Open roof assembly for use in a vehicle and method of operating the same

Abstract

An open roof assembly for use in a roof of a vehicle includes a movably arranged closure member for closing an opening in the roof and a squeeze detection module for detecting squeeze of an object between the closure member and an edge of the opening. The squeeze detection module is operatively coupled to receive an input signal and is configured to detect the squeeze based on the input signal and a threshold value. The squeeze detection module is configured to dynamically determine the threshold value based on the input signal.

Description

Technical Field

[0001] The present invention relates to an open roof assembly for use in the roof of a vehicle. Background Art

[0002] An open roof assembly for use in a roof of a vehicle is known. In particular, a known open roof assembly comprises a movably arranged closing member for closing an opening in the roof. For example, the closing member may be a glass panel that can be tilted or slid open. Thus, in the closed position, daylight can enter the interior of the vehicle through the glass panel in the roof, whereas in the tilted or at least partially slid open position, air flow between the interior and the exterior is allowed.

[0003] In known open roof assemblies, a squeeze detection module is provided. The squeeze detection module is configured to detect the squeeze of an object between a closure member and an edge of an opening in the roof. Such a squeeze detection module may be provided for safety reasons or to protect the open roof assembly from damage.

[0004] In particular, for safety reasons, legal requirements may apply. Although such legal requirements may vary according to jurisdiction, there is generally an applicable maximum squeeze force of 100 N. Therefore, the squeeze detection module is preferably designed and constructed to detect squeezes and stop the movement of the closure member before the object is squeezed with a force exceeding 100 N. Although a maximum force of 100 N is a common requirement, how the maximum force is determined (e.g., the type of object used) may vary significantly. For example, in some jurisdictions, a hard object will be used, while in other jurisdictions, a soft object will be used to determine whether the legal requirements are met.

[0005] The squeeze detection module is operatively connected to receive an input signal and is configured to detect the squeeze based on the input signal and a threshold value. For example, when a squeeze occurs, the input signal may have an increasing amplitude. Thus, if the amplitude exceeds the threshold value, a squeeze is detected. In another known embodiment, the rate of increase or decrease of the input signal over time can be compared to the threshold value so that a squeeze is detected when the signal increases faster than the threshold value.

[0006] The above-mentioned known methods for detecting the occurrence of squeezes are able to detect squeezes, but are also sensitive to deviations, due to which the squeeze detection module may falsely detect the occurrence of squeezes when squeezes do not actually occur. Therefore, in practice, either the threshold is set relatively low to ensure that every squeeze is detected, resulting in the squeeze detection module often falsely detecting the occurrence of squeezes, or the threshold is set relatively high to prevent such false detections, but resulting in an increased probability of not detecting actual squeezes, which may bring safety hazards. Generally, a trade-off between the two thresholds is selected so that the minimum false squeeze detection occurs under sufficiently safe conditions.

[0007] However, due to manufacturing tolerances, local legal requirements, and varying operating conditions (e.g., due to weather, road conditions, wear over time, etc.), it may be difficult to set an appropriate threshold and additional manufacturing operations may be required to set a dedicated threshold for each open roof assembly, which may need to be adjusted over time due to wear. Summary of the invention

[0008] An object of the present invention is to provide a safe and reliable squeeze detection system and method that can adapt to different environments.

[0009] In a first aspect, the object is achieved in an open roof assembly for use in a roof of a vehicle according to the present application. The open roof assembly comprises a movably arranged closing member for closing an opening in the roof and a squeeze detection module for detecting a squeeze of an object between the closing member and an edge of the opening. The squeeze detection module is operatively connected to receive an input signal. Further, the squeeze detection module is configured to detect the squeeze based on the input signal and a threshold value. The squeeze detection module is further configured to dynamically determine the threshold value based on the input signal.

[0010] According to the present invention, the threshold value is dynamically adjusted based on the input signal so that the threshold value is adapted to the actual situation. The threshold value is adjusted according to the input signal and in particular how the input signal develops over time. If the input signal increases over time, the threshold value may increase with the input signal or may decrease, depending on the environment. In the case where the input signal changes rapidly, the threshold value may change a little bit before the input signal exceeds the threshold value and the squeeze is detected, while for a slowly changing input signal, the threshold value may slowly decrease and eventually the input signal may exceed the threshold value so that the squeeze is detected. Moreover, the squeeze detection module is not only able to compensate for changes caused by the environment, so the squeeze detection module according to the present invention is also very suitable for detecting squeezing of soft objects or hard objects.

[0011] In an embodiment of the open roof assembly according to the present invention, the squeeze detection module is configured to perform the steps of: receiving the input signal; determining the threshold value based on the input signal; detecting the squeeze by comparing the input signal with the threshold value determined in step b; and repeating the previous steps. In this embodiment, the threshold value is repeatedly determined based on the input signal. After determining the threshold value, the threshold value and the input signal are compared to determine whether a squeeze occurs. If the comparison does not indicate that a squeeze occurs, the steps are repeated.

[0012] It should be noted that the step of determining the threshold value may not be performed in every cycle of the step, depending on, for example, the desired accuracy and time sensitivity. For example, if the input signal comprises samples at a high sampling rate, it may be sufficient to determine the threshold value at a lower rate, for example once every 10 input signal samples. This may be sufficient for squeeze detection, while it reduces the requirements on resources and thus improves cost-effectiveness.

