Distance sensor, motion system and method for operating motion system

Abstract

The invention relates to a method for detecting a slider (7; 52) relative to the slider housing (6; 51), having a magnet coil arrangement (23) and a controller (24) electrically connected to the magnet coil arrangement (23), the controller (24) being designed to provide a coil current to the magnet coil arrangement (23), to determine an inductance of the magnet coil arrangement (23), and to process the determined inductance into a distance value, and to periodically evaluate the distance value to determine a relative movement of the slide (7; 52) and / or the speed of the slider (7; 52), and having an electrical interface (25) which is connected to the control unit (24) and which is designed to communicate with a communication subscriber (4) according to a predefined communication protocol.

Description

Technical Field

[0001] The invention relates to a distance sensor, a motion system and a method for operating a motion system. Background Art

[0002] DE 10012830 A1 discloses an electronic proximity switch having a device for generating an electromagnetic alternating field excited by an oscillator, wherein the influence of the alternating field, in particular caused by the approach of a trigger, is evaluated by an electronic signal evaluation stage comprising an amplifier stage for emitting an output signal, and wherein the signal to be evaluated, obtained from the device influenced by the electromagnetic field, is mixed with the oscillator frequency before the evaluation. Summary of the Invention

[0003] The object of the present invention is to provide a distance sensor, a motion system, and a method for operating a motion system, with which a plurality of physical variables can be determined and output.

[0004] According to a first aspect of the invention, this task is solved by a distance sensor for detecting the relative movement of a slider relative to a slider housing, the distance sensor having a magnetic coil device and a controller electrically connected to the magnetic coil device, wherein the controller is designed to provide a coil current to the magnetic coil device, determine the inductance of the magnetic coil device, and process the determined inductance into a distance value, and to periodically evaluate the distance value to determine the speed of the slider and / or the acceleration of the slider, and having an electrical interface, which is connected to the controller and is designed for unidirectional communication with a communication participant according to a predetermined, in particular digital, communication protocol, or the electrical interface is designed for bidirectional communication with a communication participant according to a predetermined, in particular digital, communication protocol.

[0005] The slide and the slide housing form a slide assembly, which can be, for example, an actuator, in particular a linear actuator, or a damping device, in particular a linear damper. The following primarily describes the use of the distance sensor together with the actuator and the damping device; alternatively, the distance sensor can be used only with an actuator or only with a damping device.

[0006] Such distance sensors belong to the category of inductive proximity switches, which are used in practical applications, for example, to output a switching signal when a metal object enters or leaves the detection range of the distance sensor. Changes in the inductance of the magnetic coil arrangement caused by the metal object, which are related to the metal object's relative position with respect to the distance sensor, can be detected and used to output a switching signal when the inductance exceeds or does not exceed a predetermined threshold value. To this end, the inductance is determined in an electrical or electronic controller and processed into a distance value. This distance value represents the distance between the distance sensor and the metal object. This distance value can be compared with a stored threshold value in the distance sensor's controller, and it can be specified that the controller outputs a switching signal as long as the distance value corresponds to the threshold value.

[0007] In the distance sensor according to the present invention, the controller is designed to determine the distance value from the inductance of the magnetic coil arrangement and also to take into account the temporal variation of the distance value in order to determine the speed and / or acceleration of the slider therefrom. The controller, designed as a microcontroller or microprocessor, can include a processor area specifically designed for this purpose for observing the temporal variation of the distance value. Preferably, in addition to the computer program module for determining the distance value, the controller also includes a further computer program module that can evaluate the temporal variation of the distance value.

[0008] The distance values ​​are evaluated cyclically, meaning that changes in the distance values ​​are considered within the same time interval. This corresponds to the time derivative of the distance value. This derivative can also be expressed as ds / dt, where ds is the change in the distance value and dt is the time interval, i.e., the cycle time for the cyclic evaluation. The velocity (v = ds / dt) is obtained by taking the first-order derivative of the distance value with respect to time, and the acceleration (a = dv / dt) is obtained by taking the derivative of the determined velocity with respect to time. If the velocity and / or acceleration do not need to be detected at the maximum resolution of the distance sensor, the distance values ​​can also be considered across multiple identical time intervals. This allows the controller to conserve computing power.

