which the short - circuit current ic is equal to or exceeds the target short - circuit current ic_soll multiplied by the term (2 - a) (ic ≥ ic_soll·(2 - a)), at least a part of the drive coil Sm operates in the idle state. The control unit 4 maximizes the idle interval tc_ll and minimizes the short - circuit interval tc_ks. Here, the idle interval tc_ll can extend over the entire cycle duration T, whereby the short - circuit interval tc_ks is zero. However, the minimum short - circuit interval tc_ks can also be set to be greater than zero or the maximum idle interval tc_ll can be set to be less than the cycle duration T. For example, if the factor a is chosen to be zero, only the hybrid phase B is applied.

[0141] For example, if the selection factor a is 1, then the operation in short - circuit phase A is carried out when the short - circuit current ic is less than the target short - circuit current ic_soll, and the operation in the idling phase C is carried out when the short - circuit current ic is equal to or greater than the target short - circuit current ic_soll. Correspondingly, in this particular case, there is no hybrid phase B.

[0142] The factor a can be predetermined or pre - given, and it has been proven that a factor of a = 0.85 is particularly advantageous for the short - circuit current regulation of the electromagnetic transmission system. For the factor a = 0.85, the boundary from the idling phase A to the hybrid phase B is shown as a dashed line in FIG. 8, and the boundary from the hybrid phase B to the short - circuit phase C is also shown.

[0143] Advantageously, in the hybrid phase B, at least a part of the drive coil Sm alternately operates in the short - circuit state on the short - circuit interval tc_ks and in the idling state on the idling interval tc_ll, where the duration of the short - circuit interval tc_ks is determined relative to the duration of the idling interval tc_ll.

[0144] In Figure 8a the course of the short - circuit current ic on the idling phase tc_ll is shown, where the transition is made from the short - circuit phase A via the hybrid phase B to the idling phase C. Here, the idling interval tc_ll itself is not completely zero in the short - circuit phase A because there is a minimum duration set for the idling phase tc_ll. In Figure 8b the course of the error deviation e_ic with respect to the idling phase tc_ll from the idling phase C via the second phase B to the first short - circuit phase A is shown. Since a third - order polynomial is used to calculate the idling interval tc_ll and the short - circuit interval tc_ks in the hybrid phase B for the error deviation e_ic, a smooth transition into or out of the hybrid phase B can be achieved for the short - circuit current ic, whereby the noise of the short - circuit current ic can be kept low. Alternatively, it is also possible that there is no hybrid phase B and a hard switch is made from the short - circuit phase A to the idling phase C, and vice versa.

[0145] In Figure 9 the time courses of the first short - circuit current ic1 for a permanent or 50 / 50 PWM short - circuit and the second short - circuit current ic2 generated according to the invention are shown. The maximum short - circuit phase tc_ks is selected for the first short - circuit current ic1, i.e., the persistent phase A. In Figure 9The time profiles of the first braking force Fb1 derived from the first short-circuit current ic1 and the second braking force Fb2 derived from the second short-circuit current ic2 are shown in the lower part. It can be seen that the second braking force Fb2 is higher than the first braking force Fb1 especially immediately after the start of the braking process, although the second short-circuit current ic2 is smaller than the first short-circuit current ic1. This is due to the increased propulsive short-circuit current component icq according to the invention. In addition, the oscillation behavior of the second short-circuit current ic2 is improved.

[0146] In principle, the selection of the drive coil Sm controlled according to the adjusted short-circuit pattern K can be freely carried out. Thus, all drive coils Sn or a part of the drive coils Sn can be switched to the adjusted short-circuit pattern K. The drive coil Sm magnetically coupled to the transmission unit T1 can advantageously be switched to the adjusted short-circuit pattern K.

[0147] It can be determined via the current position of the transmission unit 1 which drive coils Sm are coupled to the transmission unit 1. This position identification can be carried out by means of a suitable position sensor that may already be provided on the electromagnetic transmission system, for example as described in AT 519238A1.

[0148] However, it can also be recognized which drive coils Sm result in a (measured) coil short-circuit current icm in the short-circuit state. From this, it can be derived which of the drive coils Sm in the drive coils Sm are magnetically coupled to the transmission unit 1.

[0149] If it is recognized that the transmission unit 1 continues to move during the braking process such that another drive coil Sm in the moving direction w is coupled to the transmission unit 1 (for example, because a coil short-circuit current icm is induced), then this drive coil Sm can also be switched to the short-circuit pattern K. This usually results in the drive coils Sm in the direction opposite to the moving direction w no longer being coupled to the transmission unit 1, whereby these drive coils Sm no longer have to be maintained in the short-circuit pattern K. However, it can also be recognized via the position sensor or the non-induced coil short-circuit current icm that the drive coils Sm in the direction opposite to the moving direction w are no longer coupled to the transmission unit 1. It can be recognized that the last coupled drive coil Sm in the direction opposite to the moving direction w is no longer coupled to the transmission unit 1, from which it can be derived that the next coil Sm in the moving direction w runs in the short-circuit pattern K instead of the previously mentioned drive coil Sm.

[0150] Advantageously, the short-circuit current ic can be limited, for example, to a threshold value icmax. This can be carried out by switching from short-circuit to idling. Thus, it is possible to adjust the (average) short-circuit current ic - as long as there is sufficient kinetic energy in the transmission unit 1.