[0013] In an embodiment of the open roof assembly, the squeeze detection module is configured to normalize the input signal prior to determining the threshold value, thereby providing a normalized input signal. As used herein, normalization is intended to remove input offsets from the input signal so as to enable squeeze detection based on deviations and variations in the input signal. These deviations and variations are retained in the normalized input signal.

[0014] In a particular embodiment, a median value of a selected portion of the input signal is derived and subtracted from the input signal to provide the normalized input signal.Thus, the median value of a portion of the input signal is considered to represent the input offset.

[0015] In another embodiment, the rate of change of the normalized input signal over time is limited by the squeeze detection module. Assuming that the acceptable change of the input offset is a slow change, the rate of change of the input offset is limited so that faster changes remain reflected in the normalized input signal as a possible indication of squeeze.

[0016] In one embodiment, the step of determining the threshold value includes determining an input compensation value based on the input signal and combining a threshold deviation value and the input compensation value. In a specific embodiment, the step of determining the input compensation value includes determining a median of one of the input signal and a normalized input signal. The threshold deviation value is adjusted based on the input signal by determining the input compensation value based on the input signal. Determining the input compensation value may include determining a median of the input signal, wherein a rate of change over time may be limited by the squeeze detection module, similar to the above-described embodiment for determining the normalized input signal.

[0017] In one embodiment, the step of determining the threshold value comprises deriving an input saturation value from the input signal and combining the threshold deviation value with the input saturation value. The saturation value may be used to take into account specific characteristics and features of the input signal, for example due to characteristics and features of a sensor supplying the input signal (such as possible saturation of the sensor), wherein the saturation value is selected from a table or determined based on the input signal.

[0018] In one embodiment, the rate of change of the threshold over time is limited by the squeeze detection module. Similar to the above-described embodiment of the normalized input signal, abrupt changes in the threshold based on changes in the input signal are not expected and are therefore assumed to be indicative of a squeeze. Thus, the rate of change can be limited to prevent a squeeze from potentially not being detected due to the threshold being overly adjusted.

[0019] In a particular embodiment, the open roof assembly is provided with a pressure sensing device configured to output a sensing signal, wherein the pressure sensing device is arranged and configured to change the sensing signal when an object is squeezed, and wherein the input signal provided to the squeeze detection module corresponds to the sensing signal. Various pressure sensing devices for detecting squeezes in open roof assemblies are known in the art. For example, elongated sensors with a pressure-dependent resistance are known, wherein a voltage is applied across the terminals of the sensor, and when pressure is applied to the sensor at any position, the resistance decreases. The change in current can be used as the sensor signal, or, using another circuit, the voltage can be used as the sensor signal. Such a sensor signal can be used as an input signal for a squeeze detection module according to the present invention.

[0020] In another aspect, the present invention provides a method for operating an open roof assembly for use in a roof of a vehicle, wherein the open roof assembly includes a movably arranged closure member for closing an opening in the roof and a squeeze detection module for detecting squeeze of an object between the closure member and an edge of the opening. The squeeze detection module is operatively coupled to receive an input signal and is configured to detect the squeeze based on the input signal and a threshold value. The method includes dynamically determining the threshold value based on the input signal.

[0021] In one embodiment, the method comprises the steps of: receiving the input signal; determining the threshold value based on the input signal; detecting the squeeze by comparing the input signal with the determined threshold value; and repeating the previous steps.

[0022] In another embodiment, the step of determining the threshold includes the steps of: normalizing the input signal to obtain a normalized input signal; limiting the rate of change of the normalized input signal over time; determining an input compensation value based on the normalized input signal; providing a threshold deviation value; determining an input saturation value based on the input signal; and combining the input compensation value, the input saturation value and the threshold deviation value to obtain the threshold.

[0023] In another aspect, the present invention provides a computer software product comprising computer-readable and executable instructions for instructing a computer processor to perform the method steps according to the above aspects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further scope of application of the present invention will become apparent from the detailed description given below. However, it should be understood that the detailed description and specific examples, although indicating embodiments of the present invention, are given by way of example only, since various changes and modifications within the scope of the present invention will become apparent to those skilled in the art from this detailed description with reference to the accompanying drawings, in which:

[0025] Figure 1A A perspective view showing a vehicle roof having an open roof assembly;

[0026] Figure 1B Show Figure 1A An exploded view of the open roof assembly;

[0027] FIG. 2A shows a perspective view of an embodiment of an open roof assembly according to the present invention;

[0028] FIG. 2B illustrates a perspective cross-sectional view of a pressure sensitive device for use in the embodiment of FIG. 2A ;

[0029] FIG. 2C illustrates a cross-sectional view of a portion of the embodiment of FIG. 2A ;

[0030] Figure 3A shows a circuit diagram illustrating an embodiment of a squeeze detection module according to the present invention;

[0031] Figure 3B shows an exemplary graph for determining a saturation parameter;

[0032] Figures 4A-4D Graphs showing an exemplary input signal, a normalized input signal, a signal offset, and a threshold value according to a first experiment, respectively;

[0033] Figure 5 Graphs showing exemplary normalized input signals and threshold values ​​according to a first experiment, respectively;

[0034] Figure 6 Graphs showing exemplary normalized input signals and threshold values ​​according to a second experiment, respectively; and

[0035] Figures 7A-7F Graphs showing exemplary input signals, normalized input signals, threshold values, etc. according to the third experiment are shown respectively. DETAILED DESCRIPTION

[0036] The present invention will now be described with reference to the drawings, wherein the same reference numerals are used throughout the several views to identify the same or similar elements.