[0009] Furthermore, the distance sensor is equipped with an electrical interface that is connected to a controller and is designed to communicate with one, in particular precisely one (point-to-point), communication participant or with multiple communication participants (multi-pole connection or bus system). The communication participant can be a higher-level controller, such as that provided in a valve island. Such a higher-level controller can be configured to influence the pneumatic or hydraulic valves of the valve island based on the determined speed and / or based on the determined acceleration in order to influence the fluid supply to an actuator comprising a slide and a slide housing. The higher-level controller can also be a motor controller for an electric motor that is a component of the actuator and that is to be supplied with electrical energy based on the determined speed and / or determined acceleration. The higher-level controller can also be a machine controller of a complex system that influences a large number of different processes within the machine or system and processes the speed and / or acceleration provided by the distance sensor.

[0010] The electrical interface can be designed as a discrete component separate from the controller, for example in the form of an electrical or electronic circuit, in particular in the form of a separate microprocessor or microcontroller that communicates with the controller via an internal data connection. The electrical interface can also be designed as an integral component of the controller, in which case it can be provided that the interface functionality is implemented by a computer program module dedicated thereto, which is executed in the controller.

[0011] The electrical interface may be designed only for outputting communication signals, in which case the electrical interface is also referred to as a unidirectional interface. Alternatively, it may be provided that the electrical interface is designed both for outputting communication signals and for receiving communication signals.

[0012] The communication signals output by the interface can be, in particular, speed and / or acceleration and / or status signals, which can, for example, be related to the determined speed and / or acceleration. The communication signals that can be received by the interface can be parameters and / or control signals, which are forwarded via the electrical interface to a controller of the distance sensor in order to thereby influence the mode of operation of the controller.

[0013] The electrical interface can be designed for analog communication, in particular by varying the voltage level, in particular between 0 V and 10 V, or by varying the current level, in particular between 4 mA and 20 mA. If necessary, the electrical interface can be configured to digitally modulate such analog signals in order to be able to transmit additional information, as is the case, for example, with the HART protocol (Highway Addressable Remote Transducer). Alternatively, the electronic interface can be designed for digital communication, for example according to the SPI standard (Serial Peripheral Interface) or other bus protocols.

[0014] Advantageous developments of the invention are the subject matter of the dependent claims.

[0015] It is advantageous if the controller is designed to cyclically evaluate the distance values ​​to determine the velocity and / or acceleration at a repetition frequency greater than 1 kHz, preferably greater than 5 kHz, and in particular greater than 8 kHz. In this case, it is assumed that the controller has an analog circuit for determining the inductance and an analog-to-digital converter for digitizing the determined inductance value, and that the digitized inductance value is subsequently processed by a computer program module running in the controller. Accordingly, the digital components of the controller, such as the analog-to-digital converter and the controller's processor for processing the computer program module, must operate at a clock rate that is at least equal to or greater than the desired repetition frequency for cyclically evaluating the distance values.

[0016] Preferably, the electrical interface is designed for signal output according to the IO-Link standard, or for both signal output and signal reception according to the IO-Link standard. Preferably, the distance sensor's electrical interface is designed as an IO-Link device and is configured to communicate with an IO-Link master. In its simplest configuration, it can be used to output switching signals. To fully utilize the characteristics of IO-Link, the electrical interface provides a rapid sequence of switching signals, which are encoded according to the IO-Link protocol and represent a combination of a data frame and the data packets contained therein. Communication between the IO-Link device and the IO-Link master can be adapted to the communication requirements using parameterization, for example, to adjust the data content to be transmitted and the transmission speed. Alternatively, the distance sensor can be equipped with an electrical interface designed as an IO-Link master and, accordingly, capable of addressing multiple IO-Link devices. This configuration of the electrical interface is particularly interesting when multiple distance sensors are to be connected in a cascaded manner.

[0017] The electrical interface can be used to output signals, in particular measured values ​​such as distance values, speeds, and / or accelerations. Additionally, the electrical interface can also be used to output diagnostic data, status information, and configuration settings that describe fixed, predefined, and / or temporally variable characteristics of the distance sensor.

