Measuring device for determining stiffness values ​​of surfaces in the interior of a vehicle

Abstract

Measuring device (10) for determining stiffness values ​​of surfaces (112) in the interior (110) of a vehicle (100), comprising at least one bearing module (20) for arrangement on the floor (200) next to the vehicle (100), an arm module (30) for fastening to the bearing module (20) so that it can move in at least one direction, and a measuring head (40) for fastening to the arm module (30) so that it can move in at least one direction, wherein the measuring head (40) has a measuring sensor (44) and a measuring base (42), and the measuring sensor (44) is mounted relative to the measuring base (42) for carrying out a measuring movement.

Description

The present application relates to a measuring device for determining rigidity values of surfaces in the interior of a vehicle and to a method for determining rigidity values of surfaces in the interior of a vehicle.It is known that different surfaces are used in the interior of vehicles. For example, the headliner of a vehicle is often provided with a fabric covering. Lateral trim parts on the inner trim of the doors can have leather elements or likewise fabric elements. Plastic covers, such as, for example, on the armrest in the center console or on the interior lining of the doors, can also be provided. Depending on the type and location of the surface, different stiffness values may be desired or required. Thus, for example, arm coverings must be provided with necessarily higher rigidity than is the case with purely decorative surfaces, such as the roof lining. In known vehicles, these rigidity values are already checked in prototypes or in pre-series models. This is not a series quality assurance, but a quality determination, in particular in a quantitative manner, on the prototypes or on the pre-series model. In order to determine the rigidity values of the individual surfaces in the interior, rigidity measurement sensors are known for this purpose, which are arranged at a wide variety of measurement positions by a person on the prototype or on the pre-series model. This has the result that this person has to move to each measurement position of each surface in a manual manner and carries out the measurement there.This includes a relatively long execution time in order to reach all measurement positions of all surfaces in the interior of the vehicle. Another disadvantage of the known way of carrying out the measurement is that there is no defined abutment force for the measurement sensor. In particular, there is a lack of a defined resistance force for carrying out a corresponding measurement movement, so that the determined stiffness values can be subject to manual fluctuations. This may possibly lead to quantitative misdetermination of the respective stiffness value.Prior art document relating to the field of the present invention is known from DE 20 2007 018 383 U1 and DD 2 83 209 A5.It is an object of the present invention to at least partially eliminate the disadvantages described above. In particular, it is the object of the present invention to ensure the determination of the stiffness in a defined manner for as many measurement points as possible in a cost-effective and simple manner.The above object is achieved by a measuring device having the features of claim 1 and a method having the features of claim 10. Features and details which are described in connection with the measuring device according to the invention naturally also apply in connection with the method according to the invention and vice versa, so that with regard to the disclosure reference is or can always be made reciprocally to the individual aspects of the invention.A measuring device according to the invention is used for determining rigidity values of surfaces in the interior of a vehicle. For this purpose, the measuring device according to the invention has at least one bearing module for arrangement on the floor next to the vehicle, an arm module for fastening to the bearing module which can be moved at least in one direction, and a measuring head for fastening to the arm module which can be moved at least in one direction. The measuring head has a measurement sensor and a measurement base. The measuring sensor is mounted relative to the measuring base for carrying out a measuring movement.In contrast to known solutions for determining the stiffness values, a measuring device is proposed according to the invention, which can be mounted outside the vehicle. The bearing module can thus be arranged on the floor next to the vehicle and is in particular mounted displaceably on the floor. Thus, the measuring device can be moved by means of the storage module to a corresponding opening of the vehicle, for example the side doors or the trunk. An arm module is fastened or can be fastened to the bearing module, which is mounted movably on the bearing module. Thus, after the movement of the bearing module into a basic position, a finer movement of the arm module into the interior of the vehicle through the side door or into the trunk is possible. Finally, a fine positioning of the measuring head can now take place at the preferably other end of the arm module. This measuring head is now positioned at the respective measurement position in contact of the measurement sensor with the surface. The measurement movement can then preferably be