Decoupled measuring system for vertical position changes

Abstract

The invention relates to a system for determining position information of a measurement position of a measurement object. The system comprises a sensor strip, a sensor, a traction cable, and at least one deflection pulley. The position information is determined by the sensor detecting position information on the sensor strip. The traction cable, deflected by the deflection pulley from a first direction to a second direction, transmits the measurement position of the measurement object to the sensor. The invention enables the measurement of a measurement position of a measurement object using a measuring system spaced apart from the measurement object.

Description

[0001] The invention relates to a measuring system for determining position information of a measurement position of a measurement object, a table with such a measuring system and a medical device with such a table and / or such a measuring system.

[0002] When moving machine axes, for example, in medical devices, it is advantageous to be able to precisely record or measure the respective axes' travels or corresponding target positions. Linear measuring systems are typically used for such measuring tasks. These systems are located directly on / at the axis to be measured and allow direct and continuous measurement of the position of the measuring object. Linear measuring systems are particularly characterized by their high measurement accuracy and robustness. Alternatively, wire feeders can be used if the use of linear measuring systems is not possible. Indirect measurements of the drive kinematics can also be used, with subsequent calculation of the resulting drive position / movement.

[0003] JP 2000 - 337 804 A describes a displacement measuring device for measuring an interlayer displacement of an upper floor via a wire and a structural component of a lower floor.

[0004] DE 20 2013 105 220 U1 describes an arrangement for holding an object, in particular a tool holder for holding a tool, in particular a measuring probe or a machining tool.

[0005] However, these alternative measurement methods have various disadvantages. With an indirect measurement, no discrete measurement is performed, so geometric errors in the kinematics can influence the result. Wire-actuated encoders have measurement inaccuracies, primarily due to the cable drum principle, i.e., the winding and unwinding of a rope or thread on a spool over several revolutions or even several layers with a corresponding number of revolutions. Furthermore, the inaccuracies in position measurement with wire-actuated encoders are not constant across the entire measuring range. Even correction values, such as gradient compensation, cannot ensure sufficiently good accuracy for specific requirements, such as position detection in radiotherapy applications. As the measuring length of the wire-actuated encoder increases, the measurement inaccuracy increases consecutively.Wire-actuated encoders are therefore not suitable for certain applications or are significantly less suitable than linear measuring systems.

[0006] For some applications where precise position measurement is required, linear measuring systems cannot be installed on or at the axes or measurement positions to be measured. For example, in scissor lift modules, especially in radiotherapy systems where high precision is required, the vertical position / travel cannot be measured using a linear measuring system.

[0007] The object of the invention can be considered to enable a reliable, exact measurement of measuring positions, in particular in the height direction (y-direction), for devices in which known measuring systems, in particular linear measuring systems, cannot be used due to the geometric nature of the device.

[0008] A measuring system for determining position information of a measurement position of a measurement object is proposed. The measuring system comprises a sensor tape and a sensor that detects position information on the sensor tape. Furthermore, the measuring system comprises a traction cable for transmitting a measurement position of the measurement object to the sensor, and a deflection pulley that deflects the traction cable from a first direction to a second direction.

[0009] The position information can preferably describe the (ideally actual) spatial position of the measurement position of the measurement object. The position information can preferably comprise a three-dimensional and / or two-dimensional description (in x and y) of the measurement point starting from a reference object, in particular a reference point, by means of a coordinate system. The reference point (e.g. zero point of the coordinate system) is preferably arranged on or at the measuring system, in particular the sensor strip. In particular, the reference point can be the starting point of the sensor and / or the point at which the sensor is arranged on the sensor strip in the starting position of the measurement object. Alternatively, the reference point (e.g. zero point of the coordinate system) can preferably be arranged on or at the measurement object. The measurement position can preferably be the position on the measurement object at which the traction cable is connected to the measurement object.Alternatively, the measuring point can in particular also be another point located on and / or in the measuring object, for example the geometric center of the measuring object or a center point of a surface of the measuring object. In this case, the location / position of the referenced point on / in the measuring object is preferably known. The position information can in particular be a distance and / or path. In particular, the position information can be an altitude specification and / or a length value of a path in the y-direction of a coordinate system. In particular, the position information can be read as a length value directly on the measuring system and / or determined by the sensor on the positioning tape and transferred / output to a system and / or user interface.

