Measuring device and method for measuring an object

Abstract

The invention relates to a measuring device (1) for measuring an object (O), having a housing (2) in which a rotatably mounted drum (4) is accommodated and having a longitudinal element (5) which can be rolled up onto the drum (4) and can be unwound therefrom and one end (7) of which is connected to a measuring pin (8), wherein at least one angle sensor (10) for detecting the orientation of the longitudinal element (5) in relation to a main part (11) and a length sensor (12) for detecting the longitudinal extent (E) of the longitudinal element (5) in an extended state (ZA) are provided; between the drum (4) and the measuring pin (8) is a measuring arm (13) which is hingedly connected to the main part (11) and guides the longitudinal element (5); the drum (4) is connected to a preloading device (14); and the preloading device (14) has an electric motor (15) which is connected to the drum (4) and is designed to apply a torque to the drum (4), the torque counteracting an extending movement of the longitudinal element (5) into the extended state (ZA).

Description

[0001] Measuring device and method for measuring an object

[0002] The invention relates to a measuring device for measuring an object according to the preamble of claim 1 and to a method for measuring an object with a measuring device according to the preamble of claim 13.

[0003] As is well known, measuring objects with a tape measure can be time-consuming and prone to errors, especially when the object has an irregular outer contour or is in hard-to-reach areas. In particular, when the object defines a recess into which a custom-made product needs to be inserted as precisely as possible, errors in measuring the recess lead to costly corrective measures.

[0004] Therefore, measuring devices are known from the prior art which are intended to simplify the measurement of objects.

[0005] EP 2 681 505 B1 discloses a device for measuring the area dimensions of an object. For this purpose, an elongated, flexible piece of material, in particular a measuring tape, with a probe at one of its ends, is arranged to be unwound on a roller. The unwound length of the measuring tape and its angle relative to a base of the device can be detected by means of two sensors. The roller is rotatably connected to the base about a vertical axis, which is arranged perpendicular to both a plane of the base and a rotational axis of the roller. A spring is preferably provided as a preloading means for winding the measuring tape onto the roller.

[0006] The accuracy of measurements with a pre-tensioned measuring tape depends, among other things, on the pre-tension force. If this force is too low, the measuring tape can sag due to gravity. If, on the other hand, the pre-tension force is too high, the mechanical support can deform or the measuring device can shift. In both cases, inaccurate measurement results are obtained. US 2011 / 131008 A1 discloses a positioning device, among other things for measuring a workpiece, with an extendable rope to the free end of which a handle is attached. For the measurement, the rope orientation and length are recorded. For this purpose, the positioning device has a base supported on a surface, a rotating support mounted thereon so as to be rotatable through any angle, and a tilting support mounted on the rotating support so as to be rotatable, i.e., tiltable, at an angle from -35 degrees to +92 degrees.When the rope is moved, an angle displacement sensor detects the deflection of the rope from an aligned position. A rotary servomotor then rotates the rotating carriage, and a tilting servomotor adjusts the tilting carriage, until the aligned position is restored. The rope is wound on a pulley and held at a predetermined tension by a servomotor on the pulley.

[0007] US Patent 2008 / 072443 Al concerns transducers that detect the extension / retraction and angular orientation of a rope to determine the position of a rope end in spatial coordinates. A swivel frame is mounted on a housing, supporting a swiveling rope extension arm and two pulleys. A rope is held within the extension arm. A first sensor is attached to the swivel frame. A second sensor on the housing detects the rotational position of the swivel frame. A third sensor on the housing detects the rotational position of a rope retraction drum. The rope retraction drum has a rope retraction mechanism, such as a spring or a motor.

[0008] EP 2 681 505 Bl relates to a device for measuring the surface dimensions of an object, comprising an elongated, flexible piece of material mounted on a roll and equipped with a probe at its end. The unrolled distance of the material and its angle relative to a base are detected by means of two sensors. The material is wound onto the roll in overlapping layers. Therefore, the diameter of the material on the roll decreases as it is unwound. The roll is pivotable vertically via a swivel arm and is lowered as the material unwinds and raised again as it winds back up.

[0009] The object of the invention is to provide a measuring device and a measuring method of the type mentioned above, which avoids or at least reduces the disadvantages known from the prior art. In particular, the measuring device and the measuring method should enable measurements with improved accuracy in a short time. Furthermore, the measuring device should be as small and lightweight as possible. The measuring method should also be performable by persons who have no knowledge of subsequent correction calculations.

[0010] For this purpose, the invention provides a measuring device as defined in claim 1 and a measuring method as defined in claim 13. Advantageous embodiments and further developments are specified in the dependent claims.

[0011] Regarding the measuring device, the problem is solved by the drum being adjustable along its longitudinal axis and by providing a feed device connected to the drum. This feed device adjusts the drum along its longitudinal axis during rotation such that the retractable longitudinal element is wound onto the drum in a single layer when retracted. The measuring device serves to measure an object. The object can be a portable or stationary item, of which a two-dimensional planar area or a three-dimensional spatial area, or a part thereof, is to be measured. The planar or spatial area can be located inside or outside a building.For example, the measuring device is used to measure room dimensions, such as niches, stairwells, window or door openings, or parts of furniture that are to be fitted with a product to be manufactured with the greatest possible accuracy. The measuring device has a housing in which a drum, rotatably mounted about a longitudinal axis, is contained. The measuring device also has a longitudinal element that can be wound onto the drum, with a first end and a second end. This longitudinal element is wound onto the drum in a retracted state and is partially unwound from the drum in at least one extended state. The longitudinal element, which can be wound onto and unwound, is attached to the drum at its first end, guided through an opening in the housing, and connected to a measuring pin at its second end, which is positioned outside the housing during a measuring process.The measuring pin is designed for movement by a user, specifically for movement to at least one point or along at least one part of the object to be measured, i.e., to positions whose angle and distance to the measuring device are to be recorded. For example, the user can position the measuring pin at corners of an object to record their position, or the measuring pin can be guided at least along part of an edge of the object or along the circumference of the object to record the object's contour. When the user moves the measuring pin to the position to be measured, the retractable longitudinal element is unwound at least a short distance from the drum and is in its extended state.Preferably, the retractable longitudinal element is connected to a rounded end of the measuring pin in order to minimize the distance between the second end of the retractable longitudinal element and the rounded end of the measuring pin, thereby minimizing measurement inaccuracies caused by tilting of the measuring pin. The measuring pin can be made of, for example, plastic or metal. The measuring device also includes a base body that supports the housing and is fixed relative to the object. At least one angle sensor is provided to detect the two-dimensional or three-dimensional orientation of the extended retractable longitudinal element relative to the base body, which supports the housing and is fixed relative to the object. A length sensor is provided to detect the longitudinal extent of the retractable longitudinal element in the extended state relative to the retracted state.The longitudinal extent of the retractable longitudinal element is defined here as the extent of the section of the retractable longitudinal element extended longitudinally towards the object. The base body has a base surface, which can be formed by a flat surface or by the base surfaces of several feet. The base surface lies in a principal plane, which is generally, but not necessarily, a horizontal plane and can be used as a reference for directional information in the following description. The measuring device also has a measuring arm between the drum and the measuring pin, which is pivotally connected to the base body and guides the retractable longitudinal element. For example, the measuring arm is connected to the base body via a ball joint. The measuring arm preferably also extends through the opening in the housing and preferably guides the retractable longitudinal element out of the housing through the opening in the housing.The measuring arm is preferably manufactured with a low weight so that it can be deflected with low forces acting on the retractable longitudinal element and with minimal oscillation. The length of the measuring arm is preferably between 5 cm and 20 cm. A shorter length would impair the guiding properties of the measuring arm, while a longer length would make measurements close to the housing more difficult. Preferably, the measuring arm is designed as a tube in which the retractable longitudinal element is housed, and in particular, the tube is elastic in the radial direction, i.e., expandable. For precise detection of the orientation of the retractable longitudinal element, minimal clearance is advantageously provided between the inner diameter of the measuring arm and the outer diameter of the retractable longitudinal element, with the inner diameter of the measuring arm being preferably...The tube's outer diameter deviates by no more than 0.2 mm from the outer diameter of the coilable longitudinal element. Preferably, no clearance is provided between the inner diameter of the measuring arm and the outer diameter of the coilable longitudinal element, in which case the inner diameter of the measuring arm, in a state prior to the coilable longitudinal element's insertion into the measuring arm, may be up to 0.2 mm smaller than the outer diameter of the coilable longitudinal element. The measuring device also includes a pre-tensioning device to which the drum is connected. The pre-tensioning device is designed to pre-tension the coilable longitudinal element into the retracted state with a retraction force during an operating state of the measuring device. To perform a measurement, the user pulls the coilable longitudinal element out of the housing with a greater pull-out force against the retraction force.