carried out automatically.A measuring device according to the invention is used in particular in prototypes or pre-series vehicles in the development of the vehicles. The vehicle can be positioned in a corresponding hall and the determination of the rigidity values of the surfaces in the interior can be carried out in a short and above all defined manner using the measuring device according to the invention. It should be pointed out here that the movable fastening of the arm module or of the measuring head is preferably designed for a manual movement. This means that the positioning of the measuring head in the respective measurement position is carried out manually by a worker. Subsequently, the respective measuring movement is carried out manually or preferably automatically by the measuring head by a drive device, which is driven electrically, for example.According to the invention, the determination can now be carried out in a short time and above all in a defined manner. In particular, it becomes possible in this way to provide the respective support of the measuring force in a defined manner. The measurement base thus remains substantially immovably mounted during the measurement movement via the arm module and the bearing module on the ground next to the vehicle. This has the result that, in contrast to mobile measuring devices, a stationary and thus unambiguously defined state is now present here for carrying out the measuring movement.A measuring device according to the invention thus permits a clearly defined and at the same time more rapid execution of the individual determination steps for a wide variety of measurement positions in the case of rigidity values of surfaces.Within the meaning of the present invention, an interior is to be understood as any inwardly directed region of the vehicle. In particular, this is the passenger compartment and the trunk compartment of the vehicle.The surfaces are, in particular, vision surfaces and / or contact surfaces for the purposes of the present invention, so that haptic values for the haptic quality can be determined by determining stiffness values for these surfaces.The attachment between arm module and bearing module or between measuring head and arm module is reversible or irreversible. Depending on the actual geometric extent of the respective module, the reversible or the irreversible manner can be advantageous. As described later, locking devices can be provided in order to cancel the mobility of the respective bearing in the case of measurement.A measuring device according to the invention is used, for example, when the interior is to be measured with respect to all surfaces in a prototype. For this purpose, the measuring device with the storage module is moved into a basic position. This can also be referred to as a coarse setting of the measuring device. The arm module and thus also the measuring head are then moved manually into the interior space into the respective measurement position. This can also be understood as fine adjustment. After this fine adjustment, the measurement movement is preferably carried out in an automated manner. Subsequently, a changed fine adjustment can be carried out via the arm module and the measuring head in order to achieve a positioning at the next measurement position. Only when leaving the interior and, for example, when passing into the trunk, a basic positioning or rough positioning must again be carried out by moving the bearing module. It is apparent from this that it is possible to reach the individual measurement positions very quickly and nevertheless in a defined manner with the measuring device according to the invention.It can be advantageous if, in a measuring device according to the invention, the fastening of the arm module to the bearing module and / or the fastening of the measuring head to the arm module have at least one arresting device for arresting the freedom of movement. This means that after the manual movement of the measuring head into the desired measurement position, locking is carried out. These can be, for example, clamping devices or other latching devices which ensure that during the measurement movement there is no longer any freedom of movement in a relative manner between the measuring head, arm module and bearing module. This has the result that the increasing measuring force can be supported on the ground next to the vehicle during the determination of the stiffness via the measuring head, arm module and bearing module. The locking devices are preferably manual, in particular manual-mechanical locking devices, which can perform the locking in a simple, quick and above all reversible manner.It is likewise advantageous if, in a measuring device according to the invention, two bearing modules are provided for arrangement on two different sides of the vehicle. The arm module is designed as a cross member which can be fastened to both bearing modules. The two bearing modules thus form pillar-like structures on the left and right of the vehicle. The arm module is pushed through the two open side doors of the vehicle and then fastened to the two pillar-like storage modules. The fastening is preferably effected in the form of a movability upwards and downwards, so that the arm module in the form of the cross member is movable upwards and downwards. At the same time, the fastening interfaces on the two storage modules are preferably designed