[0010] The measurement object is, in particular, the object on which the measurement point is arranged. The measurement object can preferably comprise the measuring system. Alternatively, the measuring system can be part of another object / device or arranged outside the measurement object. The measurement object can, in particular, be a medical device. For example, the measurement object can be a medical imaging device, a medical therapy device, and / or a part / component of a medical device. For example, the measurement object can be a patient bed.

[0011] The sensor strip can, in particular, be a scale and / or a measuring tape. The sensor strip can, in particular, be designed as a strip and / or a rod, preferably made of metal, ceramic, glass, or glass ceramic. Alternatively, the sensor strip can also have a different geometric shape on which a sensor can be arranged for a measurement. The sensor strip can, in particular, have a smooth surface. The sensor strip can preferably comprise a groove, recess, strip, or guide with which the sensor can preferably be positioned and / or guided on the sensor strip. The sensor strip can preferably have a coding, scale, or measurement. For example, a special code pattern on the sensor strip can enable precise position determination of the sensor without knowledge of the previous position. Calibration or zeroing is advantageously not necessary in this case.Preferably, in sensors with an incremental output signal, the sensor can comprise a calibration mark, reference position, reference magnet, and / or index pulse that enables calibration and / or the determination of the absolute position. For example, the sensor band can comprise a magnetic strip. The magnetic strip can preferably comprise alternating magnetic north and / or south poles at specified intervals.

[0012] The sensor can also be referred to as a sensor head, read head, scanner, and / or displacement sensor. The sensor can preferably be a displacement sensor. The sensor can preferably be a magnetic, inductive, magnetostrictive, or scanning sensor. For example, the sensor can comprise a magnetoresistive sensor or Hall sensor. The sensor can preferably convert a linear movement into analog or digital signals, in particular position information. The sensor can in particular be arranged on the sensor strip and / or surround it. Preferably, the sensor is movable on the sensor strip only along a line in two directions. In other words, the sensor has only one degree of freedom of movement, for example in the x-direction in a coordinate system arranged at the origin of a linear sensor strip.In particular, the sensor can be an absolute measuring sensor that outputs an absolute position along a measuring path, in particular the sensor strip, as an output signal. Alternatively, the sensor can return an incremental output signal. In this case, a determination of the absolute position via zeroing and / or calibration is preferably necessary. The sensor can preferably be arranged in a movable housing. The sensor, together with the sensor strip, can be referred to as a length measuring system, linear measuring device, and / or strip sensor. The sensor can preferably be guided and / or measured without contact over / on the sensor strip, so that the measurement can be carried out frictionlessly and without wear.

[0013] The traction cable can, in particular, refer to a cable under tension. The traction cable can preferably comprise metal and / or plastic. In particular, the traction cable can comprise a steel cable, a plastic cable, a carbon fiber cable, and / or a cable made of a material with a high modulus of elasticity, preferably 200 GPa or greater. The traction cable preferably exhibits a small, quantifiable, and continuous linear expansion upon application of a specific tensile force and / or restoring force. The traction cable is preferably temperature-resistant, in particular so that the traction cable exhibits the smallest possible change in length upon temperature changes. The traction cable is arranged, in particular, between the measurement object, in particular the measurement position, and the sensor. In other words, the traction cable represents a mechanical, in particular kinematic, connection between the measurement object, in particular the measurement position, and the sensor.The traction cable is preferably mechanically connected to the measurement object. The traction cable is preferably mechanically connected to the sensor. A change in position or position of the measuring position can preferably cause an identical (or with a defined translation) change in length or position of the sensor on the sensor strip via the traction cable. The mechanical properties of the cable can depend on various environmental conditions and / or parameters, such as radiation intensity, magnetic fields, force applied, for example, by a (return) spring, temperature, and air humidity. The properties of the traction cable, such as radiation resistance, magnetic properties, technical elongation, temperature resistance, and corrosion properties, can preferably be designed according to the environmental conditions and / or parameters present during the determination of position information for a measuring position.