[0012] To maintain the preload of the measuring device as constant as possible at a defined preload value during operation, both while the coilable longitudinal element is being extended to its maximum length and over several years of operation, the preloading device is designed to include an electric motor connected to the drum. This motor is configured to apply a torque to the drum that opposes the extension of the coilable longitudinal element. In contrast, return springs, particularly coil springs, are known in the art for generating the preload. However, these spring elements do not exert a constant spring force on the drum over the maximum extension length of the coilable longitudinal element; that is, the known spring elements do not have a perfectly horizontal spring characteristic.Furthermore, the known spring elements exert a preload on the drum that varies with age. Maintaining a predefined preload as precisely as possible is essential for achieving accurate measurement results. The preload acting on the drum influences both angular deviations caused by the force of gravity on the coiled longitudinal element and the measuring arm during measurement, and the elongation of the coiled longitudinal element during measurement. A varying preload can therefore cause different measurement errors depending on the extension length of the coiled longitudinal element, i.e., when the coiled longitudinal element is pulled out of the housing to different distances. This disadvantage is avoided with the electric motor, as it generates a defined preload, independent of the extension length of the coiled longitudinal element in its extended state and independent of the age of the electric motor.Furthermore, the electric motor is essentially maintenance-free.

[0013] In order to accurately measure the longitudinal extent of the retractable element in its extended state using the length sensor, the invention provides that the drum is adjustable along its longitudinal axis and that a feed device connected to the drum is formed. This feed device adjusts the drum along its longitudinal axis during rotation such that the retractable element is wound onto the drum in a single layer when retracted. Thus, the radius of the portion of the retractable element wound onto the drum remains constant, and a clear relationship exists between the drum's angle of rotation and the longitudinal extent of the retractable element, which is at least partially extended from the housing. The feed device achieves this by adjusting the drum axially during its rotation.For example, the feed mechanism can have a threaded rod attached to the housing and a nut attached to the drum that engages the thread of the threaded rod, so that the nut is guided along the threaded rod during rotation of the drum. The thread pitch of the threaded rod is preferably designed such that the distance between the turns of the coilable longitudinal element on the drum, in the axial direction of the drum, is at most equal to the diameter of the coilable longitudinal element. The turns can also be in contact with each other. The circumferential surface of the drum can preferably have receiving grooves for the turns of the coilable longitudinal element.

[0014] When, in the course of the description, reference is made to location and direction specifications such as "top," "bottom," "front," "back," "longitudinal direction," "vertical direction," or "transverse direction," these specifications refer to an intended state of use of the measuring device. In the intended state of use, the measuring device is arranged with its base body on a surface. As mentioned at the outset, the base body lies in a main plane. The vertical direction is perpendicular to the main plane, and the transverse direction runs in a plane parallel to the main plane and essentially perpendicular to the longitudinal extent of the longitudinal element extending from the housing. The term "vertical" means in the direction of gravity, from "top" to "bottom," or vice versa. If the measuring device is to be used in a different position, the location and direction specifications must be adjusted accordingly.

[0015] According to a preferred embodiment of the invention, a motor controller connected to the electric motor, in particular a brushless DC motor, is configured to operate the electric motor with at least one setpoint torque for extending the retractable longitudinal element into the extended state and, in particular, with at least one different setpoint torque for retracting the retractable longitudinal element into the retracted state. The motor controller is therefore configured to drive the electric motor. The electric motor exerts at least a defined torque of a setpoint value on the drum. The motor controller can be configured to operate the electric motor with exactly one setpoint torque for extending the retractable longitudinal element into the extended state, in which case the torque is constant over the entire extension length of the retractable longitudinal element.The motor control can also be configured to operate the electric motor with, for example, two torque setpoints for extending the retractable longitudinal element into the extended position. In this case, a first setpoint can be used to bring the measuring pin closer to the position to be measured, and a different, and in particular larger, second setpoint can be used for the metrological measurement of the position to be measured. Thus, due to the lower first setpoint, the retractable longitudinal element can be pulled out of the housing with minimal effort and therefore particularly easily, while the actual measurement process can be carried out with the larger second setpoint to increase the preload of the retractable longitudinal element and thereby reduce any sagging caused by gravity.The motor control can also be configured to operate the electric motor with at least one setpoint torque for retracting the coilable longitudinal element into the retracted state, which differs from the setpoint for extending the coilable longitudinal element into the extended state. In particular, the setpoint for retraction into the housing can be larger, for example, 1.5 to 2.5 times larger, than the setpoint for extension from the housing. Furthermore, the setpoint at the beginning of the coiling process can be lower than at the end. For good controllability of the electric motor, it is advantageous if the electric motor is a brushless DC motor.

[0016] It is particularly advantageous if the motor controller is connected to an input device and configured to operate the electric motor with torque setpoints adjustable via the input device. The input device can be located on the housing of the measuring device or at a distance from the housing and can be connected to the motor controller via a preferably wireless radio interface. The input device can include buttons or a touchscreen for selecting predefined torque setpoints. For example, the input device can be a laptop or a smartphone and, in particular, allow the input of at least one user-selected setpoint.

[0017] To increase measurement accuracy, the input device can be configured to accept at least two target torque values ​​for extending the retractable longitudinal element into the extended state, and preferably at least two different target torque values ​​for retracting the retractable longitudinal element into the retracted state. This allows the dimensions of the same object to be measured multiple times, with each measurement performed using a different target torque value. For example, at least two measurements can be performed on the same object, with the electric motor being operated with at least two different target torque values ​​for extending the retractable longitudinal element and preferably with at least two different target torque values ​​for retracting the retractable longitudinal element.For each target torque value for extending the retractable longitudinal element, the object dimensions of the same object can be recorded using the angle sensor and the length sensor. Final object dimensions can then be calculated from the various recorded object dimensions, for example, by averaging. In this way, the influence of the drum's torque on the measurement accuracy is reduced.

[0018] A memory unit can be provided inside or outside the housing of the measuring device for storing individual object measurements, several different recorded object measurements, and / or the final object measurements. A processing unit, in particular a processor, can be provided inside or outside the housing of the measuring device for processing the object measurements, for example, calculating the average value.

[0019] For measuring the longitudinal extension of the retractable element in the extended state relative to the retracted state, it is advantageous if the length sensor is connected to the drum and designed to detect the drum's rotational position about its longitudinal axis. In a particularly simple embodiment, the length sensor can comprise several, for example, three digital Hall sensors. Preferably, however, the length sensor is designed to detect the drum's rotational position even when the drum is stationary, and preferably with a resolution of at least 8 bits, i.e., at least 2 8 = 256 intervals, in particular with a resolution of at least 14 bits, i.e. at least 2 14= 16384 intervals. A resolution of 14 bits corresponds to approximately 0.01 mm resolution of the longitudinal extent for a drum diameter of 60 mm. The current extension length of the retractable longitudinal element can be determined from the rotational position of the drum detected by the length sensor. Preferably, the length sensor is an absolute sensor, which, unlike an incremental sensor (also called a relative sensor), detects the rotational position of the drum without an initialization process or a calibration process after switching on.