[0037] Figure 1A A vehicle roof 1 having an open roof assembly arranged therein is shown. The open roof assembly includes a movable panel 2a and a fixed panel 2b. The movable panel 2a is also referred to as a closing member because the movable panel 2a is movable over a first roof opening 3a so as to be able to open and close the first roof opening 3a. A wind deflector 4 is arranged at the front side of the first roof opening 3a.

[0038] In the illustrated embodiment, the movable panel 2a may be in a closed position, which is a position in which the movable panel 2a is arranged above the first roof opening 3a and closes the first roof opening 3a and is therefore generally arranged in the plane of the roof 1. Further, the movable panel 2a may be in an inclined position, which is a position in which the rear end RE of the movable panel 2a is raised compared to the closed position, while the front end FE of the movable panel 2a is still in the closed position. Further, the movable panel 2a may be in an open position, which is a position in which the movable panel 2a slides open and the first roof opening 3a is partially or completely exposed.

[0039] It should be noted that the roof 1 shown corresponds to a passenger car. However, the invention is not limited to passenger cars. Any other kind of vehicle that can be provided with a movable panel is also contemplated.

[0040] Figure 1B Shown as Figure 1A The same roof with panels 2a and 2b is shown in FIG. In particular, although Figure 1A The open roof assembly is shown in the open position, but Figure 1B is an exploded view of the open roof assembly in the closed position. Figure 1B In this exploded view of the , the presence of a second roof opening 3b is shown. The first and second roof openings 3a, 3b are provided in a frame 5 of the open roof assembly. An edge 5a of the frame 5 defines the first roof opening 3a.

[0041] The second roof opening 3b is arranged below the fixed panel 2b so that light can enter the vehicle interior space through the fixed panel 2b, assuming that the fixed panel 2b is a glass panel or a similar transparent panel, for example made of plastic material or any other suitable material. The second roof opening 3b and the transparent or translucent fixed panel 2b are optional and can be omitted in another embodiment of the open roof assembly.

[0042] The wind deflector 4 is generally a flexible material, such as a woven or nonwoven fabric with through holes arranged therein, or a mesh or net. The flexible material is supported by a support structure 4a (such as a rod-like or tubular structure), which is directly or indirectly hingedly connected to the frame 5 at a hinge 4b.

[0043] The wind deflector 4 is arranged in front of the first roof opening 3a and accommodates the airflow when the movable panel 2a is in the open position. In its raised position, the wind deflector 4 reduces inconvenient noise caused by the airflow during driving. When the movable panel 2a is in the closed position or in the tilted position, the wind deflector 4 is held downwardly below the front end FE of the movable panel 2a.

[0044] Typically, when the movable panel 2a slides to the open position, the wind deflector 4 is raised by the spring force, and when the movable panel 2a slides back into its closed position, the wind deflector 4 is pushed downward by the movable panel 2a. Figure 1A In FIG. 1 , the movable panel 2a is shown in an open position and the wind deflector 4 is shown in a raised position. Figure 1B In FIG. 1 , the movable panel 2a is shown in a closed position and the wind deflector 4 is correspondingly shown in a position in which it is held downwards.

[0045] Figure 1B A drive assembly having a first guide assembly 6a, a second guide assembly 6b, a first drive cable 7 and a second drive cable 8 is further shown. The first and second guide assemblies 6a, 6b are arranged on the respective side ends SE of the movable panel 2a and may each include a guide and a mechanism. The guide is coupled to the frame 5, while the mechanism includes a movable part and can be slidably moved in the guide. The first and second drive cables 7, 8 are arranged between the mechanism of the respective guide assemblies 6a, 6b and the electric motor 9.

[0046] The drive cables 7, 8 connect the electric motor 9 to the mechanism of the corresponding guide assembly 6a, 6b so that when the electric motor 9 is operated, the mechanism starts to move. In particular, the core of the drive cables 7, 8 is moved by the electric motor 9 to push or pull the mechanism of the corresponding guide 6a, 6b. Such drive assemblies are well known in the art and are therefore not further explained in this article. However, any other suitable drive assembly may also be adopted without departing from the scope of the present invention. Moreover, in a specific embodiment, the electric motor can be operatively arranged between the corresponding guide and the corresponding mechanism of the guide assembly 6a, 6b, and in such an embodiment, the drive assembly can be completely omitted.

[0047] In the illustrated embodiment, the guide assemblies 6a, 6b can start to move by raising the rear end RE of the movable panel 2a, so that the movable panel 2a is in a tilted position. Then, from the tilted position, the guide assemblies 6a, 6b can start to slide so that the movable panel 2a is in an open position. However, the present invention is not limited to such an embodiment. For example, in another embodiment, the movable panel 2a can be moved to the tilted position by raising the rear end RE, and the open position is reached by first lowering the rear end RE and then sliding the movable panel 2a under the fixed panel 2b or under any other structure or element arranged behind the rear end RE of the movable panel 2a. In other exemplary embodiments, the movable panel 2a can only be movable between the closed position and the tilted position or between the closed position and the open position.

[0048] In the illustrated embodiment, the electric motor 9 is mounted near or below the front end FE of the movable panel 2a at the recess 10. In another embodiment, the electric motor 9 may be positioned at any other suitable position or orientation. For example, the electric motor 9 may be arranged near or below the rear end RE of the movable panel 2a or below the fixed panel 2b.