as rotary tables, as will be explained in the following.It can be further advantageous if, in a measuring device according to the invention according to the preceding paragraph, the arm module can be fastened to the two bearing modules in each case rotatably and translationally displaceably. The arm module in the form of the cross member can thus be displaced both upwards and downwards if it already extends through the interior of the vehicle through the two open side doors. Through a rotation capability, which can be provided, for example, in more than 360° by a rotary plate at the fastening interface on the bearing modules, the desired free positionability of the measuring head can take place. Preferably, there can also be an additional movability of the measuring head, as explained below.Thus, in this embodiment of the present invention, it can be advantageous if the measurement base is designed as a leg, in particular as an L leg, on which the measurement sensor is mounted for carrying out the measurement movement. Thus, the measurement base can be displaced, for example, in a groove still relative to the arm module. The measuring sensor itself is now mounted movably on the leg, so that the measuring movement can be carried out by this relative movement possibility. The measuring movement itself can be carried out either manually or automatically, for example in the form of an electric drive device.It is furthermore advantageous if, in a measuring device according to the invention, the bearing module is designed as a counterweight for the arm module. This means that in particular a single bearing module is sufficient to provide the advantages of the measuring device according to the invention. In particular, the bearing module has a weight of more than about 100 kg. Since only relatively low feed forces are necessary for the measuring sensor in comparison with this high counterweight, a clean support of the measuring force during the measuring movement can be provided in this way. This makes it possible, despite the cost-effective and space-saving one-sided mounting of the position module, to enable the advantages according to the invention and in particular the defined mounting for supporting the measurement force.It is furthermore advantageous if, in a measuring device according to the invention according to the preceding paragraph, the arm module is fastened to the bearing module such that it can be moved translationally in at least two directions.The arm module in this embodiment can preferably be movable into the vehicle as a height adjustment and as a delivery. This again involves the external rough adjustment and, during the movement into the interior of the vehicle, the fine adjustment into this interior. Movability of the bearing module itself can likewise again be provided on rollers or, for example, on an air cushion. Thus, the entire measuring device can be slid around the vehicle via the storage module in order to be able to carry out the measurement both for the interior of the vehicle within the passenger compartment and within the trunk compartment.A further advantage can be achieved if, in a measuring device according to the invention of the two preceding paragraphs, the measuring base is fastened to the arm module in a rotationally movable manner and preferably in a translatory manner. The rotational mobility is preferably 360° or more. Of course, pivot options for the arm module or the measurement base are also conceivable. This rotational and / or preferably also translational mounting is in particular the possibility of carrying out the manual fine adjustment, already described several times, during the positioning of the measurement sensor in the interior of the vehicle.It is furthermore advantageous if, in a measuring device according to the invention, the measuring head has a drive device, in particular an electromotive drive device, for carrying out the measuring movement. This makes it possible to provide a defined measurement movement with respect to the movement implementation and the movement speed or the movement force. In particular, for example, the measurement logic for controlling or regulating or evaluating the measurement movement can also be present or arranged in the measurement head. The arrangement of a drive device, in particular an electric motor, makes it possible to always carry out the measurement movement in a reproducible manner in the same and defined manner. This leads to a high comparison of the determined stiffness values and thus to a high accuracy in the determination of these stiffness values. The electromotive drive unit is in particular designed to be regulable and has a constant adjustable feed speed over the entire force range and the entire travel range of the measurement.The present invention also relates to a method for determining rigidity values of surfaces in the interior of a vehicle. In particular, this method is carried out with a measuring device according to the invention. The method according to the invention comprises the following steps:arranging a sensor in a measurement position in contact with a surface in the interior of the vehicle,performing a measurement movement with the measurement sensor with elastic deformation of the surface,determining the force-displacement characteristic curve for the measurement movement,evaluating the force-displacement characteristic curve in a range