[0014] The deflection pulley can preferably change the direction of the traction cable in a targeted manner. The deflection pulley can preferably deflect the traction cable from a first direction, which runs between the measuring position of the deflection pulley, to a second direction, which runs between the deflection pulley and the sensor. In other words, an alignment angle between the first direction and the second direction can be defined via a deflection pulley. The traction cable can preferably be guided through the deflection pulley. In particular, the deflection pulley can have a groove, recess, or track designed to receive and guide the traction cable.

[0015] The measuring system advantageously enables robust, precise measurements across the entire measuring range, similar to those of a linear measuring system. A particularly advantageous feature is the ability to spatially separate the measuring system from the measuring object. This enables position measurement on measuring objects, which is not possible with conventional measuring systems, such as linear measuring systems.

[0016] In one possible embodiment of the measuring system, the measurement of a position change of the measuring position of the measuring object in the first direction by means of the sensor is carried out by a position change of a position of the sensor on the sensor band in the second direction.

[0017] A change in position or position of the measuring position (in a first direction) can preferably cause an identical (or with a defined reduction / transmission) change in the position of the sensor on the sensor strip (in a second direction) via the pull cable. A vertical change in the position of a measuring object can preferably be determined by a horizontal displacement of the sensor on the sensor strip. The second direction is preferably horizontal or horizontal, but can also have an inclination. The first direction is preferably vertical, but can also have an inclination. The first direction and the second direction are preferably orthogonal to one another. The first direction of the change in position of a measuring position refers in particular to the direction in which a movement or displacement of the measuring position occurs.The second direction of the position change of a sensor refers in particular to the direction in which the sensor moves or shifts. Preferably, the first and second directions can be determined in a coordinate system. The coordinate system can in particular correspond to the coordinate system used to change the position of a measuring position. The coordinate system can in particular be arranged at a point, for example the starting point, of the measuring system, in particular of the sensor strip. The second direction is preferably unchanging and / or constant over a period of time, in particular a measuring period. The second direction is preferably also constant over a period of time, in particular a measuring period, but may also be non-constant. In other words, the first direction (of the measuring position) can vary over a period of time, in particular a measuring period, starting from a constant second direction.

[0018] The measuring system advantageously enables the measurement of a position and / or distance in a first (variable) direction by means of a measurement in a second (defined) direction. This allows flexibility in the arrangement and measurement method of the measuring system, since the measurement is always performed in a defined measuring direction. Furthermore, a space-saving and compact design is possible, thus reducing the design effort of the device.

[0019] In one possible embodiment of the measuring system, the first direction is vertical and the second direction is horizontal.

[0020] Preferably, the movement of the measuring position occurs along a vertical or perpendicular axis and / or direction. Preferably, the movement of the sensor on the sensor strip is horizontal and / or parallel to the ground. The first direction and second direction are therefore preferably arranged orthogonally to each other. In other words, the angle between the directional axes of the first and second directions is 90°. The traction cable preferably also runs vertically in the first direction and horizontally in the second direction.

[0021] The measuring system advantageously enables the measurement of a vertical position change based on a horizontal measurement. Depending on the measurement method, a horizontal measurement may be more advantageous than a vertical measurement, since, for example, a vertical measurement may be influenced by the Earth's gravitational force. For example, a horizontal measurement of vertical position changes by the measuring system can enable a large vertical measurement range.

[0022] Alternatively, in one possible embodiment, the first direction can be horizontal and the second direction vertical. For example, the movement of the sensor on the sensor strip can be parallel to a vertically arranged wall (on a horizontal floor). This can advantageously also enable a vertical measurement of a horizontal position change. For example, the force of gravity can advantageously be used as a restoring force for the sensor. In particular, the measuring system can enable the measurement of a large horizontal measuring range.

[0023] In one possible embodiment of the measuring system, the traction cable is mechanically connected to the measuring object and / or the sensor.