[0049] The control unit 11 is schematically shown and is operatively coupled to the electric motor 9. The control unit 11 may be any kind of processing unit well known to those skilled in the art: a software controlled processing unit or a dedicated processing unit, such as an ASIC. The control unit 11 may be a stand-alone control unit, or it may be operatively coupled to another control unit, such as a multi-purpose general vehicle control unit. In yet another embodiment, the control unit 11 may be embedded in or be part of such a general vehicle control unit. In essence, the control unit 11 may be implemented by any control unit that is suitable, capable and configured to perform the operation of the electric motor 9 and thus the movable roof assembly.

[0050] FIG. 2A shows Figure 1A As an enlarged portion of a perspective view of an embodiment of the present invention. In particular, in this embodiment, two pressure sensing devices 30 are provided: one at the front edge portion of the closing member 2a and the other at the rear edge portion of the closing member 2a. In another embodiment, for example, such a pressure sensing device 30 may be additionally or alternatively provided on the side edge portion of the closing member 2a or on the edge 5a of the frame 5. Further, it should be noted that the use of the pressure sensing device 30 is merely an embodiment of the present invention, and the present invention may be implemented in a different manner without using the pressure sensing device 30.

[0051] FIG. 2B shows a detailed view of an exemplary pressure sensing device 30. The pressure sensing device 30 includes a compressible base layer 31 and a set of electrodes 32, wherein the set of electrodes includes at least two electrodes. The compressible base layer 31 can be formed of any type of suitable base material, such as a foam, a woven material, or a non-woven material, wherein the material is substantially non-conductive. Conductive particles can be provided in the compressible base material so that when the base material is compressed, the conductive particles can form a conductive path, thereby reducing the resistance of the compressible base layer 31. Other embodiments are also known from the prior art. Compression of the pressure sensing device 30 can be detected by the set of electrodes 32 by measuring the resistance of the compressible base layer 31. For example, using a well-known electronic circuit diagram, the induced voltage on the terminals of the set of electrodes 32 can be used as a measure of the resistance of the pressure sensing device 30.

[0052] Figure 2C shows the embodiment of Figure 2A in more detail. As shown, the closure member 2a comprises a glass panel 21 covered in its edge portion with a PU encapsulation 22 well known in the art. The pressure applied on the PU encapsulation is transmitted to the pressure sensing device 30.

[0053] The pressure sensing device 30 is arranged at a corner portion of the glass panel 21 so that the pressure sensing device 30 has a first portion arranged on a main surface of the glass panel 21 and has a second portion arranged on an edge surface of the glass panel 21, wherein the second portion is substantially perpendicular to the first portion. Therefore, the pressure sensing device 30 is suitably arranged for detecting pressure from multiple directions, in particular from the inside of the closure member 2a and at the front edge of the closure member 2a.

[0054] As described above, legal requirements may be applicable, wherein an object squeezed between the edge 5a of the frame 5 and the closure member 2a should not be squeezed by a force exceeding a predetermined maximum force (e.g. 100N). When the closure member 2a is closed by moving in the direction of arrow A, an object may be trapped between the edge 5a and the PU encapsulation 22 of the closure member 2a. As a result, the squeezed object will exert pressure on the PU encapsulation 22, which is transmitted to the pressure sensing device 30. The squeeze detection module operatively connected to the pressure sensing device 30 is configured to detect the applied pressure and control the movement of the closure member 2a to stop at least before exceeding the predetermined maximum force, and preferably reverse the closure member 2a to release any squeezed object.

[0055] FIG. 3 illustrates an embodiment of a squeeze detection module 40 according to the present invention, wherein the illustrated embodiment is configured for use with the pressure sensing device 30 shown in FIGS. 2A-2C .

[0056] The squeeze detection module 40 includes an input normalization module 42, a range limiter 43, and a threshold determination module 44. The threshold determination module 44 includes an input saturation compensation module 45 and an input compensation module 46.

[0057] In more detail, an input signal IS is received. In this embodiment, the input signal IS corresponds to a sense signal provided by the pressure sensing device 30. For example, the sense signal, and therefore the input signal IS, is a voltage signal, wherein the amplitude of the input signal IS corresponds to the amount of pressure applied to the pressure sensing device 30. The input signal IS may include a signal offset, wherein the value of the signal offset may vary over time. The variation may be related to the electrical properties of the pressure sensing device 30 and the connected circuit. Further, the signal offset may be related to the mechanical properties of the pressure sensing device 30. For example, when pressure is applied and the pressure sensing device 30 is then relaxed, the pressure sensing device 30 may require a certain amount of time to relax to its original state, due to which the sense signal will only slowly recover to its original amplitude. There may also be other reasons for the varying amplitude of the signal offset of the input signal IS. In any case, the signal offset is irrelevant to the detection of the squeezed object. Therefore, the input signal IS is first normalized by the input normalization module 42 by removing the signal offset from the input signal IS to generate a normalized input signal NS. In particular, the illustrated embodiment of the input normalization module 42 includes a median filter 421 , a rate limiter 422 , and a subtraction element 423 .

[0058] The median filter 421 determines the median from a plurality of samples of the input signal IS. The number of samples is optional, wherein a smaller number results in an increased sensitivity to the change in the signal offset, while a larger number of samples results in an increased phase shift. Those skilled in the art can select a suitable number according to a specific application. Further, in order to remove the signal offset, other mathematical operations can be appropriately selected within the scope of the present invention according to the intended application.