[0018] During signal reception, a communication participant, such as a higher-level controller, can provide control commands and / or configuration parameters for the distance sensor to the electrical interface, thereby influencing the behavior of the distance sensor. For example, the distance sensor can be placed in a largely inoperative idle state via a control command and then be activated again from the idle state. Furthermore, during signal reception, configuration parameters can also be provided to the distance sensor, such as threshold values, which can be correlated with the determined velocity and / or the determined acceleration.

[0019] It is advantageous if the controller is designed to provide a position-dependent velocity and / or a position-dependent acceleration to the electrical interface. The controller can provide the currently existing velocity value or the currently existing acceleration value to the electrical interface, from which the corresponding value can be forwarded to the communication participants connected to the electrical interface. It is preferably provided that for each velocity value and / or each acceleration value, the controller also provides a position value to the electrical interface, so that the velocity and / or acceleration can be further processed in the connected communication participants in a particularly advantageous manner.

[0020] In a refinement of the present invention, the controller is configured to provide a fault signal when the speed is outside the rated speed range and / or when the acceleration is outside the rated acceleration range, or to provide a function signal when the speed is within the rated speed range and / or when the acceleration is within the rated acceleration range. If the controller is configured to output a fault signal, the determined speed and / or acceleration is also compared with the rated speed range and / or with the rated acceleration range within the scope of the cyclically repeated evaluation of the distance value to calculate the speed and / or acceleration. If the speed is monitored and the determined speed is outside the rated speed range, the controller outputs a fault signal. If the acceleration is monitored and the determined acceleration is outside the rated acceleration range, the controller outputs a fault signal. Similarly, if the determined speed is within the rated speed range and / or the determined acceleration is within the rated acceleration range, the controller may also be configured to output a function signal. For example, it may be provided that the range limits for the rated speed range and / or the range limits for the rated acceleration range are provided as parameters to the controller from the communication participant via the electrical interface within the scope of bidirectional communication.

[0021] In another embodiment of the present invention, the controller is designed to evaluate a velocity profile and / or an acceleration profile in order to determine component load values, in particular actuator or damper load values. This is based on the consideration that, on the one hand, high velocities and accelerations in components such as actuators or dampers require a higher energy input to the actuator or damper than low velocities and accelerations. On the other hand, this also results in greater friction losses for the relative movement between the actuator housing and the slide or between the damper housing and the damper rod, which leads to increased wear. This applies particularly when the slide or damper rod is not braked from rapid movement using pneumatic, hydraulic, or electrical energy, but rather by striking a mechanically acting stop, as this results in particularly high accelerations and, consequently, high wear. To avoid such high loads, the actuator can be equipped with an integrated or external damping device that brakes the slide before it rebounds onto the actuator housing. However, such damping devices are also subject to wear, which is also substantially related to the slide's rebound velocity and the resulting acceleration, in particular, deceleration. The controller may include at least one computer program module that can evaluate velocity and / or acceleration curves and incorporate them into component load values, in particular actuator or shock absorber load values, with which the wear state of the actuator or shock absorber can be modeled. To ensure the most realistic possible modeling of the shock absorber actually used at the actuator, it can be provided, for example, that at least one parameter describing the characteristics of the shock absorber is provided to the computer program module via an electrical interface. Furthermore, a threshold value for evaluating the damping behavior of the shock absorber can also be provided as a parameter to the controller via the electrical interface.

[0022] According to a second aspect of the invention, this object is achieved by a motion system for providing movement, comprising an actuator from the following group: a pneumatic cylinder, a hydraulic cylinder, an electric linear direct drive, an electric threaded spindle drive, an electric toothed belt drive, the actuator comprising an actuator housing and a slide mounted so as to be displaceable relative to the actuator housing, and a distance sensor according to the invention. Preferably, the slide performs a linear relative movement relative to the actuator housing. However, it can also be provided that the slide performs a rotational relative movement (rotational drive, oscillating drive) or a superimposed linear and rotational relative movement relative to the actuator housing.