[0020] To determine the orientation of the longitudinal element extended from the housing relative to the base body, it is preferred that the measuring arm is articulated to the base body in a vertical direction of the housing, and that the at least one angle sensor includes a height-angle sensor connected to the measuring arm, which is configured to detect an angle of the measuring arm in the vertical direction relative to the base body. As mentioned above, the vertical direction is perpendicular to the main plane, which is defined by the base surface of the base body. Therefore, if the measuring device is tilted, the vertical direction also changes. For the articulated connection of the measuring arm to the base body in the vertical direction, a height-angle joint axis can be provided in a plane parallel to the main plane, about which the measuring arm pivots. Alternatively, the measuring arm can be connected to the base via a ball joint.The height-angle sensor connected to the measuring arm can include a height-angle ring magnet and a cooperating height-angle magnetic field sensor. If a relative sensor is used as the height-angle sensor, its initialization occurs after each restart of the measuring device by the user through a mandatory movement of the measuring arm to its upper and lower end positions in the height direction. Alternatively, the height-angle sensor can be designed as an absolute sensor. The height-angle sensor detects an angle of the measuring arm, and thus of the retractable longitudinal element guided by the measuring arm, in the height direction relative to the base body, specifically relative to the base body's surface. The angle of the pivotable measuring arm in the height direction can range from -45 degrees to +90 degrees.To detect the orientation of the longitudinal element extended from the housing relative to the base body, it is further preferred that the measuring arm is pivotally connected to the base body in a transverse direction of the housing, and that the at least one angle sensor has a transverse angle sensor connected to the measuring arm, which is configured to detect an angle of the measuring arm in the transverse direction relative to the base body. As mentioned above, the transverse direction runs in a plane parallel to the main plane, which is defined by the base surface of the base body, and essentially perpendicular to the longitudinal extent of the longitudinal element extended from the housing. For the pivotal connection of the measuring arm to the base body in the transverse direction, a transverse angle pivot axis can be provided perpendicular to the main plane, about which the measuring arm pivots. Alternatively, the measuring arm can be connected to the base via a ball joint.The transverse angle sensor connected to the measuring arm can include a transverse angle ring magnet and a cooperating transverse angle magnetic field sensor. For a cost-effective design, the transverse angle sensor can be configured as a relative sensor, which is initialized after each restart of the measuring device by the user through a mandatory movement of the measuring arm to its lateral end positions in the transverse direction. Alternatively, the transverse angle sensor can be configured as an absolute sensor to avoid the initialization process. The transverse angle sensor detects an angle of the measuring arm, and thus of the retractable longitudinal element guided by the measuring arm, in the transverse direction with respect to the base body, particularly with respect to the base body's surface.

[0021] If the housing is rotatably mounted on the base body about a housing axis of rotation, the housing can rotate along with the rollable longitudinal element when it is deflected in the transverse direction. This prevents twisting of the rollable longitudinal element when it is deflected in the transverse direction. Furthermore, the rollable longitudinal element, which should be extended as straight as possible for measurement, can be deflected by a larger angle in the transverse direction than would be permitted by the limited opening angle of the opening in a stationary housing. A non-rotating housing would therefore adversely restrict the usable angle of the rollable longitudinal element in the transverse direction for measurement. The housing axis of rotation is preferably perpendicular to the main plane. Preferably, the housing axis of rotation is designed for an unlimited rotation angle of the housing, i.e., a rotation of the housing by less than or more than 360°, with respect to the base body.

[0022] It is particularly advantageous if an auxiliary motor is provided for rotating the housing about the housing axis of rotation, an auxiliary sensor connected to the housing is designed to detect a housing rotation angle of the housing with respect to the base body or with respect to the measuring arm, and an auxiliary motor control connected to the auxiliary motor, the transverse angle sensor and the auxiliary sensor is designed to rotate the housing via the electric auxiliary motor until the housing rotation angle detected by the auxiliary sensor matches the angle of the measuring arm detected by the transverse angle sensor, if the auxiliary sensor is designed to detect the housing rotation angle of the housing with respect to the base body, or if the auxiliary motor control is designed to rotate the housing via the electric auxiliary motor until the housing rotation angle detected by the auxiliary sensor is zero, if the auxiliary sensor is designed to detect the housing rotation angle of the housing with respect to the measuring arm.This allows the housing to be guided in the transverse direction by the auxiliary motor, following the deflection of the measuring arm and the retractable longitudinal element guided within it. The auxiliary motor is preferably activated by pivoting the measuring arm in the transverse direction relative to the housing and deactivated when the rotated housing reaches a defined rest position relative to the measuring arm. This eliminates the need for manual rotation of the housing into the rest position via the measuring arm, thereby reducing the load on the measuring arm and ensuring that the retractable longitudinal element travels in a straight line, as the transverse movement of the measuring arm is not affected by the edge of the opening in the housing, the inertia of the housing, or the friction of the housing's pivot bearing. The auxiliary motor is preferably an electric motor.The auxiliary sensor connected to the housing can include a disc magnet and a cooperating housing angle magnetic field sensor. Preferably, the auxiliary sensor is designed as an absolute sensor. The auxiliary motor, the transverse angle sensor, and the auxiliary sensor are preferably connected to the auxiliary motor control unit, which is configured to rotate the auxiliary motor depending on the measured values ​​of the transverse angle sensor and the auxiliary sensor. Depending on the embodiment, the auxiliary sensor can detect the housing rotation angle with respect to the base body or with respect to the measuring arm. If the auxiliary sensor is configured to detect the housing rotation angle with respect to the base body, the auxiliary motor control unit is configured to rotate the housing via the electric auxiliary motor until the housing rotation angle detected by the auxiliary sensor is aligned with the angle of the measuring arm detected by the transverse angle sensor.This returns the housing to its rest position, in which the housing rotation angle measured relative to the base body is equal to the angle of the measuring arm measured relative to the base body in the transverse direction. If, however, the auxiliary sensor is configured to detect the housing rotation angle relative to the measuring arm, the auxiliary motor control is configured to rotate the housing via the electric auxiliary motor until the housing rotation angle detected by the auxiliary sensor is zero. In the resulting rest position of the housing, the housing rotation angle measured relative to the measuring arm is zero. A housing rotation angle relative to the base body is defined as an angle between a longitudinal direction of the housing, which extends from the housing rotation axis through the center of the opening in the housing and in a plane parallel to the main plane, and a defined longitudinal direction of the base body.Similarly, a housing rotation angle of the housing in relation to the measuring arm is understood to be an angle between the longitudinal direction of the housing and a projection of the longitudinal direction of the measuring arm onto the main plane.

[0023] For precise guidance of the retractable longitudinal element within the housing, it is preferred that a deflection roller be provided in the housing to redirect the retractable longitudinal element from the measuring arm to the drum, and in particular that the retractable longitudinal element runs between the deflection roller and the drum along the housing's axis of rotation. The deflection roller thus guides the retractable longitudinal element onto the drum independently of any deflection of the measuring arm. If the retractable longitudinal element runs between the deflection roller and the drum along the housing's axis of rotation, disruptive torques on a measuring arm mount during a transverse deflection of the measuring arm can be avoided.

[0024] To prevent the coilable longitudinal element from unintentionally unwinding from the drum between measurements, i.e., in a state where preload on the coilable longitudinal element is not strictly necessary, a locking device is preferably provided. This device blocks rotation of the drum in a locked state and releases rotation in a released state. The locking device can be moved to the locked state manually by a user or automatically as a result of the measuring device being switched off. Likewise, the locking device can be moved to the released state manually by a user or automatically as a result of the measuring device being switched on. A particularly reliable design may provide that the locking device has an electrically adjustable locking element, which is engaged at least when the measuring device is de-energized.When the measuring device is switched off, it is biased into an engagement with the drum that blocks it, and is released from this engagement with the drum in at least one electrically powered state of the measuring device, i.e., when the measuring device is switched on. As an alternative to a positive locking mechanism, the locking device can, for example, force-lock the rotation of the drum in the locked state.

[0025] To achieve high measuring accuracy, the retractable longitudinal element can be a rope, preferably a metal rope consisting of a multitude of metal strands, with a preferably essentially circular cross-section. A rope offers the advantage of high flexibility in directions deviating from the longitudinal direction of the rope, while simultaneously exhibiting low longitudinal elongation. The rope can be a plastic rope with or without plastic strands, for example, a nylon rope; however, a metal rope with metal strands, for example, a steel rope, is preferred. A circular cross-section offers the advantage that the rope, in the respective longitudinal section adjacent to the measuring arm, lies as completely as possible along its circumference against an inner surface of the measuring arm and can thus be guided through the measuring arm precisely and without jamming.