[0024] The mechanical connection, preferably between the measurement object and the sensor by the pull cable, leads in particular to a corresponding displacement of the sensor on the sensor strip when the measurement position changes. In other words, a movement of the measurement object can be measured by the measuring system, in particular the sensor. Alternatively, the pull cable can in particular form a mechanical connection between a deflection pulley arranged on the sensor and the measurement position. The connection or fastening to the respective components, in particular the sensor and the measurement object, is preferably designed such that the pull cable can be replaced, but at the same time a high level of safety is ensured. The pull cable in particular represents a direct connection between the measurement position and the position of the sensor. The pull cable is preferably constantly under tensile stress.This ensures error-free redirection of the pull cable and provides direct transmission of the measurement position to the sensor. Instead of a cable, spindles or other connecting elements can also be used.

[0025] Advantageously, a mechanical connection between the measuring object and the sensor via the pull cable enables direct transmission of the position and / or position change of the measuring position to the sensor. This enables an exact measurement of the measuring position at a point on the sensor tape (sensor measuring point) that is distant from the measuring position.

[0026] In one possible embodiment of the measuring system, the measuring system comprises a guide. The guide of the measuring system guides the sensor along the sensor tape.

[0027] The guide is preferably designed to allow movement of the sensor only in one direction, for example, only in the x-direction in a coordinate system arranged at a starting point. In particular, a lateral and / or sideways movement and / or rotation and / or tilting of the sensor can be limited by the guide. The guide can preferably comprise a rail and a carriage accommodating the sensor. Alternatively, the guide can in particular be a component of the sensor strip. The guide can in particular be arranged in / on a housing, which can in particular comprise the sensor and / or the sensor strip.

[0028] The guide can advantageously ensure an exact positioning of the sensor on the sensor tape and therefore reduce measurement inaccuracies and / or enable an accurate measurement of the measuring position.

[0029] In one possible embodiment of the measuring system, the measuring system comprises a return spring. The return spring is preferably mechanically connected to the sensor and / or pull cable.

[0030] The return spring preferably enables precise positioning of the sensor on the sensor band. The return spring can preferably be arranged between the sensor and a non-movable fastening point of the measuring system. The non-movable fastening point can in particular be arranged at one end of the sensor band. The non-movable fastening point can preferably be arranged on a housing surrounding the measuring system. The return spring can also be arranged in particular between the pull cable and a non-movable fastening point. The return spring can simultaneously exert a tensile force on the pull cable and / or the sensor. Alternatively, the return spring can also exert a compressive force on the sensor and / or the pull cable. In particular, a tensile or compressive force generated by the return spring can be constant.Furthermore, the return spring can be designed to transmit a force, in particular a linear one, to the sensor and / or the pull cable. For example, the compressive force of the return spring can be maximum in an initial state and minimum in a maximum measurement state.

[0031] The measuring system can also comprise more than one (return) spring. For example, the measuring system can have a spring between the sensor and the non-movable attachment point and another spring between the traction cable and the non-movable attachment point and / or sensor. For example, two or more springs can be arranged in series, in particular to transmit a specific spring force and / or restoring force to the traction cable. Furthermore, differently deactivated springs and / or spring types can be combined and / or arranged together to form a spring system, in particular a return spring system. In particular, a defined spring characteristic curve can be determined using such a spring system, in particular a return spring system. For example, the arrangement of a kinematic deflection element on the spring is also conceivable, in particular to exert a constant tensile force, in particular a restoring force, on the traction cable.The return spring can advantageously comprise, for example, a gas spring. A gas spring can preferably provide a constant return force. Furthermore, the return spring can comprise a spring system, in particular a return spring system. A spring system, in particular a return spring system, can in particular comprise a spring tensioner. A spring tensioner can in particular comprise a torsion spring in conjunction with a constantly variable cable radius of a take-up spool, in particular in order to provide a constant return force and / or tensile force. Instead of a return spring, another object with a comparable function can also be used. For example, a foam or an object made of compressible material can be used.