[0023] One refinement of the motion system provides for a damping device from the following group to be assigned to the slide housing or slide: pneumatic, hydraulic, elastic, or magnetic. The damping device's function is to brake the slide at the end of its motion path, without necessarily requiring energy to be supplied to the actuator. The slide's motion path does not necessarily correspond to the actuator's maximum stroke but can also be determined by the external conditions of the machine or device in which the actuator is used to provide motion. In pneumatically operated actuators, the pneumatic damper can be integrated into the actuator housing and, in this case, is referred to as an end position damping device. The same applies to hydraulically operated actuators. However, the actuator can also be equipped with a separately designed pneumatic or hydraulic damper, for example, mounted on and protruding from the actuator housing, so that the slide strikes the damping device at the end of a predetermined motion path and is thereby braked along a predetermined braking path. In the case of pneumatic or hydraulic shock absorbers, the damping effect is caused by a fluid flow between a throttle working chamber and the surroundings (pneumatic shock absorbers only) or between two working chambers (pneumatic and hydraulic shock absorbers) connected to each other by a throttle channel. In the case of elastic shock absorbers, it is provided that when the slider strikes the damping device, the damping material elastically deforms, wherein during this elastic deformation, as large a portion as possible of the slider's kinetic energy is converted into heat, so that the damping device exerts minimal or only minimal rebound on the slider. For example, in the case of magnetic shock absorbers, it can be provided that the impact of the slider causes the permanent magnet arrangement in the coil arrangement to move, and the resulting generator voltage is converted into heat via a resistor.

[0024] For each of these damping devices, individual parameters can be provided to the controller via an electrical interface so that a computer program module running in the controller can calculate a damper load value for the damping device from the determined velocity and / or the determined acceleration. This damper load value can be output from the controller to a higher-level control device via the electrical interface so that, for example, a user can be provided with information on a display device associated with the higher-level controller indicating that the damping device may be overloaded or that the damping device is at the end of its life cycle and should be replaced.

[0025] According to a third aspect of the invention, the object of the present invention is achieved by a method for monitoring a motion system, the method comprising the following steps: a controller of the distance sensor supplies a coil current to a magnetic coil arrangement of the distance sensor, the controller determines the inductance of the magnetic coil arrangement, and calculates the distance between the distance sensor and a slide of an actuator that is relatively movably mounted on an actuator housing, and determines a time change in the inductance of the magnetic coil arrangement for calculating a speed and / or acceleration of the slide.

[0026] In a refinement of the method, it is provided that the calculated speed is compared with a rated speed interval and, if the speed is outside the rated speed interval, the controller provides a fault signal, and / or the calculated acceleration is compared with a rated acceleration interval and, if the speed is outside the rated speed interval, the controller provides a fault signal, or, if the speed is within the rated speed interval, the controller is designed to provide a functional signal, and / or if the acceleration is within the rated acceleration interval, the controller is designed to provide a functional signal.

[0027] In another embodiment of the method, the calculated speed and / or the calculated acceleration and / or the fault signal and / or the function signal are provided at an electrical interface, which is designed for, in particular, digital communication with a communication participant electrically coupled to the interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] An advantageous embodiment of the invention is shown in the accompanying drawings. In this case:

[0029] Figure 1 Shows the motion system with actuators, valve terminal, higher-level controller, damping and distance sensors, and

[0030] Figure 2 Show the basis Figure 1 Only a schematic diagram of the braking process of the slider (speed over time). DETAILED DESCRIPTION

[0031] Figure 1 The motion system 1 shown in the figure only schematically and purely exemplarily for motion systems of various configurations comprises an actuator 2 designed as a pneumatic cylinder, a valve island 3 fluidically connected to the actuator 2 , a superordinate controller 4 provided for actuating the valve island 3 , a damping device 5 and a distance sensor 21 .

[0032] Actuator 2 Figure 1 The task not shown in FIG is to provide a linear movement of the slide 7 designed as a piston rod relative to the actuator housing 6 along the movement path 16. For this purpose, for example, in the first functional position (in Figure 1 ) and the second functional position (shown in solid lines in Figure 1 A slide 8, which is arranged at the end on the slide 7, is moved between the two parts (shown by dashed lines in FIG). With such a movement, the slide 8 can, for example, retain goods (not shown) conveyed on a conveyor belt (not shown) on the conveyor belt or transfer them to a discharge chute (not shown) by a lifting movement along the movement path 16.

[0033] Exemplarily, for this purpose, the actuator 2 is designed as a double-acting pneumatic cylinder, which can be moved between a first functional position and a second functional position by optionally venting and exhausting the first supply port 9 and optionally venting and exhausting the second supply port 10 .