[0059] In a practical embodiment where computing resources are limited, the number of samples can be selected at a reduced sampling rate compared to the sampling rate of the input signal IS. For example, if the input signal IS provides samples at a sampling rate of approximately 1 kHz and a suitable period for determining the median is selected to be approximately 1 second, computing resources are required to provide a memory for at least 1000 samples. In this particular embodiment, the sampling rate can be reduced by a factor of, for example, 100 to approximately 10 Hz. Then, in a time period of 1 second, only 10 samples need to be stored in the memory, thereby significantly reducing the required storage space. Considering the statistical properties of the median, it can be assumed that the median of 10 samples instead of 1000 samples only introduces a small and possibly negligible inaccuracy. In addition to reducing storage space, the processing power and time for determining the median of 10 samples are less than the processing power and time for determining the median of 1000 samples.

[0060] The rate limiter 422 receives the median value from the median filter 421 and evaluates the median value in view of the previous median value. As described above, the median value is expected to change only slowly. If the median value changes unexpectedly quickly, it can be assumed that the change may be caused by squeezing, in which case the change should not be considered as part of the signal offset. Therefore, the rate limiter 422 limits the change of the median value to a predetermined maximum value. In the case where the change of the median value exceeds the predetermined maximum value, the rate limiter 422 adjusts the median value to, for example, a value corresponding to the predetermined maximum change.

[0061] It should be noted that a rate limiter may not be needed. For example, in the case of only very fast changes to be detected, due to the characteristics of the median filter which considers sampling over a period of 1 s, any changes within this 1 s time frame may not be directly reflected in the median. Therefore, a sharp rise in the input signal IS will remain in the normalized input signal NS.

[0062] The subtraction element 423 receives the input signal IS and the rate limited median value as a representative value of the signal offset. The median value is subtracted from the input signal IS to remove the signal offset.

[0063] In one embodiment, rate limiter 422 may be configured to limit primarily positive changes while allowing negative changes. Since extrusion generates increased signal amplitudes rather than decreased signal amplitudes, negative values ​​representing decreased amplitudes cannot be used to detect extrusion. In such an embodiment, more negative changes are absorbed in the signal offset and the normalized input signal NS will have fewer negative values. However, as described below, in order to obtain a suitable adaptive threshold, it is necessary to maintain sharp negative changes in the normalized input signal.

[0064] The normalized input signal NS thus obtained is compared with a threshold value. According to the present invention, the threshold value is dynamically determined by the threshold determination module 44 based on the input signal IS. In the illustrated embodiment, the threshold value is determined based on three parts. First, a threshold deviation 441 is provided as a base value of the threshold value. The threshold deviation 441 is compensated by an input compensation value to adapt the threshold value to the offset level of the normalized input signal NS in the normalized input signal NS, and is compensated by a saturation value to compensate for the saturation of the pressure sensing device 30.

[0065] The saturation compensation module 45 receives the input signal IS, and the subtraction element 453 extracts the saturation voltage value U sat Subtract the input signal IS. Saturation voltage value U sat corresponds to a signal amplitude above which a squeeze can no longer be detected from the input signal IS, since the amplitude of the input signal IS can no longer rise sufficiently to a recognizable level.sat corresponds to the maximum value of the voltage across the terminals of the pressure-sensitive device, for example when fully compressed. In a practical embodiment, the saturation voltage value U sat is set low so that the amplitude of the input signal IS can increase significantly when the object is squeezed. In an exemplary embodiment, the maximum voltage on the terminals of the pressure sensing device can be about 5 V, while the saturation voltage value U sat Can be set to approximately 3.3 V.

[0066] Based on the amplitude of the input signal and the saturation voltage value U sat The saturation parameter can be obtained from a predetermined lookup table, a mathematical function or any other suitable method. Figure 3B The diagram shown represents the voltage difference U sat -U IS As long as the voltage difference is greater than about 1.7 V, the saturation parameter is equal to 1. When the voltage difference is less than about 1.7 V, the saturation parameter becomes less than 1, thereby reducing the threshold value by multiplication by multiplier 442. The reduced threshold value ensures that in the case of a small increase in the amplitude of the input signal IS, such as due to saturation of the pressure sensing device, the squeeze is still detected in a timely manner.

[0067] In the diagram shown, when the voltage difference is 0 V, the saturation parameter is approximately 0.1. In the case of a voltage difference below 0 V, the amplitude of the input signal IS is higher than the saturation voltage value U sat . In such a case, the saturation parameter may be selected to be 0 or even a negative value, such as -1, so that squeezing is automatically detected. In another embodiment, the saturation parameter may be selected to be 0.1, so that a very low threshold is produced. The selection of the saturation parameter is considered to be within the capabilities of the skilled person. In particular, depending on the characteristics of the input signal, the saturation parameter may exhibit different characteristics, for example, decreasing rather than increasing with increasing voltage difference. Moreover, in one embodiment, the saturation parameter may not be required and may therefore be omitted.

[0068] return Figure 3A , the input compensation module 46 receives the normalized input signal NS. The second median filter 461 determines the normalized signal offset as the basis for the threshold deviation 441 that compensates the offset level of the input signal IS by determining the median of the normalized input signal NS. Of course, as described above with respect to the median filter 421 of the input normalization module 42, the number of samples used to determine the median can be selected, and if necessary, a reduced sampling rate can be selected compared to the sampling rate of the normalized input signal NS to reduce the required resources.