[0032] A return spring can advantageously enable guidance and / or positioning of the sensor on / at the sensor tape and increase the measuring accuracy of the measuring system.

[0033] In one possible embodiment of the measuring system, the measuring system comprises a return spring. The tension spring can apply a return force to the pull cable and / or the sensor.

[0034] Preferably, the sensor and the traction cable are acted upon by means of a return spring. Applying a restoring force to the sensor can, in particular, ensure the sensor's return to a measurement starting point upon a corresponding change in the measurement position of the measurement object. Applying a restoring force to the traction cable can, in particular, ensure a constant tensile stress state of the traction cable. This can, in particular, enable error-free guidance and / or deflection of the traction cable by the deflection pulleys. In other words, the constant tension applied to the traction cable ensures that it is in a state in which it cannot become knotted, caught, or sag.

[0035] Applying a restoring force to the sensor and / or the traction cable can advantageously ensure the direct transfer of the measuring position of the measuring object to the sensor measuring position on the sensor tape.

[0036] The measuring system includes at least one additional pulley. The pulley redirects the traction cable.

[0037] A further deflection pulley can in particular enable precise alignment and / or guidance of the traction cable. Preferably, the at least one further deflection pulley is arranged at a distance from a first deflection pulley. Due to the geometric properties of the measurement object, for example, several deflections of the traction cable may be necessary to transmit the measurement position of the measurement object to the sensor strip. For example, the traction cable can be guided around an obstacle (object) located between the first deflection pulley and the measurement position. In addition, a reduction / transmission of the traction cable can be made possible in particular by a further deflection pulley. However, the measuring system is preferably constructed with as few deflection pulleys as possible. A deflection pulley can also be used to stabilize or guide the traction cable and can therefore be referred to differently, for example as a roller or guide roller.

[0038] Advantageously, additional pulleys can improve the alignment or guidance of the traction cable. This can, in particular, lead to improved transmission of the (vertical) measurement position to the sensor tape of the measuring system.

[0039] In one possible embodiment of the measuring system, the measuring system comprises at least one further deflection pulley which is mechanically, in particular rigidly, connected to the sensor.

[0040] In order to enable a reduction / transmission ratio, the deflection pulley can be arranged on the sensor. The mechanical connection between the sensor and the deflection pulley can in particular be rigid. Alternatively, the mechanical connection can also be made via an elastic element, for example. The sensor is preferably attached to a frame and / or housing element of the sensor. In other words, the deflection pulley can also be attached to the sensor. Attaching the deflection pulley to the sensor enables a deflection of the pulley at the sensor. Deflecting the pulley at the sensor enables a reduction / transmission of the measuring system similar to a pulley system in terms of functionality. In particular, one or more additional deflection pulleys can be attached to the sensor.

[0041] Advantageously, a deflection of the pull rope at the sensor enables a particularly compact design of the measuring system.

[0042] In one possible embodiment of the measuring system, the measuring system comprises a non-movable attachment point to which the traction cable is attached.

[0043] The immovable attachment point can be arranged, in particular, at one end of the sensor band. The immovable attachment point can preferably be arranged on a housing surrounding the measuring system. For example, the attachment point can also be arranged on a deflection pulley. In particular, the attachment of the pull cable to a immovable attachment point of the measuring system can enable a reduction of the pull cable. The attachment point is, in particular, immovable with respect to the sensor band or a housing (surrounding the measuring system). The attachment of the pull cable can be effected, in particular, by means of a (cable) clamp, hooks, eyelets, split pins, or screws. In particular, the attachment can be effected in such a way that the replacement, adjustment, or retensioning of the pull cable is possible.

[0044] Advantageously, attaching the pull cable to a fixed attachment point simplifies the attachment of the pull cable, especially since the pull cable is not attached to the sensor. This can advantageously lead to improved guidance and / or positioning of the sensor on the sensor strip.

[0045] In one possible embodiment of the measuring system, the measuring distance on the sensor tape determined by the sensor corresponds to an integer multiple of the position distance of the measuring position.