[0034] To ensure the desired ventilation and exhaust for the two supply ports 9, 10, a valve module 11 is assigned to the valve terminal 3, on which a first working outlet 12 and a second working outlet 13 are formed. Each of the working outlets 12, 13 is assigned a valve device (not shown) arranged in the valve module 11, by means of which compressed air can be selectively supplied to the corresponding supply port 9 or 10 or the corresponding supply port 9 or 10 can be exhausted.

[0035] The valve island 3 also has an I / O module 14, which can be used to process, for example, the electrical signals of the distance sensors 21. Both the valve modules 11 and the I / O modules 14 are connected, in a manner not shown in greater detail, to an island controller 15 in the valve island 3. The island controller 15 includes, for example, a microprocessor on which a computer program runs in order to process the sensor signals provided by the I / O modules 14 and to provide control signals for the valve modules 11. It is preferably provided that the island controller 15 is designed to control the actuators 2 in a closed-loop manner and, in this case, accesses the sensor signals of the distance sensors 21, which will be described in greater detail below.

[0036] In an embodiment of the valve island (not shown), a plurality of valve modules and / or a plurality of I / O modules and, if appropriate, further functional modules are provided in order to be able to control and / or regulate further functions via the valve island.

[0037] Purely by way of example, the valve island 3 is electrically connected to a higher-level controller 4 , wherein the higher-level controller 4 can be designed, for example, as a machine controller or system controller and, in addition to the valve island 3 , can also control other machine or system components (not shown). Preferably, communication between the higher-level controller 4 and the valve island 3 occurs via a digital bus system, in particular a fieldbus system. By way of example, the higher-level controller 4 is designed to provide motion commands to the valve island 3 , and the valve island 3 converts these motion commands into control commands for the valves accommodated in the valve modules 11 , thereby causing the desired movement of the slide 7 .

[0038] The actuator 2 is arranged on a purely schematically illustrated frame 17 together with the damping device 5 and the distance sensor 21, so that these components are in a spatially fixed arrangement relative to one another. In order for the damping device 5 to achieve the desired damping effect when transferring the slide 7 from the first functional position to the second functional position, the damping device 5 is arranged, for example, opposite the slide 8. In an embodiment not shown, the damping device is integrated into the actuator, as is often the case with pneumatic cylinders with pneumatic end position damping.

[0039] Purely by way of example, the damping device 5 comprises a damper housing 51 fixed to the machine frame 17 and a damper rod 52 accommodated in the housing 51 in a linearly movable manner along a movement axis 53. The damper housing 51 and the damper rod 52 are coordinated with each other so that when the damper rod 52 moves from the position according to Figure 1 When the functional position of the slider 7 is moved relative to the functional position not shown, energy conversion is performed, and the movement of the slider 7 from the first functional position to the second functional position can be braked in a controlled manner by means of the energy conversion. For this purpose, the damping device 5 can be designed as a gas damper, a liquid damper, an elastic damper or a magnetic damper. For example, it is provided that when the slider 7 moves from the first functional position to the second functional position according to the embodiment of the present invention, the damping device 5 can be designed as a gas damper, a liquid damper, an elastic damper or a magnetic damper. Figure 1 In the event of a deflection from the functional position, the damping device 5 brakes the slide 7 along a first path section 54 using a first damping method from the group consisting of liquid damping, gas damping, and magnetic damping. Along this first path section 54, the slide 7's kinetic energy is completely converted into heat energy. Elastic motion damping occurs along a second path section 55, for example, by a rubber-elastic damping element housed in the damper housing 51, against which the damper rod 52 strikes after traversing the first path section 54. During this elastic damping, the majority of the remaining kinetic energy of the slide 7 is converted into heat. However, a certain portion of the kinetic energy is temporarily stored in the rubber-elastic damping element (not shown), generating a restoring force on the slide 7, thereby causing it to move back toward the first functional position over at least a portion of the second path section 55 before it comes to a complete stop. The sum of the first path section 54 and the second path section 55 constitutes the damping path 56, the section of the damper rod 52 that is displaced the most when used with the actuator 2. Wear and aging cause changes in the damping characteristics of the damping device 5 , which manifest themselves, for example, in a changed velocity and / or acceleration profile for the damping rod 52 and can be detected and evaluated by means of the distance sensor 21 .