[0026] A heating device connected to the housing, with a heating element designed to emit heat, is particularly preferred. Preferably, the heating device is arranged on or inside the housing. The heating device makes it possible to maintain the temperature in the housing, especially the drum temperature, at a defined operating temperature. The temperature in the housing, particularly the drum temperature, has a significant influence on the accuracy of the length measurement when the longitudinal extension of the coilable element is measured indirectly via the rotation of the drum axis. For example, with 18 turns of the coilable element and a diameter change of the drum of 0.0177 mm, a length error of 1 mm results.If the drum is made of aluminium, it should be noted that, due to the large coefficient of thermal expansion of aluminium, depending on the geometry of the drum, this length error can already be caused by a temperature change of 5 to 10°C.

[0027] Drums made from alternative materials with very low coefficients of expansion (e.g. Inconel®) are significantly more expensive to manufacture.

[0028] Preferably, the heating element of the heating device can be the electric motor connected to the drum. During operation, the electric motor generates heat, which leads to a temperature increase in the drum and the housing. Thus, by adjusting the torque of the electric motor, the desired operating temperature can be set and regulated during operation of the measuring device. Even when no measurement is active, the torque of the electric motor can be adjusted so that the same desired operating temperature is always maintained under the influence of varying ambient temperatures, whereby the operating temperature should be correspondingly higher than the ambient temperature. For example, the operating temperature in the housing, and therefore that of the drum, is in the range of 40°C to 45°C and is set with a maximum deviation of 2°C, preferably a maximum deviation of 1°C.Active temperature control within the housing also increases the accuracy of other sensors, such as the angle sensor or accelerometers, because it maintains the operating temperature that the measuring device had during a previous calibration process. Without such temperature control, the calibration process would be more complex, as it would have to be performed at different temperatures, and the influence on the calibration parameters would have to be interpolated in the software. Preferably, the longitudinal element near the measuring pin has a closure that can be used to separate the measuring pin from the longitudinal element. This closure can also serve as a stop on the measuring arm to limit the retraction of the longitudinal element into the housing caused by the electric motor.If a locking device is provided, once the locking device is deactivated, a temperature-dependent torque can be generated at the electric motor, even if no measurement is taken to adjust the operating temperature.

[0029] It is also advantageous if the heating device has a heating control unit and a temperature sensor, which is connected to the heating element via the heating control unit, and in particular to the electric motor via a motor control unit connected to the electric motor. The temperature sensor can measure the temperature inside the housing, especially the temperature of the drum. Depending on the temperature measured by the temperature sensor, the heating element can be controlled by the heating control unit, thereby regulating the heat output of the heating element. Specifically, the torque of the electric motor can be regulated by the motor control unit depending on the temperature detected by the temperature sensor.

[0030] As mentioned at the beginning, the invention also relates to a method for measuring an object with a measuring device.

[0031] Regarding the method for measuring an object with a measuring device, the problem initially posed is solved by adjusting the drum along its longitudinal axis by a feed device during rotation about the drum's longitudinal axis such that the coilable longitudinal element is wound onto the drum in a single position when transitioning to the retracted state. The measuring device comprises a housing and a drum rotatably mounted about a longitudinal axis within the housing. The measuring device also includes a coilable longitudinal element having a first end and a second end, which can be wound onto the drum in a retracted state before measurement and is moved by a user into at least one extended state for measurement, and is partially unwound from the drum during the transition to the extended state.The retractable longitudinal element is attached to the drum at one end, guided through an opening in the housing, and connected at the other end to a measuring pin. To perform the measurement, the user moves the pin against the force of a preload acting on the drum to at least one position to be measured, thereby tensioning the retractable longitudinal element. For the measurement, at least one angle sensor detects the orientation of the retractable longitudinal element relative to a base body that supports the housing and is fixed relative to the object. A length sensor detects the longitudinal extension of the retractable longitudinal element in its extended state relative to its retracted state. For precise measurement, the retractable longitudinal element is guided by a measuring arm located between the drum and the measuring pin and articulated to the base body.To maintain a defined preload on the drum, the preload is generated by an electric motor connected to the drum, which applies a torque to the drum that opposes the extension of the coilable longitudinal element into the extended state. During rotation around its longitudinal axis, the drum is adjusted along this axis by the feed mechanism in such a way that the coilable longitudinal element is wound onto the drum in a single layer when transitioning to the retracted state. The coils of the coilable longitudinal element are thus arranged side by side, not one above the other, on the drum. This ensures that all coils of the coilable longitudinal element have the same radius. Therefore, a processing unit of the measuring device can determine the longitudinal extent of the coilable longitudinal element, i.e.,The length by which the retractable longitudinal element was pulled out of the housing can be determined particularly accurately via the rotation angle of the drum.

[0032] Regarding the characteristics of the method, reference is also made to the preceding description of the measuring device, insofar as this is helpful for understanding the method and insofar as characteristics of the method can be derived from this description of the measuring device. Likewise, with regard to the characteristics of the measuring device, reference is also made to the description of the method.

[0033] According to a preferred embodiment of the method, the electric motor is operated with at least one setpoint torque for extending the coilable longitudinal element into the extended state and, in particular, with at least one different setpoint torque for retracting the coilable longitudinal element into the retracted state, especially with torque setpoints adjustable via an input device. The electric motor can be controlled by a motor controller. Accordingly, the drum can be subjected by the electric motor to at least one setpoint torque for extending the coilable longitudinal element and, in particular, with at least one different setpoint torque for retracting the coilable longitudinal element.The torque for extending the retractable longitudinal element into the extended position can be kept constant over the entire extension length of the retractable longitudinal element. Likewise, the drum can be subjected to multiple, for example, two target torque values ​​for extending the retractable longitudinal element into the extended position. For instance, a first target value is applied for approaching the measuring pin to the position to be measured, and a different, and in particular larger, second target value is applied for the metrological measurement of the position to be measured. The drum can also be subjected to at least one target torque value for retracting the retractable longitudinal element into the retracted position, which differs from the target value for extending the retractable longitudinal element into the extended position and is, in particular, larger than the target value for extension.If an input device is provided for a user, adjustable or inputtable target torque values ​​can be transmitted to the motor control via the input device. The input device can be located on the housing of the measuring device or at a distance from the housing.

[0034] Since the drum's torque influences the measured values, it is preferred that the drum's torque be measured and the object dimensions acquired by the angle and length sensors be corrected using the torque measurement. This correction can be performed by suitable software, which may be stored in memory within the housing or in external memory. The correction of the acquired object dimensions can be achieved by increasing or decreasing the measured longitudinal extension of the coilable element, with the increase or decrease depending on the torque. At high torques, the undesired extension of the coilable element predominates; therefore, the increase is greater the higher the torque and thus the tensile force on the coilable element.At low torques, however, an undesirable sagging of the rollable longitudinal element due to gravity predominates. Therefore, the reduction is greater the lower the torque and thus the tensile force on the rollable longitudinal element. The object dimensions measured by the angle sensor can also be corrected depending on the torque reading. For example, a low torque can lead to an underestimation of the vertical angle due to the sagging of the rollable longitudinal element. Therefore, the measured angle can be increased by correction, depending on the torque value.

[0035] It is particularly advantageous if, for multiple measurements of object dimensions of the same object, the electric motor is operated with at least two different target torque values ​​for extending the retractable longitudinal element into the extended state and preferably with at least two different target torque values ​​for retracting the retractable longitudinal element into the retracted state. For each target torque value for extending the retractable longitudinal element, the object dimensions of the same object are recorded with the angle sensor and the length sensor, and final object dimensions are calculated from the different recorded object dimensions. For example, a final mean value of the longitudinal extent can be calculated from the several longitudinal extents recorded with the length sensor, and a final mean value of the orientation can be calculated from the several orientations recorded with the angle sensor.Of course, alternative calculation methods can be used. In this way, the influence of the drum preload on the determined object dimensions can be reduced.