[0046] The deflection pulleys of the measuring system can preferably act like a pulley system with / through an appropriate factor, depending on the arrangement of the deflection pulleys. In other words, a step-up / step-down ratio can be enabled by the arrangement of the deflection pulleys in the measuring system. In particular, a measuring distance and / or the necessary restoring force can be reduced by a step-down / step-down ratio. In particular, the factor can be an integer, for example 1, 2 or 5. An appropriately selected factor enables, in particular, a compact design of the measuring system and / or a short sensor band. In particular, a step-down of the measuring distance of the measuring position into a measuring distance of the sensor on the sensor band can be applied with a factor for large or long (vertical) measuring distances.

[0047] A reduction gear advantageously enables scaling of the measuring system. Large vertical measuring distances, in particular, can be measured with a short sensor tape and / or a compact measuring system.

[0048] In one possible embodiment of the measuring system, the measuring system comprises a housing.

[0049] In particular, the housing can encompass the sensor and the sensor band. Preferably, one or more deflection pulleys can also be encompassed by the housing. Preferably, one or more (return) springs can also be encompassed by the housing. In other words, the measuring system can be enclosed by a protective component. Preferably, the housing has an opening through which the traction cable can enter and / or exit the housing. In particular, the opening in the housing can have a guide and / or seal. In particular, the seal can be designed to prevent and / or reduce the penetration of dirt and / or dust particles into the housing.

[0050] In particular, the housing can advantageously prevent and / or reduce contamination of the sensor and / or the sensor strip. Mechanical components, such as a guide that holds the sensor, can thus be protected from wear. Closed measuring systems and / or enclosed measuring systems can be less sensitive to external influences, such as dust particles, and enable more reliable measurements due to a reduced probability of failure.

[0051] One possible embodiment of the invention comprises a table comprising a lifting device, further comprising the measuring system (in one of the possible embodiments). The height of the table can be adjusted by means of the lifting device. The height of the table can be determined by means of the measuring system. The lifting device of the table can, in particular, comprise a scissor-type lifting device.

[0052] For example, the table can be a patient couch or a patient table. In particular, the table can be designed to accommodate a patient. Preferably, the table can be a component of a medical device. In particular, the table can be raised to a precise vertical height. The measuring system enables precise determination of the table height. In the case of a scissor lift table, for example, the attachment of conventional linear measuring systems to the movement axes may not be possible. Furthermore, the measuring system can preferably enable the measurement and / or determination of the lifting speed during a movement of the table.

[0053] The measuring system advantageously enables precise height measurement of the table. The measuring system is advantageously a device that does not need to be mounted directly on the movement axis or lifting axis. The determined and / or measured lifting speed can also advantageously enable the control of a table drive.

[0054] One possible embodiment of the invention comprises a medical device comprising the table and / or the measuring system. The medical device is particularly designed for recording medical image data.

[0055] In particular, the medical device may be a medical imaging system. A medical imaging system may generally be configured to generate medical image data. Medical image data may generally be image data of a patient's body part. Accordingly, medical imaging systems are configured to image patient body parts. In particular, medical imaging systems may implement radiological imaging methods. Medical imaging systems may include one or more imaging modalities, such as computed tomography devices, magnetic resonance imaging devices, X-ray devices, or ultrasound devices, and the like. Alternatively, the medical system may be a therapy device.In particular, the medical system can be an irradiation device by means of which a patient arranged on a (patient) table can be treated with radiation in a locally defined body area.

[0056] Especially for medical devices, especially medical imaging procedures, a spatial separation of the measuring system from the measurement position is particularly advantageous. The radiation (or magnetic fields) required for imaging and / or therapy can influence and / or impair the electronics in the measuring systems. By coupling the measuring position to the sensor of the measuring system with a pull cable, influences on the measuring system, for example, from the magnetic field of a magnetic resonance device, can be largely avoided by maintaining a spatial separation.

[0057] Further advantages, features, and details of the invention will become apparent from the exemplary embodiments described below and from the drawings. Corresponding parts are provided with the same reference numerals in all figures. A repeated description of corresponding parts in the respective exemplary embodiments is omitted. Exemplary embodiments may differ essentially in the arrangement of the units.