[0040] Purely by way of example, the distance sensor 21 is arranged adjacent to the damping device 5 and serves to detect the slide 7 and in particular the slide plate 8, which is preferably made of a metallic material, in particular a soft-magnetic material, in order to ensure a favorable interaction with the distance sensor 21. When the distance sensor 21 is arranged relative to the slide plate 8, axial alignment is also mentioned.

[0041] In an embodiment of the movement system (not shown), the distance sensor is aligned transversely to the movement path and can detect the passage of the sliding plate. This arrangement of the distance sensor is also referred to as a radial arrangement.

[0042] The distance sensor 21 is shown only schematically and comprises a sensor housing 22, in which a magnetic coil arrangement 23, a controller 24, and an electrical interface 25 are arranged. The magnetic coil arrangement 23 may comprise one or more magnetic coils, in particular cylindrical coils arranged coaxially with one another. The magnetic coil arrangement 23 is electrically connected to the controller 24, which is designed as an electronic circuit and, purely by way of example, comprises a microprocessor (not shown) as well as peripheral components such as an electrical output stage, amplifiers, and other electrical and electronic components to enable the sensing of the functions described in more detail below. The electrical interface 25 is electrically connected to the controller 24 and is used for communication with the I / O module 14. For example, it is provided that the I / O module 14 is designed as an IO-Link master and the electrical interface 25 is designed as an IO-Link device, also referred to as an IO-Link device. Furthermore, purely by way of example, it is provided that a bidirectional communication connection exists between the I / O module 14 and the electrical interface 25, so that the distance sensor 21 can provide information, in particular a speed signal and / or an acceleration signal, to the I / O module 14, which can, for its part, provide parameters for processing the sensor signal to the distance sensor 21, for example.

[0043] In accordance with Figure 1 In the illustrated distance sensor 21 , the controller 24 and the electrical interface 25 are each designed as a separate component. Alternatively, in an embodiment of the distance sensor not shown, the controller and the electrical interface are designed as a common component, in particular as a common microcontroller.

[0044] The function of distance sensor 21 can be described as follows: Distance sensor 21 is supplied with electrical energy via I / O module 14, allowing controller 24 to supply high-frequency alternating current to magnetic coil arrangement 23 via an output stage (not shown). This outputs an alternating magnetic field from magnetic coil arrangement 23 into the environment of distance sensor 21. As soon as slide 8 is moved from a first functional position to a functional position shown only in dashed lines, it enters detection range 26 of distance sensor 21, symbolically represented by three coaxially arranged circular segments. In this detection range 26, the magnetic interaction between the alternating magnetic field provided by distance sensor 21 and slide 8, which is preferably made of a soft-magnetic metallic material, induces an inductive change in magnetic coil arrangement 23 that can be detected and evaluated by controller 24. A change in the inductive change of magnetic coil arrangement 23 has already occurred before slide 8 enters detection range 26, but this change is too weak to allow reliable position determination by distance sensor 21.

[0045] In a first evaluation step, controller 24 determines the position of slide 8 relative to distance sensor 21 from the inductive change. In a subsequent evaluation step, controller 24 evaluates the change in position value within a given time interval using a cyclic evaluation method. This corresponds to a time derivative of the position value and results in a velocity value. From this velocity value, controller 24 can calculate an acceleration value in a further time derivative step. It is preferably provided that the evaluation of the distance value and the evaluation of the velocity value determined from the distance value by time derivative are performed at a repetition rate greater than 1 kHz, preferably greater than 5 kHz, and in particular greater than 8 kHz. It is particularly preferably provided that the controller operates for this purpose with a clock frequency that is selected to be greater than the repetition rate, for example, 10 times the repetition rate.

[0046] By way of example, the controller is designed to provide speed and / or acceleration values ​​at a predetermined output frequency, which is selected as a low output frequency, in particular, significantly lower than the repetition frequency, to an electrical interface 25, which can forward the speed and / or acceleration values ​​to the I / O module 14. IO-Link specifies three transmission speeds, COM1, COM2, and COM3, ranging from 4.8 kbit / s through 38.4 kbit / s to 230.4 kbit / s, wherein the transmission speed can be selected by the I / O module 14 by parameterizing the electrical interface 25.