[0036] Furthermore, it can be provided that the housing is rotated about a housing rotation axis by an auxiliary motor, wherein an auxiliary sensor connected to the housing detects a housing rotation angle of the housing with respect to the base body or with respect to the measuring arm, a transverse angle sensor detects an angle of the measuring arm in a transverse direction of the housing with respect to the base body, and an auxiliary motor controller connected to the auxiliary motor, the transverse angle sensor and the auxiliary sensor rotates the housing via the electric auxiliary motor until the housing rotation angle detected by the auxiliary sensor matches the angle of the measuring arm detected by the transverse angle sensor, if the auxiliary sensor detects the housing rotation angle of the housing with respect to the base body, or the auxiliary motor controller rotates the housing via the electric auxiliary motor until the housing rotation angle detected by the auxiliary sensor is zero.If the auxiliary sensor detects the housing rotation angle relative to the measuring arm, then a housing rotation angle and an angle of the measuring arm in a transverse direction of the housing can be detected and compared. If the housing rotation angle and the angle of the measuring arm in the transverse direction are measured relative to the base body, and there is a discrepancy between the two angles, the housing is rotated by the auxiliary motor until the housing rotation angle and the angle of the measuring arm in the transverse direction are equal. Conversely, if the housing rotation angle is measured relative to the orientation of the measuring arm in the transverse direction, and the housing rotation angle is not zero degrees, the housing is rotated by the auxiliary motor until...until the housing rotation angle is zero degrees. In the rotated state, a longitudinal direction of the housing and a projection of the longitudinal direction of the measuring arm onto the main plane are thus aligned parallel to each other.

[0037] Preferably, the drum is heated by a heating element of a heating device designed to emit heat. This allows the temperature in the housing, and in particular the temperature of the drum, to be maintained at a defined operating temperature. The heating device can be connected to the housing.

[0038] Preferably, the drum is heated by an electric motor powered by electricity. To achieve a predetermined operating temperature at the drum, the torque of the electric motor, and thus its heat output, can be adjusted, and in particular, regulated. This adjustment, especially regulation of the torque, can be carried out when no measurement is active, i.e., between or before measurements. In this way, the torque of the electric motor can be adjusted so that, under the influence of different ambient temperatures, the same predetermined operating temperature is always maintained in the housing, and in particular at the drum.

[0039] If an activatable and deactivatable locking device is provided, the adjustment, in particular the control of the torque, can be carried out after deactivating the locking device.

[0040] It is particularly advantageous if the temperature inside the housing, especially the drum temperature, is measured with a temperature sensor, compared to the predetermined operating temperature, and the torque of the electric motor is adjusted until the temperature measured by the sensor is within a tolerance range around the operating temperature. This tolerance range can be 2 °C, or more specifically, 1 °C.

[0041] The invention will be further explained below with reference to preferred, non-limiting embodiments and the drawings. The drawings show:

[0042] Fig. 1 shows a measuring device according to the invention and an object to be measured, in simplified representation;

[0043] Fig. 2 shows the measuring device from Fig. 1 in a perspective sectional view, in which essential components are shown, without the feed device for the sake of clarity;

[0044] Fig. 3 shows the measuring device from Fig. 1 in a side sectional view, in which an object to be measured is also shown;

[0045] Fig. 4 shows the measuring device from Fig. 1 from the front, in a sectional view;

[0046] Fig. 5 is a perspective sectional view of the measuring device from Fig. 1, in which a motor control and an input device are additionally shown;

[0047] Fig. 6 shows the measuring device from Fig. 5 in a side sectional view;

[0048] Fig. 7 is a perspective sectional view of the measuring device from Fig. 5, in which the length sensor is shown on the drum;

[0049] Fig. 8 shows the measuring device from Fig. 7 in a side sectional view;

[0050] Fig. 9 shows the perspective sectional view of the measuring device from Fig. 7, in which a deflection of the measuring arm in a vertical direction and in a transverse direction of the housing is shown;

[0051] Fig. 10 shows the measuring device from Fig. 9 in a side sectional view;

[0052] Fig. 11 shows the measuring device from Fig. 9 from the front, in a sectional view;

[0053] Fig. 12 shows a perspective sectional view of the measuring device from Fig. 9, in which an auxiliary motor, an auxiliary sensor and an auxiliary motor control are additionally shown;

[0054] Fig. 13 shows the measuring device from Fig. 12 in a side sectional view;

[0055] Fig. 14 shows a perspective sectional view of the measuring device from Fig. 12, in which the feed device and a heating device are also shown;

[0056] Fig. 15 shows the measuring device from Fig. 14 in a side sectional view;

[0057] Fig. 16 shows a perspective sectional view of the measuring device from Fig. 14, in which a locking device is additionally shown, with the heating device having the electric motor as a heating element;

[0058] Fig. 17 shows a more precise perspective sectional view of the measuring device from Fig. 16;

[0059] Fig. 18 shows the measuring device from Fig. 16 in a side sectional view;

[0060] Fig. 19 shows the measuring device from Fig. 16 from the front, in a sectional view;

[0061] Fig. 20 shows an exemplary block diagram of the measuring device; and

[0062] Fig. 21 shows a flowchart for a method for measuring an object with the measuring device.

[0063] It should be noted that Figures 1 to 19 are not necessarily drawn to scale. Furthermore, for the sake of simplicity, not all components of the measuring device are shown in all figures.

[0064] Figures 1 and 2 together show a measuring device 1 for measuring an object 0. The measuring device 1 has a housing 2 in which a drum 4 is rotatably mounted about a longitudinal axis 3. The drum 4 preferably has a cylindrical shell. The measuring device 1 also has a rollable longitudinal element 5 with a first end 6 and a second end 7. The rollable longitudinal element 5 is wound onto the drum 4, for example onto the cylindrical shell, in a retracted state ZE (see Figure 13) and partially unwound from the drum 4 in at least one extended state ZA. The retracted state ZE is preferably present after the measuring device 1 has been switched on.Preferably, the second end 7 of the retractable longitudinal element 5 protrudes a short distance from the housing 2 in the retracted state ZE, but the retractable longitudinal element 5 has not yet been pulled out of the housing 2 by applying a tensile force. As soon as the retractable longitudinal element 5 has been pulled out of the housing 2 a short distance by applying a tensile force, it is in an extended state ZA. It is evident that any number of extended states ZA exist between the retracted state ZE and a maximally extended state of the retractable longitudinal element 5. The retractable longitudinal element 5 is attached to the drum 4 at its first end 6 and connected at its second end 7 to a measuring pin 8, which is intended for movement by a user (not shown in the figures).Between the first end 6 and the second end 7, the retractable longitudinal element 5 is guided through a front opening 9 in the housing 2. The retractable longitudinal element 5 is preferably a rope, preferably a metal rope consisting of a plurality of metal strands, with a preferably substantially circular cross-section. The measuring device 1 also has at least one angle sensor 10 for detecting a planar or spatial orientation of the retractable longitudinal element 5 with respect to a base body 11 supporting the housing 2 and fixed with respect to the object 0. Figures 1 to 8 show a single angle sensor 10 for detecting a planar orientation of the retractable longitudinal element 5, and Figures 9 to 19 show two angle sensors 10 for detecting a spatial orientation of the retractable longitudinal element 5.To perform the measurement, the base body 11 is fixedly positioned on a horizontal, inclined, or vertical surface. The measuring device 1 further comprises a length sensor 12 for detecting the longitudinal extension E of the retractable longitudinal element 5 in the extended state ZA relative to the retracted state ZE. The longitudinal extension E of the retractable longitudinal element 5 is thus the length by which the user pulls the retractable longitudinal element 5 out of the housing 2 by applying a tensile force. The length sensor 12 is preferably connected to the drum 4 (see Figures 7 to 19) and is designed to detect the rotational position of the drum 4 about its longitudinal axis 3. The measuring device 1 also has a measuring arm 13, pivotally connected to the base body 11 and guiding the retractable longitudinal element 5, between the drum 4 and the measuring pin 8. In Figs. 1 to 6, the length sensor 12 is connected to the measuring arm 13.In the illustrated examples, the measuring arm 13 is designed as a tube in which a section of the rollable longitudinal element 5 is received. The drum 4 is connected to a pre-tensioning device 14 of the measuring device 1 in order to pull the rollable longitudinal element 5 out of the housing 2 against a pre-tensioning force applied by the pre-tensioning device 14 and to retract it back into the housing 2 by the same pre-tensioning force. The pre-tensioning device 14 has an electric motor 15 connected to the drum 4, which is arranged to apply a torque to the drum 4 that opposes the extension of the rollable longitudinal element 5 into the extended state ZA. In the illustrated examples, the electric motor 15 is arranged outside the drum 4, with an output shaft 36 of the electric motor 15 connected to the drum 4. In particular, a rotor of the electric motor 15 can be non-rotatably connected to the drum 4.Furthermore, a rotating shaft of the rotor can simultaneously be a rotating shaft of the drum 4. In alternative embodiments, the electric motor 15 can be arranged outside the drum 4 and connected to the drum 4 via power transmission elements such as belts or gears. In other embodiments, the electric motor 15 can be installed inside the drum 4, for example, surrounded by the cylindrical shell of the drum 4, and drive the drum. Preferably, the electric motor 15 is a brushless DC motor 15a. The electric motor 15 applies a defined preload to the drum 4.