[0058] They show: Fig. 1 a measuring system for measuring the position of a measuring object movable in a first direction Fig. 2 a measuring system for measuring the position of a measuring object movable in a first direction with reduction Fig. 3 a (scissor lift) table with a measuring system for height measurement in the initial state Fig. 4 a (scissor lift) table with a measuring system for height measurement in a measuring position

[0059] In Fig. 1 schematically illustrates a measuring system 20 suitable for measuring the position of a measuring object 18 displaceable in a first direction R1. A traction cable 10 attached to a measuring position 17 transmits the position or movement (position change) of the measuring object 18 (or the measuring position 17) to the sensor 13. The sensor 13 moves in a direction R2 on a sensor belt 14 and is connected to the traction cable 10. The deflection pulley 11 is arranged between the measuring position 17 and the sensor 13 and deflects the traction cable 10 from a direction R1 into a direction R2. Positioning the deflection pulley 11 at the end of the sensor belt 14 enables the traction cable 10 to be guided parallel and / or horizontally to the sensor belt 14. A return spring 12 is attached to the sensor 13. In addition, the return spring 12 is attached to one end of the sensor band 22 and / or to a housing 9.The return spring 12 returns the sensor 13 to its initial state when the measurement object 18 moves opposite to the measuring direction R1. In addition, the return spring 12 ensures that the pull cable 13 is always under tension. Contrary to what is shown, a second spring can also be provided, for example, between an initial point 22 and the pull cable 10. The measuring system 20 can be surrounded by a housing 9. In particular, the housing 9, as shown, can comprise the sensor 13, the sensor band 14, a deflection pulley 11 and the return spring 12. Other deflection pulleys can also be encompassed by the housing 9 differently than shown. Likewise, unlike what is shown, components of the measuring system 20, in particular the deflection pulley 11, can not be encompassed by the housing 9. The pull cable 10 can enter and exit the housing through an opening.A guide or a seal can be provided at the opening of the housing 9 in order to enable the traction cable 10 to be guided as frictionlessly as possible without allowing dirt particles to enter the housing.

[0060] In Fig. Figure 2 schematically shows a measuring system 20 suitable for measuring the position of a measuring object 18 displaceable in a first direction R1 and having a reduction gear. The return spring 12 and the pull cable 10 are attached to a fastening point 16 of the measuring system. The return spring 12 is connected to the sensor 13. Another deflection pulley 19 is attached to the sensor 13. The deflection pulley 19, also referred to as a loose pulley, guides the pull cable 10 from the fastening point 16 to the deflection pulley 11. Due to the 180° deflection, the pull cable initially runs in direction R2 and, after the deflection, in the opposite direction. The directions R1 and R2 are orthogonal to one another: direction R1 is perpendicular / vertical and direction R2 is horizontal / horizontal. The reduction factor in this embodiment is 2. A change in the position of the measuring position 17 in the direction R1 results in a displacement of the sensor 13 in the direction R2 that is half as large.

[0061] In Fig. 3 and Fig. Figure 4 shows a device (scissor lift table) 21 comprising a table 18 with a scissor lift and an (integrated) measuring system consisting of a sensor 13, a sensor strip 14, a return spring 12, and two deflection pulleys 11, 19 for measuring height from one side. The measuring object is the table segment 18 and / or the surface of the table segment 18 of the scissor lift table 21.

[0062] In Fig. 3, the scissor lift table 21 is shown in its initial state or in a retracted state. The initial state typically refers to the state in which the table 17 has the lowest height A (in the y-direction of the coordinate system). The height A indicates the distance between the surface of the table 18 and the floor on which the scissor lift table 21 is positioned. The sensor strip 14 and the sensor 13 (as well as the return spring 12 and the deflection pulley 19) of the measuring system are arranged horizontally in the lower area of ​​the scissor lift table near the floor. In the initial state of the scissor lift table, the sensor 13 is in a maximally deflected position on the sensor strip. The maximum deflected position of the sensor 13 on the sensor band 13 corresponds to a distance S between the end of the sensor band 22, to which a return spring and / or the pull cable (attachment point 7) is attached, and the sensor 13.In other words, in the initial state, the distance A characterizing the measuring distance corresponds to a distance S characterizing the measuring position on the sensor tape. The minimum value of the height (distance A) corresponds to the maximum value of the sensor distance (distance S).