[0047] Figure 2 Purely schematically, the slide 7 and the slide 8 arranged thereon are shown as follows Figure 1 The velocity curve resulting from the interaction with the damping device 5 when the actuator 2 moves from its first functional position to its second functional position. In this case, it is assumed that, starting from the first functional position until the second functional position is reached, constant ventilation occurs at the first supply port 9 of the actuator 2 and constant exhaust occurs at the second supply port of the actuator 2. Alternatively, different operating modes can be provided for ventilating and exhausting the actuator 2.

[0048] In accordance with Figure 2 In the speed curve diagram, only the movement stage of the slider 7 is shown, wherein the slide plate 8 continuously approaches the damping rod 52 of the damping device 5 until the damping rod 52 moves from the damping rod 52 according to the Figure 1 The first functional position is pivoted into a second functional position (not shown).

[0049] Purely by way of example, it is assumed that the slide 7 is transferred from the first functional position to the second functional position along the motion path at a constant speed until time t1. At time t1, the slide 8 strikes the damping rod 52, thereby displacing the damping rod 52 relative to the damper housing 51 and completely converting the slide 7's kinetic energy into heat energy within the damping device 5. For example, a damping fluid (oil, compressed air) is conducted from the first working chamber via a throttle valve by a working piston (not shown) coupled to the damping rod 52 into the second working chamber. Consequently, the slide 7's velocity decreases. This velocity decrease initially occurs with a high negative acceleration immediately after the slide 8 strikes the stop 52, as the inertia of the damping rod 52 must be overcome. From time t2 onward, the speed of the slide 7 is essentially determined by the damping function of the damping device. Thus, purely by way of example, a certain velocity increase occurs between time t2 and time t5. Subsequently, until time t6, the speed of the slide 7 decreases again slightly, due to the increased damping effect. At time t6, the stop 52 encounters a rubber-elastic damping element (not shown) arranged in the housing 51, thereby rapidly braking until time t7. Between time t7 and time t8, the slide 7 rebounds slightly until a force balance is achieved between the pressure exerted by the actuator 2 on the slide 7 and the reaction force acting due to the elastic deformation of the rubber-elastic damping element, and the slide 7 has thus reached the second functional position.

[0050] Based on the distance sensor 21, it can be assumed that the slide 8 enters the detection area 26 at time t3, so that from this time onwards, the position, velocity, and acceleration can be determined. For the sake of clarity, reference is made below to times t4, t5, and t6 purely by way of example, which would preclude a complete description of the braking process by the damping device 5. In practice, the braking process typically takes place within a time interval between 15 milliseconds and 30 milliseconds, resulting in a total of 15 to 30 position measurements at a repetition rate of 1 kHz, which can be used to describe the braking process. At a repetition rate of 5 kHz, 75 to 150 position measurements are taken, and at a repetition rate of 8 kHz, 120 to 240 position measurements are taken, which can be used to describe the braking process.

[0051] Under the simplified premise that the controller 24 of the distance sensor 21 only performs position measurements at times t4, t5, and t6, a first position difference can be determined at time t5 compared to time t4, thereby determining the first average velocity of the slider 7 during that time interval. Furthermore, at time t6, a second position difference can be determined compared to time t5, thereby determining the second average velocity of the slider during that time interval. Furthermore, based on the difference between the first and second average velocities, the velocity change for the time period between time t4 and time t6 can be determined, thereby determining the acceleration of the slider 7 during that time period. Preferably, the time interval between t4 and t5 is equal to the time interval between t5 and t6.

[0052] Provision is preferably made for controller 24 to forward the determined average speed and / or the determined acceleration to electrical interface 25 at time intervals adapted to the communication settings of electrical interface 25 , so that electrical interface 25 can provide the determined speed and / or acceleration to I / O module 14 .

[0053] Additionally or alternatively, it can be provided that the controller 24 compares the currently determined speed and / or the currently determined acceleration with a stored rated speed interval and / or a rated acceleration interval and optionally provides a fault signal to the electrical interface 25 if the speed is outside the rated speed interval and / or if the acceleration is outside the rated acceleration interval, or provides a functional signal to the electrical interface 25 if the speed is within the rated speed interval and / or the acceleration is within the rated acceleration interval.