[0065] Figure 1 also shows an electrical energy storage device 16, preferably a rechargeable battery 16a, which supplies the measuring device 1 with electrical energy. The energy storage device 16 is not shown in Figures 2 to 19.

[0066] The measuring device 1 also has a measuring arm 13 between the drum 4 and the measuring pin 8, which is articulated to the base body 11 and guides the rollable longitudinal element 5.

[0067] The housing 2 has a height H, a width B, a depth T, a longitudinal direction LR, a transverse direction QR, a vertical direction HR, a front 2a, a back 2b, a top 2c, a bottom 2d and two side parts 2e. The base body 11 has a flat base A in the illustrated examples, which lies in a principal plane HE (see Fig. 6).

[0068] Fig. 5 shows an example of a motor control unit 17 connected to the electric motor 15, configured to operate the electric motor 15 with at least one setpoint torque for extending the retractable longitudinal element 5 into the extended state ZA. The motor control unit 17 can also be configured to operate the electric motor 15 with at least one different setpoint torque for retracting the retractable longitudinal element 5 into the retracted state ZE. Furthermore, the motor control unit 17 can be connected to an input device 18 and configured to operate the electric motor 15 with setpoint torque values ​​adjustable via the input device 18. The input device 18 can be provided in the housing 2 and extend to an outer surface of the housing 2, in the example according to Fig. 5 to the top surface 2c.Alternatively, the input device 18 can include an external, mobile data processing device 19, such as a smartphone, in which case a receiver 20 for the data of the mobile data processing device 19 is provided in the housing 2.

[0069] While Figures 1 to 8 show a measurement in a plane parallel to the main plane HE, Figures 9 to 19 show a spatial measurement.

[0070] Figures 9 to 11 show, by way of example, that the measuring arm 13 is pivotally connected to the base body 11 in a vertical direction HR of the housing 2. For this purpose, a vertical-angle pivot axis 21 can be provided in a plane parallel to the main plane HE, about which the measuring arm 13 pivots. To detect an angle of the measuring arm 13 in the vertical direction HR with respect to the base body 11, the at least one angle sensor 10 can have a vertical-angle sensor 22 connected to the measuring arm 13. Figures 9 to 11 further show, by way of example, that the measuring arm 13 is pivotally connected to the base body 11 in a transverse direction QR of the housing 2. For this purpose, a transverse-angle pivot axis 23 can be provided perpendicular to the main plane HE, about which the measuring arm 13 pivots. In order to detect an angle of the measuring arm 13 in the transverse direction QR with respect to the base body 11, the at least one angle sensor 10 can have a transverse angle sensor 24 connected to the measuring arm 13.

[0071] In particular, Fig. 9 shows that the housing 2 is rotatably mounted on the base body 11 about a housing rotation axis 25. This becomes clearly evident from a comparison of the triangular marking M on the base body 11 in Fig. 2, where the marking M points in the longitudinal direction LR of the housing 2, with the marking M on the base body 11 in Fig. 9, where, due to a rotation of the housing 2, the marking M points in a direction deviating from the longitudinal direction LR of the housing 2. The housing rotation axis 25 is preferably also the transverse angular pivot axis 23 about which the measuring arm 13 pivots.

[0072] Figures 12 to 19 show, by way of example, an auxiliary motor 26 for rotating the housing 2 about the housing axis of rotation 25. Furthermore, an auxiliary sensor 27 connected to the housing 2 is provided by way of example, which is configured to detect a housing rotation angle of the housing 2 with respect to the base body 11 or with respect to the measuring arm 13. Additionally, an auxiliary motor control 28 connected to the auxiliary motor 26, the transverse angle sensor 24, and the auxiliary sensor 27 is provided and configured, depending on the housing rotation angle detected by the auxiliary sensor 27 and, optionally, depending on the angle of the measuring arm 13 in the transverse direction QR detected by the transverse angle sensor 24, to rotate the housing 2 by means of the auxiliary motor 26 in response to a deflection of the measuring arm 13 in the transverse direction QR.Figures 14 to 19 further show, symbolically, the feed device 31 connected to the drum 4, which is designed to adjust the drum 4 along its longitudinal axis 3 during rotation about the drum's longitudinal axis 3 such that the retractable longitudinal element 5 is wound onto the drum 4 in a single position in the retracted state ZE. This allows the drum 4 to be adjusted along its longitudinal axis 3. The feed device 31 can comprise a threaded rod (not shown) attached to the housing 2 and a nut (not shown) attached to the drum 4 that engages in the thread of the threaded rod. For clarity, the feed device 31 is not shown in Figures 1 to 13.

[0073] Figures 10, 11, 13, 15, 18 and 19 also show, by way of example, a deflection roller 30, which is provided in the housing 2 and deflects the coilable longitudinal element 5 from the measuring arm 13 to the drum 4. Particularly preferably, the coilable longitudinal element 5 runs between the deflection roller 30 and the drum 4 along the housing axis of rotation 25.

[0074] Figures 16 to 19 symbolically show a locking device 29 of the measuring device 1, which in a locking state blocks a rotation of the drum 4 and in a release state releases a rotation of the drum 4 and can thus prevent an unintentional unrolling of the rollable longitudinal element 5 from the drum 4 in the locking state.

[0075] Figures 14 and 15 also show a heating device 37 with a heating element 38 designed to emit heat, a temperature sensor 39, and a heating control unit 40. The temperature sensor 39 is connected to the heating element 38 via the heating control unit 40. In the illustrated example, the heating device 37 is arranged in the housing 2. In the example according to Figures 14 and 15, the heating element 38 is provided in addition to the electric motor 15. For example, the heating element 38 can be a resistance heater. In an embodiment not shown, the heating device 37 can also be provided without the temperature sensor 39 and without the heating control unit 40.

[0076] Figures 16 to 19 show the heating device 37, where the electric motor 15 is the heating element 38. The temperature sensor 39 is connected to the electric motor 15 via the motor controller 17. In the illustrated example, the motor controller 17 is therefore also the heating controller 40. Even with the electric motor 15 as the heating element 38, the temperature sensor 39 and the heating controller 40 can be omitted in a simple embodiment not shown.

[0077] Fig. 20 shows an exemplary and simplified block diagram of the measuring device 1, comprising a processing unit 32, in particular a microprocessor 32a, a program and / or data memory 33, a 3-axis accelerometer 34, with which the position of the measuring device 1 with respect to gravity and an undesired, generally jerky displacement of the measuring device 1 can be detected, the motor control 17, the electric motor 15, the height-angle sensor 22, the lateral angle sensor 24, the auxiliary sensor 27, the length sensor 12, the energy storage device 16, the auxiliary motor 26, the locking device 29, the temperature sensor 39, which in one embodiment is connected to the electric motor 15 via the motor control 17, and an alternative heating device 37, shown in dashed lines, which includes a heating element 38 separate from the electric motor 15, a temperature sensor 39, and a Heating control unit 40, and a remote control 35,which allows a user to trigger the acquisition of position data and preferably switch between a point measurement and a line measurement.