between a first force value and a second force value for the stiffness of the surface,comparing the evaluated stiffness with at least one predefined value.By using a measuring device according to the invention, a method according to the invention brings with it the same advantages as have been explained in detail with reference to a measuring device according to the invention. According to the invention, in this method, after the determination of the force-displacement characteristic curve, only a part of this characteristic curve is made available for the rigidity determination. Thus, the stiffness of the surface is determined between two force values, in particular in the form of an evaluation for the gradient of the force-displacement characteristic curve between these two force values. This gradient can be determined directly if the force-displacement characteristic curve is a straight line or substantially a straight line. Naturally, however, compensation straight line or tangent methods can also be used in order to be able to determine a gradient between the two force values. By comparing the evaluated stiffness with at least one predefined value, a direct quality evaluation is also possible. Thus, the predefined value can provide, for example, an individual limit value or a limit range which correlates with permissible tolerance ranges. The display of such a result in comparison with the respective predefined value can, for example, give the worker an indication of the current quality situation, visually easily perceptible, via color systems. If the ascertained stiffness value lies within the permissible tolerance range, this can be displayed, for example, with a green color. If it is located at the edge of the tolerance range, this can be represented with a yellow color. If the determined and evaluated stiffness lies outside the predefined value in the form of a tolerance range, a red color can indicate this, and provide the worker with the corresponding information. The measurement position in contact with the surface is to be understood in particular as a defined distance (gap or precise contact with preload equal to zero) from the measurement point (surface) or a defined preload.Further advantages, features and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can be essential to the invention individually or in any combination. They show schematically: FIG. 1 shows a first embodiment of a measuring device according to the invention, FIG. 2 shows the embodiment of FIG. 1 in use in a vehicle, FIG. 3 shows a further embodiment of a measuring device according to the invention, FIG. 4 shows the embodiment of FIG. 3 when used in the interior of a vehicle, and FIG. 5 shows a force-displacement characteristic curve generated by a method according to the invention.FIGS. 1 and 2 show a first embodiment of a measuring device 10 according to the invention. It can be clearly seen in FIG. 1 that an arm module 30 is designed here as a removable cross member. This arm module 30 in the form of the cross member can be fastened to two bearing modules 20 which are designed in the manner of columns. FIG. 1 shows this arm module 30 both in the separated and fastened positions.The two pillar-like storage modules 20 are arranged on the floor 200 via bearings 22. This allows displacement forwards and backwards, as indicated by the lateral double arrow. The arm module 30 in the form of the cross-member is likewise movable, namely is fastened to the two bearing modules such that it can be displaced upwards and downwards. At the same time, a rotation capability of the arm module 30 relative to the bearing modules 20 is provided via a rotary plate. A last freedom of movement clearance is provided for the measuring head 40, which can be moved translationally, for example in a groove, from left to right.According to the invention, a vehicle 100 can now be arranged between the two pillar-like storage modules 20, as shown in FIG. 2. Then, the arm module 30 is pushed through the interior 110 of the vehicle 100 and fastened to the two pillar-like storage modules 20. Now, a rough adjustment can be made by moving the arm module 30 up and down. By rotating the arm module 30 or displacing the measuring head 40, a fine adjustment for positioning the measuring head 40 in the respective desired measurement position can be carried out. The measuring head 40 itself has a measuring base 42 and a measuring sensor 44 via an L-leg. In the respective measurement position, the tip of the sensing probe 44 is in contact with the corresponding surface 112 of the vehicle 100. By means of a drive device 46, which can be formed here by electric motor, the measuring movement is adjusted and carried out in order to determine the rigidity value of this surface 112. Subsequently, by varying via the fine adjustment and / or the rough adjustment, a positioning of the measuring head 40 at the next measurement position can be effected.FIGS. 3 and 4 show an alternative embodiment of a measuring device 10 according to the invention, which is used in the same manner as has been explained with reference to FIGS. 1 and 2. However, this is a column-like bearing module 20, which is designed as a counterweight for the arm module 30 and the measuring head 40. Thus, it is sufficient if the arm module 30 is provided as a cantilever arm extending to the right. Here too, the corresponding movement options for the rough