[0151] What all implementations of the described safety functions have in common is that each of these safety functions must meet a predetermined level of safety requirements. The safety functions can be implemented by one or a combination of the following described designs: operation of at least a part of the drive coil Sm in an idling state, operation of at least a part of the drive coil Sm in a short-circuit state, operation of at least a part of the drive coil Sm in a regulated short-circuit state, provision of a braking element E on the transport unit 1 and / or in the transport area 20, provision of a blocking element X on the transport unit 1 and / or in the transport area 20, provision of a deflecting element U on the transport unit 1 and / or in the transport area 20. The same or different safety areas S and the same or different levels of safety requirements can be provided for these measures respectively.

Claims

1. A method for controlling a transmission unit (1) of an electromagnetic transmission system (2), wherein the electromagnetic transmission system (2) comprises a control unit (4) and drive coils (Sm) arranged in a transmission area (20), and wherein the control unit (4) supplies power to the drive coils (Sm) during normal operation to create a magnetic field that can be coupled to the transmission unit (1) and moves in a moving direction (w) in the transmission area (20) so that the transmission unit (1) moves in the transmission area (20) along the moving direction (w). wherein a safety area (S) is provided in the transmission area (20), and wherein a safety function is provided, which ensures that the transmission unit (1) reaches the safety area (S) at a speed (v) less than or equal to a safety speed (v_S) and / or with a transmission unit force (F1) less than or equal to a safety force (F_S) and / or with a transmission unit energy (E1) less than or equal to a safety energy (F_S) in accordance with a predetermined safety requirement level, or avoids the transmission unit (1) reaching the safety area (S).

2. The method according to claim 1, wherein The safety function is activated by triggering a safety state (N).

3. The method according to claim 1, wherein The safety function is permanently activated.

4. The method according to any one of claims 1 to 3, characterized in that, The safety function is implemented at least partially redundantly, and / or the safety function includes a diagnostic function for checking the functionality of the safety function.

5. The method according to claim 4, wherein The safety function is implemented completely redundantly.

6. The method according to claim 1, characterized in that, The safety function meets the safety requirement level 1 according to the standard series IEC 61508.

7. The method according to claim 1, wherein The safety function meets the safety requirements of at least one of the standard series IEC 61508, the standard ISO 13849, and the standard IEC 62061.

8. The method according to claim 1, wherein The safety area (S) is fixedly provided in the transmission area (20).

9. The method according to claim 1, characterized in that, The position of the safety area (S) is dynamically determined in the transmission area (20).

10. The method according to claim 1, wherein A safety deceleration area (V) is provided in front of the transmission unit (1) in the moving direction (w), and the safety area (S) begins after the safety deceleration area (V).

11. The method according to claim 1, wherein, Within the scope of the safety function, at least a first part of the drive coils (Sm) operates in a short-circuit state for at least a period of time.

12. The method according to claim 1, characterized in that, Within the scope of the safety function, at least a second part of the drive coils (Sm) operates in an idling state for at least a period of time.

13. The method according to claim 1, characterized in that, Within the scope of the safety function, at least a third part of the drive coils (Sm) operates in a short-circuit state for at least a first period of time, and at least a part of the drive coils (Sm) operates in an idling state for at least a second period of time.

14. The method according to claim 1, characterized in that, The electromagnetic transmission system (2) is implemented as a long-stator linear motor and / or a planar motor.

15. An electromagnetic transmission system (2), said electromagnetic transmission system (2) comprising a control unit (4), a plurality (m) of drive coils arranged in a transmission area (20), and at least one transmission unit (1), wherein said control unit (4) is designed to supply power to said drive coils (Sm) to create a magnetic field that is coupled to said transmission unit (1) and moves in a moving direction (w) in said transmission area (20) so as to move said transmission unit (1) along said moving direction (w). wherein a safety area (S) is provided in said transmission area (20), and wherein a safety module (M) is provided, said safety module (M) being designed to ensure, in accordance with a predetermined safety requirement level, that said transmission unit (1) reaches said safety area (S) at a speed (v) less than or equal to a safety speed (v_S) and / or with a transmission unit force (F1) less than or equal to a safety force (F_S) and / or with a transmission unit energy (E1) less than or equal to a safety energy (F_S), or to prevent said transmission unit (1) from reaching said safety area (S).

16. The electromagnetic transmission system (2) according to claim 15, characterized in that, Said safety module (M) comprises a braking element (B) arranged on said transmission unit (1) and / or in said transmission area (20), said braking element (B) being designed to ensure, in accordance with a predetermined safety requirement level, that the movement of said transmission unit (1) is braked such that said transmission unit (1) reaches said safety area (S) at a speed (v) less than or equal to a safety speed (v_S) and / or with a transmission unit force (F1) less than or equal to a safety force (F_S) and / or with a transmission unit energy (E1) less than or equal to a safety energy (F_S), or to prevent said transmission unit (1) from reaching said safety area (S).

17. The electromagnetic transmission system (2) according to claim 15 or 16, characterized in that, Said safety module (M) comprises a blocking element (X) arranged on said transmission unit (1) and / or in said transmission area (20), said blocking element (X) being designed to ensure, with a predetermined safety requirement level, that the movement of said transmission unit (1) is blocked so as to prevent reaching said safety area (S).

18. The electromagnetic transmission system (2) according to claim 15, characterized in that, Said safety module (M) comprises a deflection element (U) arranged on said transmission unit (1) and / or in said transmission area (20), said deflection element (U) being designed to ensure, with a predetermined safety requirement level, that the movement of said transmission unit (1) is deflected from said safety area (S) before reaching said safety area (S).

19. The electromagnetic transmission system (2) according to claim 15, characterized in that, Said electromagnetic transmission system is implemented as a long stator linear motor and / or a planar motor.

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