[0078] Fig. 21 shows a method for measuring an object 0 with a measuring device 1.

[0079] The method serves to capture at least one point of object 0. The measurement of object 0 can be carried out in a plane, along a line or in all three spatial directions, so that, for example, the position of corners, the course of edges, perimeter profiles, or generally the dimensions and planar or spatial extents of object 0 can be metrologically recorded.

[0080] For this purpose, in step S1, a measuring device 1 is provided by positioning it on a surface with a base body 11 in a fixed position, i.e., as immovable as possible, for the duration of the measurement. For example, the base body 11 has a rubber pad or a correspondingly high weight for this purpose. The base body 11 can also be mounted on a sloping or vertical wall or on a ceiling.

[0081] The positioned measuring device 1 is then switched on in step S2, i.e., supplied with electrical current. Before and immediately after the measuring device 1 is switched on, the retractable longitudinal element 5, with a first end 6 and a second end 7, is in a retracted state ZE, in which the retractable longitudinal element 5 is wound onto the drum 4. The retractable longitudinal element 5 is attached to the drum 4 at its first end 6, guided through the opening 9 in the housing 2, and connected to the measuring pin 8 at its second end 7.

[0082] In step S3, the electric motor 15 of the measuring device 1, which is connected to the drum 4, is also supplied with current. The electric motor 15 generates a preload on the drum 4 by applying a torque to the drum 4 that opposes the extension of the rollable longitudinal element 5 into the extended state ZA.

[0083] In step S4, to perform the measurement, the measuring pin 8 is moved by a user against the force of the preload acting on the drum 4 to at least one position to be measured, thereby tensioning the retractable longitudinal element 5. The retractable longitudinal element 5 then transitions into at least one extended state ZA and is partially unwound from the drum 4 during this transition. The retractable longitudinal element 5 is guided by the measuring arm 13, which is arranged between the drum 4 and the measuring pin 8 and is articulated to the base body 11. Furthermore, the drum 4 is adjusted along its longitudinal axis 3 by the feed device 31 during rotation about the drum's longitudinal axis 3.

[0084] In step S5, a user input triggers the detection of the current position of the measuring pin 8, for which the orientation of the retractable longitudinal element 5 is detected with the at least one angle sensor 10 in relation to the base body 11 supporting the housing 2 and fixed in relation to the object 0, and the longitudinal extent E of the retractable longitudinal element 5 in the extended state ZA in relation to the retracted state ZE is detected with the length sensor 12.

[0085] In an optional sub-step S6, during step S3, the electric motor 15, in particular a brushless DC motor 15a, can be operated via the motor control 17 with at least one setpoint of the torque for extending the rollable longitudinal element 5 into the extended state ZA and in particular with at least one different setpoint of the torque for retracting the rollable longitudinal element 5 into the retracted state ZE.

[0086] In an optional substep S7, located between step S2 and the optional substep S6, a user can enter target torque values ​​into the measuring device 1 via input device 18. The electric motor 15 is then operated in the optional substep S6 using the target torque values ​​set via input device 18. In the optional substep S7, for example, a target torque value can be entered for extending the retractable longitudinal element 5 into the extended state ZA, a different target torque value for detecting the position of the measuring pin 8, and at least one further different target torque value for retracting the retractable longitudinal element 5 into the retracted state ZE.In an optional substep S8, the torque applied to the drum 4 during the detection of the position of the measuring pin 8 can be measured, and in an optional substep S9 following step S5, the object dimensions detected by the angle sensor 10 and the length sensor 12 can be corrected as a function of the measured torque. The optional substep S8 can be performed during step S4 or S5, but in any case, the drum 4 must be subjected to the preload required for the measurement.

[0087] In an optional substep S10, after step S5 or S9, at least one further measurement of object dimensions of the same object 0 can be performed. For this purpose, the electric motor 15 can be operated with a different target torque value for extending the retractable longitudinal element 5 into the extended state ZA compared to the preceding measurement, and preferably with a different target torque value for retracting the retractable longitudinal element 5 into the retracted state ZE compared to the preceding measurement. The object dimensions of the same object 0 can thus be recorded for each of the different target torque values ​​for extending the retractable longitudinal element 5 using the angle sensor 10 and the length sensor 12. Final object dimensions can be calculated from the different recorded object dimensions.

[0088] In an optional sub-step Sil, during step S4, the housing 2 can be rotated by an auxiliary motor 26 to align the rollable longitudinal element 5 or the measuring arm 13 about a housing rotation axis 25 in the transverse direction QR. For this purpose, an auxiliary sensor 27 connected to the housing 2 can detect a housing rotation angle of the housing 2 relative to the base body 11 or relative to the measuring arm 13. In addition, the transverse angle sensor 24 can detect an angle of the measuring arm 13 in a transverse direction QR of the housing 2 relative to the base body 11.Furthermore, an auxiliary motor control 28, connected to the auxiliary motor 26, the transverse angle sensor 24, and the auxiliary sensor 27, can rotate the housing 2 via the electric auxiliary motor 26 until the housing rotation angle detected by the auxiliary sensor 27 matches the angle of the measuring arm 13 detected by the transverse angle sensor 24, provided the auxiliary sensor 27 detects the housing rotation angle of the housing 2 relative to the base body 11. Alternatively, the auxiliary motor control 28 can rotate the housing 2 via the electric auxiliary motor 26 until the housing rotation angle detected by the auxiliary sensor 27 is zero, provided the auxiliary sensor 27 detects the housing rotation angle of the housing 2 relative to the measuring arm 13.

[0089] In step S12, after step S5, the retractable longitudinal element 5 is retracted back into the housing 2, for which the user, for example, reduces his force on the measuring pin 8.

[0090] In a sub-step S13, during step 12, the drum 4 is adjusted along the drum longitudinal axis 3 by a feed device 31 during rotation about the drum longitudinal axis 3 such that the rollable longitudinal element 5 is rolled onto the drum 4 in a single position when transitioning to the retracted state ZE.

[0091] In step S14, the recorded and, if necessary, corrected object dimensions are saved or output to the user.

[0092] In an optional substep S15, during step S2, preferably after deactivating the locking device 29 but before the first measurement or between measurements, the heating device 37 can be activated and the drum 4 can be heated by a heating element 38 of the heating device 37.

[0093] In an optional sub-step S16, during step S3, preferably after deactivating the locking device 29 but before the first measurement or between measurements, the drum 4 can be heated by the electric motor 15, which is supplied with electrical current. For this purpose, the torque of the electric motor 15, and thus the heat output of the electric motor 15, can be adjusted, and in particular the temperature can be regulated to a predetermined operating temperature.

[0094] It should be noted that steps S1 to S14 do not necessarily have to be carried out in the order given and shown in Fig. 21.

Claims

Patent claims:

1. Measuring device (1) for measuring an object (0), comprising a housing (2) in which a drum (4) rotatably mounted about a drum longitudinal axis (3) is received, and comprising a rollable longitudinal element (5) having a first end (6) and a second end (7), which in a retracted state (ZE) is wound onto the drum (4) and in at least one extended state (ZA) is partially unwound from the drum (4), and which is attached to the drum (4) at its first end (6), is guided through an opening (9) in the housing (2) and is connected at its second end (7) to a measuring pin (8) which is intended for movement by a user.wherein at least one angle sensor (10) is provided for detecting the orientation of the retractable longitudinal element (5) with respect to a base body (11) supporting the housing (2) and fixed with respect to the object (0), and a length sensor (12) is provided for detecting the longitudinal extent (E) of the retractable longitudinal element (5) in the extended state (ZA) with respect to the retracted state (ZE), wherein a measuring arm (13) is provided between the drum (4) and the measuring pin (8) and guides the retractable longitudinal element (5), and the drum (4) is connected to a pretensioning device (14), wherein the pretensioning device (14) has an electric motor (15) connected to the drum (4), which is arranged to apply a torque to the drum ( 4 ) that opposes the pulling out of the rollable longitudinal element ( 5 ) into the extended state ( ZA ),characterized in that the drum (4) is arranged adjustably along the drum longitudinal axis (3) and a feed device (31) connected to the drum (4) is formed to adjust the drum (4) during rotation about the drum longitudinal axis (3) along the drum longitudinal axis (3) such that the rollable longitudinal element (5) is rolled up in a single position on the drum (4) in the retracted state (ZE).