adjustment and the fine adjustment are again shown by double arrows or a rotation arrow. The bearing 22 of the bearing module 20 is provided here in the form of an air cushion in order to also allow a movability of this high counterweight of several 100 kg.FIG. 4 again shows the situation used for the measuring device 10, which carries out the same steps for coarse adjustment, fine adjustment and measuring movement for carrying out the method according to the invention as have been explained with reference to FIGS. 1 and 2.It is common to the two embodiments of FIGS. 1 to 4 that a plurality of locking devices 50 are provided in order to be able to provide locking of the respective freedom of movement. In particular, all movement options are provided with locking devices 50 in order to provide a respective locking mechanism for carrying out the measurement movement itself. This ensures that a defined and clean support of the measuring force when performing the measuring movement is not impaired by a still remaining freedom of movement.FIG. 5 shows a possibility of a force-displacement characteristic curve 300 generated by a method according to the invention. Between two force values 310 and 320, the evaluation for the stiffness is carried out. This can be done by a compensation straight line, a tangent line or an approximation straight line, which is evaluated with regard to its gradient. In this case, the two force values 310 and 320 can be predefined values or variably adjustable values.The above embodiment with respect to the exemplary embodiments describes the present invention exclusively within the scope of examples. Of course, individual features of the embodiments can be freely combined with one another, insofar as technically expedient, without departing from the scope of the present invention.List of reference characters10 Measuring device 20 Bearing module 22 Bearing of bearing module 30 Arm module 40 Measuring head 42 Measuring base 44 Measuring sensor 46 Drive device 50 Locking device 100 Vehicle 110 Interior 112 Surface 200 Floor 300 Force-displacement characteristic curve 310 First force value 320 Second force value

Claims

Measuring device (10) for determining rigidity values of surfaces (112) in the interior (110) of a vehicle (100), having at least one bearing module (20) for arrangement on the floor (200) next to the vehicle (100), an arm module (30) for fastening to the bearing module (20) such that it can be moved at least in one direction, and a measuring head (40) for fastening to the arm module (30) such that it can be moved at least in one direction, wherein the measuring head (40) has a measurement sensor (44) and a measurement base (42) and the measurement sensor (44) is mounted relative to the measurement base (42) for carrying out a measurement movement.Measuring device (10) according to claim 1, characterised in that the fastening of the arm module (30) to the bearing module (20) and / or the fastening of the measuring head (40) to the arm module (30) have at least one arresting device (50) for arresting the freedom of movement.Measuring device (10) according to one of the preceding claims, characterized in that two bearing modules (20) are provided for arrangement on two different sides of the vehicle (100), wherein the arm module (30) is designed as a cross member which can be fastened to both bearing modules (20).Measuring device (10) according to claim 3, characterised in that the arm module (30) can be fastened to the two bearing modules (20) in each case rotatably and translationally displaceably.Measuring device (10) according to either of Claims 3 and 4, characterized in that the measuring base (42) is designed as a limb, in particular as an L limb, on which the measurement sensor (44) is mounted for carrying out the measuring movement.Measuring device (10) according to one of the preceding claims, characterized in that the bearing module (20) is designed as a counterweight for the arm module (30).Measuring device (10) according to claim 6, characterised in that the arm module (30) is fastened to the bearing module (20) so as to be movable in translation in at least two directions.Measuring device (10) according to one of claims 6 or 7, characterised in that the measuring base (42) is fastened to the arm module (30) in a rotationally movable manner and preferably in a translatory manner.Measuring device (10) according to one of the preceding claims, characterized in that the measuring head (40) has a drive device (46), in particular an electromotive drive device (46), for carrying out the measuring movement.Method for determining rigidity values of surfaces (112) in the interior (110) of a vehicle (100), having a measuring device (10) having the features of one of Claims 1 to 9, having the following steps: - arranging a measurement sensor (44) in a measuring position in contact with a surface (112) in the interior (110) of the vehicle (100), - carrying out a measuring movement with the measurement sensor (44) with elastic deformation of the surface (112), - determining the force-path characteristic curve (300) for the measuring movement, - evaluating the force-path characteristic curve (300) in a range between a first force value (310) and a second force value (320) for the rigidity of the surface (112), - comparing the evaluated rigidity with at least one predefined value.

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