Open roof assembly for a vehicle and method for operating the same

Abstract

An open roof assembly in a roof of a vehicle comprises a movably arranged closure member and a drive system operably coupled to the closure member for moving the closure member along a motion trajectory. The drive system comprises an electric motor and a control unit for controlling operation of the electric motor. The control unit comprises a mathematical model describing at least a part of the drive system, model parameters, and a motion reference field. The control unit is configured to update the model parameters based on received values of first drive system variables, determine values of the second drive system variables using the mathematical model, determine a comparison value by comparing the values of the second drive system values and corresponding reference values of the motion reference field, and detect a presence of an obstacle if the comparison value is outside a predetermined value range.

Description

TECHNICAL FIELD

[0001] The present invention relates to a convertible roof assembly for use in a roof of a vehicle. BACKGROUND

[0002] Convertible roof assemblies for use in a roof of a vehicle are known. In particular, the known convertible roof assemblies comprise a movably arranged closure member for selectively covering or at least partially exposing an opening in the roof. Further, a drive system is provided and operably coupled to the closure member for moving the closure member along a motion trajectory. The drive system comprises an electric motor and a control unit operably coupled to the electric motor for controlling the operation of the electric motor. Thus, the control unit is provided and configured for controlling the position and motion of the closure member.

[0003] The control unit of the known convertible roof assembly is further configured to detect the presence of an obstacle. In particular, a crush or jam against an object is to be detected as quickly as possible, for example, in order to comply with regulatory standards like the European ECE standard or the US FMVSS-118. In addition, it is known to perform a calibration by determining a motion reference field. The motion reference field describes reference values of at least one specific drive system variable depending on the position of the closure member along its motion trajectory. Thus, for example, in a calibration run, the closure member is moved from, for example, its open position to its closed position, and the torque generated by the electric motor is determined for a plurality of positions along the motion trajectory from the open position to the closed position. The determined torque values can be stored as the motion reference field. Then, in operational use, the generated torque is determined and compared to the corresponding reference value, i.e. the reference value at the corresponding position. If the generated torque deviates too much from the reference value, a crush or jam can be detected. It is noted that any other suitable drive system variable can be used instead of the torque.

[0004] In order to determine the generated torque or other drive system variable as the second drive system variable, a value of a measurable drive system variable can be received by the control unit as the first drive system variable and used in the calculation. In particular, a mathematical model can be employed to obtain the value of the second drive system variable using the first drive system variable.

[0005] However, in practice, the calculated value of the second drive system variable can deviate from the reference value even without an obstacle being present, so that a relatively large range of values around the reference value is provided as a threshold to prevent false detection of the presence of an obstacle. On the other hand, the large range of values reduces the sensitivity for obstacle detection, and thus a small range of values would be preferred. SUMMARY

[0006] It is an object of the present invention to provide a reliable and cost-effective open roof assembly with increased sensitivity for obstacle detection.

[0007] 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. In particular, the open roof assembly comprises a movably arranged closing member for selectively covering or at least partially exposing an opening in the roof, and a drive system operably coupled to the closing member for moving the closing member along a motion trajectory. The drive system comprises an electric motor and a control unit operably coupled to the electric motor for controlling operation of the electric motor and for receiving a first drive system variable. The control system comprises a mathematical model describing at least a part of the drive system, model parameters as used in the mathematical model, and a motion reference field describing reference values of a second drive system variable as a function of a position of the closing member along its motion trajectory. Further, the control unit is configured to update the model parameters based on a received value of the first drive system variable, to determine a value of the second drive system variable using the mathematical model, to determine a comparison value by comparing the value of the second drive system value and a corresponding reference value of the motion reference field, and to detect a presence of an obstacle if the comparison value is outside a predetermined value range.

[0008] The actual deviation of the calculated second drive system variable is at least partially due to production of parts of the open roof assembly and mounting of parts in the open roof assembly. Therefore, a mathematical model describing model parameters of at least a part of the drive system is not accurate for every manufactured open roof assembly. Even if the mathematical model is adapted to a specific drive system during manufacturing, in real situations influenced by e.g. temperature, driving conditions, aging, etc. the mathematical model will not adapt to the drive system in all conditions or can start to deviate over time. Therefore, according to the present invention, the mathematical model is continuously calibrated during normal operation. Based on the received first drive system variable, the model parameters of the mathematical model can be updated. Therefore, the mathematical model is continuously adapted to adapt to real conditions and influences associated with motion and operation of the open roof assembly. As a result, the determined value of the second drive system variable is more accurate and better corresponds to the reference value. This allows to reduce the detection threshold defined by the value range and accordingly to increase the sensitivity without increasing the chance of false detections. Further, due to the increased sensitivity, a crush can be detected faster and the maximum crush force can be reduced.

[0009] In embodiments, the steps of updating, determining the second drive system variable, determining the comparison value and detecting the presence of an obstruction are repeated as long as the closure member is moving and no obstruction is detected. Thus, during the movement of the closure member, the control unit repeatedly updates the model parameters and continues to do so until the movement of the closure member is stopped because the closure member has reached its destination position or an occlusion is detected.