[0054] Additionally, the controller 24 can be designed to evaluate a velocity curve and / or an acceleration curve and / or a maximum velocity and / or a maximum acceleration in order to calculate therefrom an actuator load value and / or a shock absorber load value, which are also provided to the I / O module 14 at a predetermined repetition rate or output at regular or irregular time intervals via a query signal of the I / O module 14.

Claims

1. A distance sensor (21) for detecting the relative movement of a slider (7) relative to a slider housing (6), comprising a magnetic coil arrangement (23) and a controller (24) electrically connected to the magnetic coil arrangement (23), wherein the controller (24) is designed to supply a coil current to the magnetic coil arrangement (23), to determine the inductance of the magnetic coil arrangement (23), and to process the determined inductance into a distance value, and to periodically evaluate the distance value to determine the speed of the slider (7) and / or the acceleration of the slider (7), and having an electrical interface (25) connected to the controller (24) and designed for unidirectional communication with a communication participant (4) according to a predetermined, in particular digital, communication protocol, or the electrical interface (25) is designed for bidirectional communication with a communication participant (4) according to a predetermined, in particular digital, communication protocol.

2. The distance sensor (21) according to claim 1, characterized in that The controller (24) is designed to cyclically evaluate the distance values ​​to determine the speed and / or acceleration with a repetition frequency of greater than 1 kHz, preferably greater than 5 kHz, in particular greater than 8 kHz.

3. The distance sensor (21) according to claim 1 or 2, characterized in that The electrical interface (25) is designed for signal output according to the IO-Link standard or for signal output and signal reception according to the IO-Link standard.

4. The distance sensor (21) according to claim 1, 2 or 3, characterized in that The controller (24) is designed to provide an electrical interface (25) with a velocity, in particular a position-dependent velocity, and / or an acceleration, in particular a position-dependent acceleration.

5. The distance sensor (21) according to any one of claims 1 to 4, characterized in that The controller (24) is designed to provide a fault signal when the speed is outside the rated speed range and / or when the acceleration is outside the rated acceleration range, or is designed to provide a function signal when the speed is within the rated speed range and / or when the acceleration is within the rated acceleration range.

6. The distance sensor (21) according to one of the preceding claims, characterized in that The controller (24) is designed to evaluate a velocity profile and / or an acceleration profile in order to determine a component load value, in particular an actuator load value or a shock absorber load value.

7. A motion system (1) for providing motion, comprising an actuator (2) from the following group: pneumatic cylinder, hydraulic cylinder, electric linear direct drive, electric threaded spindle drive, electric toothed belt drive, the actuator comprising an actuator housing (6) and a slide (7) mounted on the actuator housing (6) so as to be movable relative to the actuator housing, and a distance sensor (21) designed according to one of claims 1 to 6.

8. The motion system (1) according to claim 7, characterized in that The slide housing (6) or the slide (7) is assigned a damping device (5) from the following group: pneumatic damper, hydraulic damper, elastic damper, magnetic damper.

9. A method for monitoring a motion system (1), comprising the following steps: a controller (24) of a distance sensor (21) supplies a coil current to a magnetic coil device (23) of the distance sensor (21); the controller (24) determines the inductance of the magnetic coil device (23); and calculates the distance between the distance sensor (21) and a slider (7) of an actuator (2) that is relatively movably mounted on an actuator housing (6); and determines a temporal change in the inductance of the magnetic coil device (23) for calculating the speed and / or acceleration of the slider (7).

10. The method according to claim 9, characterized in that The calculated speed is compared with a rated speed interval, and if the speed is outside the rated speed interval, the controller (24) provides a fault signal, and / or the calculated acceleration is compared with a rated acceleration interval, and if the speed is outside the rated speed interval, the controller (24) provides a fault signal, or if the speed is within the rated speed interval, the controller is designed to provide a functional signal, and / or if the acceleration is within the rated acceleration interval, the controller is designed to provide a functional signal.

11. The method according to claim 10, characterized in that The calculated speed and / or the calculated acceleration and / or the fault signal and / or the function signal are provided at an electrical interface (25), which is designed for preferably unidirectional, particularly preferably bidirectional, in particular digital communication with a communication participant (4) which is electrically coupled to the electrical interface (25).

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