[0069] The normalized signal offset is then added to the threshold deviation 441 by the adding element 462. The output of the adding element 462 is the output of the input compensation module 46, which is then multiplied by the saturation parameter from the saturation compensation module 45.

[0070] As described with respect to the input normalization module 42, large changes in the threshold are not expected and therefore changes in the threshold over time are limited by the rate limiter 443. As with the rate limiter 422 of the input normalization module 42, the rate limiter is optional and may not be necessary in certain embodiments. The output of the rate limiter 443 corresponds to the dynamically adaptive threshold TH according to the present invention.

[0071] As used herein, dynamically is intended to mean that the threshold is variable while receiving and processing the input signal. Such adjustment may be performed continuously, but may also be performed periodically or in response to the occurrence of a predetermined condition.

[0072] For comparison with the adaptive threshold TH, the normalized input signal NS is first input into a range limiter 43, which may, for example, remove any negative values ​​or any excessive values. Excessive values ​​may occur at the start-up of the open roof assembly (during which the squeeze detection module 40 is initialized). Due to the phase shift caused by the input normalization module 42 and due to the lower sampling rate of the median filter 421, a plurality of samples will have significantly larger values ​​at the beginning than after initialization. Therefore, the range limiter 43 may optionally be provided to adjust the normalized input signal NS for the comparator 48. In the present embodiment, the range limiter 43 removes any negative values ​​and is therefore configured to output a positive normalized input signal PNS.

[0073] The comparison element 48 compares the positive normalized input signal PNS with the adaptive threshold value TH and outputs a detection signal DS. If the positive normalized input signal PNS exceeds the threshold value TH, the detection signal DS will indicate that squeezing has occurred. The detection signal DS can be supplied to the control unit so that the control unit can stop or reverse the movement of the closing member.

[0074] exist Figures 4A-4D 2A-2C and 3A-3B are further shown, Figures 4A-4D The results of the first experiment are shown in Figure 2. Figure 4A In FIG. 1 , the sensing signal of the pressure sensing device 30 is shown as Figure 3A The input signal IS of the squeeze detection module 40 is . In this first experiment, the pressure sensing device 30 is arranged in the edge portion of the closing member of the open roof assembly according to FIGS. 2A-2C , except that the pressure sensing device 30 is not covered by the PU encapsulation 22 .

[0075] The horizontal axis represents time in seconds and the vertical axis represents voltage as a measure of the resistance of the pressure sensing device 30. The input signal IS fluctuates at a high frequency due to, for example, electrical noise, and at a low frequency due to other characteristics as described above. The signal offset is approximately 0.7 V at time = 0 s and approximately 0.75 V at time = 4.5 s. Therefore, there is a small change in the signal offset. The signal offset is removed by the input normalization module 42 and provided as Figure 4B Subtracting the normalized input signal NS from the input signal IS provides Figure 4C The signal offset shown in .

[0076] As from Figure 4B and 4C It can be clearly seen that the signal offset and the low-frequency fluctuations are removed from the input signal IS. Only the high-frequency fluctuations of the input signal IS remain in the normalized input signal NS having a maximum amplitude of approximately 0.1 V.

[0077] at the same time, Figure 4D The adaptive threshold TH shown in oscillates between about 0.48 V and about 0.55 V. Therefore, obviously, no squeeze is detected, since the (positive) normalized input signal (P)NS does not exceed the threshold TH at any time.

[0078] Evaluation of the adaptive threshold TH in more detail shows that the adaptive threshold TH clearly responds to the rise of the normalized input signal NS at time = 3.7-4.0 s. As the normalized input signal NS rises, although no squeeze is detected, the adaptive threshold adapts to the increased signal and also rises. When the normalized input signal NS falls back, the adaptive threshold TH also falls back to its threshold deviation value. Of course, due to the above-mentioned phase shift, the rise and fall of the threshold are delayed compared to the rise and fall of the normalized input signal NS.

[0079] Figure 5 The results of the second experiment are shown, which used the same setup as the first experiment. The horizontal axis represents time in seconds and the vertical axis represents voltage. The solid line represents the normalized input signal NS and the dotted line represents the adaptive threshold TH.

[0080] In a second experiment, squeezing was induced. The object used was a force measuring device with a spring constant of 10 N / mm, which corresponds to a relatively soft object. Figure 5 It is evident that the squeeze occurs at time = approximately 3.0 s and is detected quickly and the closure member is reversed within approximately 0.23 seconds. The force measuring device shows that the maximum force applied to the force measuring device is 27 N, which is well below the legal requirement of a maximum of 100 N.

[0081] Figure 6 The results of the third experiment are shown, which used the same setup as the first experiment. The horizontal axis represents time in seconds and the vertical axis represents voltage. The solid line represents the normalized input signal NS and the dotted line represents the adaptive threshold TH.

[0082] In a third experiment, squeezing was induced. The object used was a force measuring device, wherein the object had a spring constant of 65 N / mm, which corresponds to a relatively hard object. Figure 6 It is clear that the squeeze occurs at time = about 3.7 s and is detected quickly and the closure member is reversed within about 0.20 seconds. The force measuring device shows that the maximum force applied to the force measuring device is 41 N, which is well below the legal requirement of a maximum of 100 N.

[0083] The second and third experiments show that the squeeze detection module according to the present invention is able to detect soft object squeeze and is able to detect hard object squeeze, both detections being well within legal requirements.