2. Measuring device ( 1 ) according to claim 1 , wherein 38 characterized in that a motor control (17) connected to the electric motor (15), in particular a brushless DC motor (15a), is designed to operate the electric motor (15) with at least one setpoint of torque for extending the rollable longitudinal element (5) into the extended state (ZA) and in particular with at least one different setpoint of torque for retracting the rollable longitudinal element (5) into the retracted state (ZE).

3. Measuring device ( 1 ) according to claim 2, characterized in that the motor control ( 17 ) is connected to an input device ( 18 ) and is configured to operate the electric motor ( 15) with target values ​​of torque adjustable via the input device ( 18 ).

4. Measuring device ( 1 ) according to claim 3, characterized in that the input device ( 18 ) is designed for inputting at least two setpoint values ​​of the torque for extending the rollable longitudinal element (5) into the extended state (ZA) and preferably for inputting at least two different setpoint values ​​of the torque for retracting the rollable longitudinal element (5) into the retracted state (ZE).

5. Measuring device ( 1 ) according to one of claims 1 to 4, characterized in that the length sensor ( 12 ) is connected to the drum (4 ) and is designed to detect a rotational position of the drum (4 ) about the drum longitudinal axis (3 ).

6. Measuring device (1) according to one of claims 1 to 5, characterized in that the measuring arm (13) is pivotally connected to the base body (11) in a vertical direction (HR) of the housing (2) and the at least one angle sensor (10) has a height-angle sensor (22) connected to the measuring arm (13), which is configured to detect an angle of the measuring arm (13) in the vertical direction (HR) with respect to the base body (11). Measuring device (1) according to one of claims 1 to 6, characterized in that the measuring arm (13) is pivotally connected to the base body (11) in a transverse direction (QR) of the housing (2) and the at least one angle sensor (10) has a transverse angle sensor (24) connected to the measuring arm (13), which is configured to detect an angle of the measuring arm (13) in the transverse direction (QR) with respect to the base body (11).

8. Measuring device ( 1 ) according to one of claims 1 to 7 , characterized in that the housing ( 2 ) is rotatably mounted on the base body ( 11 ) about a housing rotation axis ( 25 ).

9. Measuring device (1) according to claim 8, characterized in that an auxiliary motor (26) is provided for rotating the housing (2) about the housing rotation axis (25), an auxiliary sensor (27) connected to the housing (2) is formed to detect a housing rotation angle of the housing (2) with respect to the base body (11) or with respect to the measuring arm (13), and an auxiliary motor control (28) connected to the auxiliary motor (26), the transverse angle sensor (24) and the auxiliary sensor (27) is formed, rotating the housing (2) via the electric auxiliary motor (26) until the housing rotation angle detected by the auxiliary sensor (27) matches the angle of the measuring arm detected by the transverse angle sensor (24). 13) to rotate when the auxiliary sensor (27) is configured to detect the housing rotation angle of the housing (2) in relation to the base body (11), or the auxiliary motor control (28) is configuredto rotate the housing (2) via the electric auxiliary motor (26) until the housing rotation angle detected by the auxiliary sensor (27) is zero, if the auxiliary sensor (27) is configured to detect the housing rotation angle of the housing (2) with respect to the measuring arm (13).

10. Measuring device (1) according to claim 8, characterized in that a deflecting roller (30) is provided in the housing (2) to deflect the rollable longitudinal element (5) from the measuring arm (13) to the drum (4), and in particular the rollable longitudinal element (5) runs between the deflecting roller (30) and the drum (4) along the housing rotation axis (25).

11. Measuring device ( 1 ) according to one of claims 1 to 10, characterized in that a locking device (29) is provided which in a locking state blocks a rotation of the drum (4 ) and in a release state releases a rotation of the drum (4 ).

12. Measuring device ( 1 ) according to one of claims 1 to 11, characterized in that the rollable longitudinal element (5) is a rope, preferably a metal rope consisting of a plurality of metal strands, with a preferably substantially circular cross-section .

13. Method for measuring an object (0) with a measuring device (1) which has a drum (4) rotatably mounted about a drum longitudinal axis (3) in a housing (2) and has a rollable longitudinal element (5) having a first end (6) and a second end (7), which is wound onto the drum (4) in a retracted state (ZE) and is partially unwound from the drum (4) during the transition to at least one extended state (ZA), and which is attached to the drum (4) at its first end (6), is guided through an opening (9) in the housing (2) and is connected at its second end (7) to a measuring pin (8), which is moved by a user against the force of a preload acting on the drum (4) to at least one position to be measured, thereby tensioning the rollable longitudinal element (5).wherein at least one angle sensor (10) detects the orientation of the retractable longitudinal element (5) with respect to a base body (11) supporting the housing (2) and fixed with respect to the object (0), and wherein a length sensor (12) detects the longitudinal extent (E) of the retractable longitudinal element (5) in the extended state (ZA) with respect to the retracted state (ZE), wherein the retractable longitudinal element (5) is guided by a measuring arm (13) arranged between the drum (4) and the measuring pin (8) and pivotally connected to the base body (11), wherein the preload is generated by an electric motor (15) connected to the drum (4), which applies a torque to the drum (4) that opposes the extension of the retractable longitudinal element (5) into the extended state (ZA), characterized in thatthat the drum (4 ) is adjusted along the drum's longitudinal axis (3) by a feed device (31 ) during rotation about the drum's longitudinal axis (3) such that the rollable longitudinal element (5) is rolled onto the drum (4 ) in a single position when transitioning to the retracted state (ZE).

14. Method according to claim 13, characterized in that the electric motor ( 15) is operated with at least one setpoint of torque for extending the rollable longitudinal element (5) into the extended state (ZA) and in particular with at least one different setpoint of torque for retracting the rollable longitudinal element (5) into the retracted state (ZE), in particular with setpoints of torque adjustable via an input device ( 18 ).

15. Method according to claim 13 or 14, characterized in that the torque of the drum (4 ) is measured and the object dimensions detected by the angle sensor ( 10) and the length sensor ( 12 ) are corrected with the measured value of the torque.

16. Method according to claim 14, characterized in that, for several measurements of object dimensions of the same object (0), the electric motor (15) is operated with at least two different setpoints of torque for extending the retractable longitudinal element (5) into the extended state (ZA) and preferably with at least two different setpoints of torque for retracting the retractable longitudinal element (5) into the retracted state (ZE), the object dimensions of the same object (0) are detected with the angle sensor (10) and the length sensor (12) for each setpoint of torque for extending the retractable longitudinal element (5), and final object dimensions are calculated from the different detected object dimensions.42 17. A method according to any one of claims 13 to 16, characterized in that the housing (2) is rotated about a housing rotation axis (25) by an auxiliary motor (26), wherein an auxiliary sensor (27) connected to the housing (2) detects a housing rotation angle of the housing (2) with respect to the base body (11) or with respect to the measuring arm (13), a transverse angle sensor (24) detects an angle of the measuring arm (13) in a transverse direction (QR) of the housing (2) with respect to the base body (11), and an auxiliary motor controller (28) connected to the auxiliary motor (26), the transverse angle sensor (24) and the auxiliary sensor (27) rotates the housing (2) via the electric auxiliary motor (26) until the Adjusting the housing rotation angle detected by the auxiliary sensor (27) to the angle of the measuring arm (13) detected by the transverse angle sensor (24) when the auxiliary sensor (27) detects the housing rotation angle of the housing (2) in relation to the base body (11),or the auxiliary motor control (28) rotates the housing (2) via the electric auxiliary motor (26) until the housing rotation angle detected by the auxiliary sensor (27) is zero, when the auxiliary sensor (27) detects the housing rotation angle of the housing (2) with respect to the measuring arm (13).

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