[0063] In Fig. Figure 4 shows the state in which the scissor lift table 21 is fully extended. In this maximum state, the maximum height of the table 17 from the ground, distance B, is reached. The maximum height (distance B) corresponds to the minimum sensor distance (distance T). When the scissor lift table is extended, the measuring distance (the height of the table) increases while the sensor distance (positioning of the sensor on the sensor strip compared to the initial state) is simultaneously adjusted.

[0064] The scissor lift kinematics can be used as a single scissor, as in Fig. 3 and Fig.4, or it can also be designed as a double or multiple scissor lift. Other lifting kinematics are conceivable, featuring a linear upward lifting movement. In addition to the position of the lifting table, the proposed measuring system can also enable the measurement and / or determination of the speed of the scissor lift table.

[0065] Finally, it should be noted once again that the figures of the measuring system shown are merely exemplary embodiments that can be modified in a variety of ways by a person skilled in the art without departing from the scope of the invention. For example, features of different exemplary embodiments can be combined (other than as shown). Furthermore, the use of the indefinite articles "a" or "an" does not exclude the possibility that the respective features may be present in multiple instances. Likewise, the term "system" does not exclude the possibility that the respective components consist of several interacting subcomponents, which may also be spatially distributed.

[0066] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

Claims

[1] Measuring system (20) for determining position information of a measuring position (17) of a measuring object (18), comprising a sensor band (14), a sensor (13) designed to detect position information on the sensor band (14), a traction cable (10) which transmits the measuring position (17) of the measuring object (18) to the sensor (13), at least one deflection pulley (11) designed to deflect the traction cable (10) from a first direction (R1) into a second direction (R2), at least one further deflection pulley (19) which deflects the traction cable (10). [2] Measuring system (20) according to claim 1, wherein the measuring system (20) is designed to measure a position change of the measuring position (17) of the measuring object (18) in the first direction (R1) by means of the sensor (13) by a position change of a position of the sensor (13) on the sensor band (14) in the second direction (R2). [3] Measuring system (20) according to one of the preceding claims, wherein the first direction (R1) is vertical and a second direction (R2) is horizontal. [4] Measuring system (20) according to one of the preceding claims, wherein the traction cable (10) is mechanically connected to the measuring object (18) and / or the sensor (13). [5] Measuring system (20) according to one of the preceding claims, wherein the measuring system (20) comprises a guide for guiding the sensor (13) on the sensor band (14). [6] Measuring system (20) according to one of the preceding claims, wherein the measuring system (20) comprises a return spring (12) which is mechanically connected to the sensor (13) and traction cable (10). [7] Measuring system (20) according to one of the preceding claims, wherein the measuring system (20) comprises a return spring (12) which is designed to apply a return force to the traction cable (10) and / or the sensor (13). [8] Measuring system (20) according to claim 7, wherein at least one deflection roller (11, 19) is mechanically connected to the sensor (13). [9] Measuring system (20) according to one of the preceding claims, wherein the traction cable (10) is attached to a non-movable attachment point (16) of the measuring system (20). [10] Measuring system (20) according to one of the preceding claims, wherein the measuring distance (S) on the sensor band (14) determined by the sensor (13) corresponds to an integer multiple of the position distance (B) of the measuring position (17). [11] Table (21) comprising a measuring system (20) according to one of the preceding claims, wherein the table (21) has a lifting device, in particular a scissor lifting device, by means of which the height of the table (21) can be adjusted in the first direction and wherein the height of the table can be determined by means of the measuring system (20). [12] Medical device, in particular for recording medical image data, comprising a table (21) according to claim 11 and / or a measuring system (20) according to one of claims 1 to 10.

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