[0084] Figures 7A-7F A fourth experiment is shown, which uses the same setup as the second experiment. Figures 7A-7C In 7E-7F, the horizontal axis represents time in seconds and the vertical axis represents voltage. Fig.7D , the horizontal axis represents time in seconds and the vertical axis represents the speed of the closing member.

[0085] In the fourth experiment, before setting the closure member to move at time t=about 11.5 s ( Fig.7D ), at time = about 4 s, place the hand on the pressure sensing device to partially saturate the pressure sensing device, as shown from Fig. 7A It is obvious that the input signal IS rises rapidly from about 0.75 V to about 2.75 V due to this.

[0086] exist Figure 7B , the solid line corresponds to the normalized input signal NS. The normalized input signal NS increases rapidly from time = approximately 4.0 s, which corresponds to the rapid increase of the input signal IS. The squeeze detection module then slowly returns the normalized input signal to a level of approximately 0 V while the hand remains on the pressure sensing device. The rate of return to 0 V is generated by the rate limiter of the input normalization module, thereby limiting the rate of increase of the signal excursion, as shown in FIG. Figure 7C as shown in .

[0087] With the hand kept on the pressure sensing device, the closing member is then controlled to move in the closing direction at time = approximately 11.5 s until the pressure sensing device collides with the force measuring device at time = approximately 13.3 s. Fig.7D The absolute value of the velocity of the closing member is shown. At about 11.5 s, the closing member starts to move in the closing direction with a velocity of about 6.5 (arbitrary units). Since a squeeze has been detected, at about 13.3 s, the absolute value of the velocity changes to about 14.5. The closing member has been reversed so that it moves in the opening direction. In this experiment, the velocity in the opening direction is higher than the velocity in the closing direction due to the orientation of the open roof assembly. The open roof assembly is oriented vertically, with the closing direction pointing upwards, i.e. the weight of the closing member must be overcome, while in the opening direction the gravity assists the movement.

[0088] return Fig. 7A , at about 13.3 s, there is a small peak in the input signal IS. This small peak is due to the squeeze. For safety reasons, even if a person holds his or her hand against the closure member before and during movement of the closure member as in the present embodiment, the squeeze detection module of the open roof assembly should be able to detect and respond to such a squeeze. It should be noted that at Figure 7B In the graph of , the same smaller peak is clearly present at about 13.3 s.

[0089] exist Fig. 7E In FIG. 4 , the positive normalized input signal PNS is shown by the solid line. The corresponding adaptive threshold TH is shown by the dotted line. At about 4.0 s, the positive normalized input signal PNS corresponds to the normalized input signal rising ( Figure 7B ). Later, the adaptive threshold TH starts to increase accordingly. Similarly, shortly after the positive normalized input signal starts to decrease, the adaptive threshold TH starts to decrease.

[0090] During a period of about 4.0 s to about 7.8 s, the positive normalized input signal PNS exceeds the adaptive threshold TH, and therefore, the squeeze detection module detects the occurrence of a squeeze. However, due to the fact that the closure member is not moving, the squeeze detection has no effect.

[0091] At approximately 13.3 s, i.e. when the compression occurs during the movement of the closing member, Fig. 7E shows a smaller peak in the positive normalized input signal PNS. Figure 7F The peak value due to the squeeze has a value of about 0.15 V, which is clearly below the deviation threshold of 0.5 V. Therefore, without the threshold adaptation according to the invention, the squeeze would not be detected.

[0092] After the squeeze is detected at about 13.3 s, the closure member is reversed and the force applied by the hand on the closure member first changes, and the hand is removed at about 14.2 s. The sharp drop in the input signal results in a negative adaptive threshold, as shown in Fig. 7E At about 15.2 s in FIG. Shortly thereafter, the adaptive threshold TH starts to rise again.

[0093] Due to the adaptive threshold TH of the squeeze detection module according to the invention, squeezes are detected in time to meet legal requirements despite the pre-applied pressure by the hand. Moreover, the maximum pressure applied during squeezes is comparable to the maximum pressure applied during squeezes without pre-applied pressure.

[0094] The adaptive threshold according to the present invention can be applied to any method or system that applies a threshold. Figure 3A Embodiments of the squeeze detection module are designed to account for the characteristics of a pressure sensing device as described herein. In any other application, the adaptive thresholds may be applied to any other set of properties of the relevant input signal. For example, the input signal may be received from a sensor or may be any other kind of signal, such as a motor supply current or a signal derived from such a motor supply current. In the specific example of an open roof assembly, the motor supply current and speed may be used to determine the torque generated. This torque may be observed to prevent squeezes with higher forces. The characteristics of the torque may then be used to design a specific compensation module to additionally or alternatively compensate for a specific response, such as Figure 3A The saturation compensation module 45 shown in FIG.

[0095] In another example, the input signal can be normalized by subtracting a reference signal, wherein the reference signal corresponds to the force along the trajectory of closing the closure member. For example, in a known open roof assembly, the moving closure member needs to push the windshield downward, thereby locally requiring higher forces. In such an open roof assembly, the threshold value can be lowered at such a location, and the input signal is compensated by the reference signal for the required higher force level. According to the present invention, in such an exemplary embodiment, similar to the saturation compensation module 45, the threshold value can be dynamically applied to the absolute value, and similar to the input compensation module 46, the threshold value can be dynamically applied to the normalized input signal level. As is apparent to those skilled in the art, any squeeze detection module that employs a threshold value for squeeze detection can be provided with a dynamically adaptive threshold value according to the present invention to increase sensitivity without increasing the possibility of false, incorrect detection.

[0096] Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention, and the present invention can be embodied in various forms. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but only as the basis for the claims, and as a representative basis for teaching those skilled in the art to utilize the present invention in various ways with any appropriate specific structure contemplated. In particular, the features proposed and described in separate dependent claims can be applied in combination, and any advantageous combination of such claims is therefore disclosed.

[0097] Further, it is contemplated that the structural elements may be generated by applying three-dimensional (3D) printing technology. Thus, any reference to a structural element is intended to encompass any computer executable instructions that instruct a computer to generate such a structural element by three-dimensional printing technology or similar computer-controlled manufacturing technology. Furthermore, any such reference to a structural element is also intended to encompass a computer-readable medium that carries such computer executable instructions.

[0098] Further, the terms and phrases used in this article are not restrictive, but provide an understandable description of the present invention. When used in this article, the terms "a" or "an" are defined as one or more than one. When used in this article, the term multiple is defined as two or more than two. When used in this article, the term another is defined as at least a second or more. When used in this article, the terms include and / or have are defined as including (that is, open language). When used in this article, the term connection is defined as connected, but not necessarily directly connected.

[0099] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications which would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

1. An open roof assembly for use in a roof (2b) of a vehicle, the open roof assembly comprising a movably arranged closing member (2a) for closing an opening (3a) in the roof and a squeeze detection module (40) for detecting squeeze of an object between the closing member and an edge of the opening, wherein the squeeze detection module is operatively coupled to receive an input signal (IS) and is configured to detect squeeze based on the input signal and a threshold value, wherein the squeeze detection module is configured to dynamically determine the threshold value based on the input signal, Wherein determining the threshold comprises: determining an input compensation value based on the input signal (IS) to adapt the threshold value to an offset level of a normalized input signal (NS), and combining a threshold deviation value and the input compensation value, wherein the normalized input signal (NS) is provided by normalizing the input signal (IS) with respect to the input offset by removing the input offset from the input signal before determining the threshold value, Features Determining an input compensation value includes determining a median value of one of the input signal (IS) and the normalized input signal (NS).

2. The open roof assembly according to claim 1, characterized in that The squeeze detection module (40) is configured to perform the steps of: a) receiving the input signal (IS); b) determining the threshold value based on the input signal; c) detecting squeeze by comparing the input signal with the threshold value determined in step b; and d) Repeat steps ac.

3. The open roof assembly according to claim 1, characterized in that A median value of the selected portion of the input signal is derived and subtracted from the input signal (IS) to provide the normalized input signal (NS).

4. The open roof assembly according to claim 3, characterized in that The rate of change of the median value over time is limited by the squeeze detection module (40).

5. The open roof assembly according to claim 1 or 2, characterized in that Determining the threshold value includes deriving an input saturation value from the input signal (IS) and combining a threshold deviation value and the input saturation value.

6. An open roof assembly according to claim 1 or 2, characterized in that The rate of change of the threshold over time is limited by the squeeze detection module (40).

7. An open roof assembly according to claim 1 or 2, characterized in that The open roof assembly is provided with a pressure sensing device (30) configured to output a sensing signal, wherein the pressure sensing device is arranged and configured to change the sensing signal when an object is squeezed, and wherein the input signal (IS) provided to the squeeze detection module corresponds to the sensing signal.

8. An open roof assembly according to claim 1 or 2, characterized in that The input signal (IS) is a sensor signal, a motor supply current or a signal derived from the motor supply current.

9. A method for operating an open roof assembly for use in a roof (2b) of a vehicle, the open roof assembly comprising a movably arranged closing member (2a) for closing an opening (3a) in the roof and a squeeze detection module (40) for detecting squeeze of an object between the closing member and an edge of the opening, wherein the squeeze detection module is operatively coupled to receive an input signal (IS) and is configured to detect the squeeze based on the input signal and a threshold value, wherein the method comprises dynamically determining the threshold value based on the input signal, Wherein determining the threshold comprises: determining an input compensation value based on the input signal (IS) to adapt the threshold to an offset level of a normalized input signal (NS), and combining a threshold deviation value and the input compensation value, wherein the normalized input signal (NS) is provided by normalizing the input signal (IS) with respect to the input offset by removing the input offset from the input signal before determining the threshold, Features Determining an input compensation value includes determining a median value of one of the input signal (IS) and the normalized input signal (NS).

10. The method according to claim 9, comprising the steps of: a) receiving the input signal (IS); b) determining the threshold value according to the input signal; c) detecting said squeezing by comparing said input signal with a threshold value determined in step b; and d) Repeat steps ac.

11. The method according to claim 10, wherein step b of the method further comprises the steps of: b1) normalizing the input signal (IS) with respect to the input offset to obtain a normalized input signal (NS); b2) limiting the rate of change of the normalized input signal over time; b3) determining an input compensation value based on the normalized input signal so as to adapt the threshold value to an offset level of the normalized input signal (NS); b4) providing a threshold deviation value; b5) determining an input saturation value based on the input signal; as well as b6) Combining the input compensation value, the input saturation value and the threshold deviation value to obtain the threshold value.

12. The method according to claim 9, characterized in that The input signal (IS) is a sensor signal, a motor supply current or a signal derived from the motor supply current.

13. A computer program product comprising computer readable and executable instructions for instructing a computer processor to perform the method steps for operating an open roof assembly for use in a roof (2b) of a vehicle according to any of the preceding claims 9-12.

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