[0010] In embodiments, the step of updating the model parameters is performed before the step of determining the value of the second drive system variable. In another embodiment, the step of determining the value of the second drive system variable is performed before the step of updating the model parameters. In yet another embodiment, the step of updating the model parameters and the step of determining the value of the second drive system variable are performed simultaneously. The order of these steps can be chosen based on requirements, for example. If the model parameters are updated first, the determination of the value of the second drive system variable can be performed using the updated model parameters, wherein in case of an occlusion, the occlusion can slightly influence the model parameters. On the other hand, if the value of the second drive system variable is determined first, the model parameters used in the mathematical model can be slightly influenced due to a delay between the time at which the value of the first drive system variable is established and the time at which the model parameters derived therefrom are applied. In either case, it can be considered and anticipated that this influence is negligible and both embodiments can function correctly. In the embodiment in which both steps are performed simultaneously, a certain calculation time can be saved, but additional calculation power can be required.

[0011] In embodiments, the control unit is configured to reverse the direction of movement of the closure member when an obstruction is detected. To ensure that the object is not stuck, the closure member can be moved in the opposite direction when an occlusion has been detected. This reversal can be required by law and can include reversing over a predetermined short distance or can include reversing over a longer distance, for example to a fully open position.

[0012] In embodiments, the mathematical model comprises a model of the electric motor. Suitable mathematical motor models are described in EP 3 503 333 A1, in particular in the description from paragraph

[0051] to paragraph

[0067] and in Figures 9 to 13, which paragraphs and related figures are incorporated herein by reference. For example, based on the determined motor model parameters, a motor torque and / or a load torque can be derived.

[0013] In an embodiment, the mathematical model comprises a model of the motion of the closure member. For example, the Newtonian equations of motion can be used to provide a suitable model. In particular, such a model is described in US6630808. The model described in US6630808 provides values for the spring stiffness and damping coefficient, which document is incorporated herein by reference in its entirety. In particular, the second method variant as described herein is applicable to the present invention. However, instead of using residues (as described with respect to Figure 2 the values for the stiffness and damping coefficient in the Newtonian equations of motion can be used. From the values for the stiffness and damping, the actual local force can be derived as a second drive system variable and can be compared to a reference value for this force. Thus, in this embodiment of the present invention, for example, the force derived from such spring stiffness and damping coefficient can be used to obtain the second drive system variable.

[0014] The first drive system variable is selected from the group comprising the motor supply voltage, the motor current and the motor speed. The values of these variables can be derived relatively easily without the need for expensive sensors or complex structures.

[0015] In an embodiment, the second drive system variable is selected from the group comprising the motor current, the closure member position, the force generated, the torque generated, the stiffness and damping coefficient or any derivative of the above variables with respect to time.

[0016] In an embodiment, the control unit is further configured to determine the presence of an obstacle based on a time derivative of the output of the mathematical model. In this embodiment, the output of the mathematical model can additionally be used for detecting a crush without the need for comparison to a motion reference field. Such a detection method is described in the above-mentioned patent publications EP3503333 and US6630808. This method of crush detection can be sensitive to different objects or environments compared to the method using a motion reference field. Thus, these methods can complement each other. More specifically, the method described in the above-mentioned patent applications determines the presence of an obstacle based on a sudden change in the value of a variable, whereas the method using a threshold determines the presence of an obstacle based on an absolute value. A slowly increasing variable can escape the above-mentioned prior art methods, whereas the method based on an absolute value can have a delay between the first crush contact and the actual crush detection.

[0017] In an aspect, the invention further provides a method of operating an open roof assembly. The open roof assembly comprises a movably arranged closure member for selectively covering or at least partially exposing an opening in a roof, and a drive system operably coupled to the closure member for moving the closure member along a motion trajectory. The drive system comprises an electric motor and a control unit operably coupled to the electric motor for controlling operation of the electric motor and for receiving at least one first drive system variable. The control system comprises a mathematical model describing at least a part of the drive system, model parameters as used in the mathematical model, and a motion reference field describing reference values of a second drive system variable as a function of a position of the closure member along its motion trajectory. The method comprises the control unit performing the steps of updating the model parameters based on the received at least one first drive system variable, determining a value of the second drive system variable using the mathematical model, determining a comparison value by comparing the value of the second drive system value and a corresponding reference value of the motion reference field, and detecting a presence of an obstacle if the comparison value is outside a predetermined value range.

[0018] In embodiments of the method, the steps of updating the model parameters, determining a value of the second drive system variable, determining a comparison value, and detecting a presence of an obstacle are repeated as long as the closure member is moving and no obstacle is detected.

[0019] In embodiments, the method further comprises the control unit performing the step of reversing a direction of motion of the closure member when an obstacle is detected.

[0020] In another aspect, the 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 invention. In particular, such a computer processor can be comprised in a control unit of an open roof assembly. BRIEF DESCRIPTION OF DRAWINGS

[0021] Further areas of applicability of the present invention will become apparent from the detailed description given below. It should be understood that the detailed description and specific examples, while indicating embodiments of the application, are given by way of illustration only, since various changes and modifications within the scope of the application will become apparent to those skilled in the art from this detailed description, which refers to the accompanying drawings.

[0022] Figure 1A a perspective view showing a roof with an open roof assembly;

[0023] Figure 1B a perspective view showing Figure 1A an open roof assembly of Fig. 1 in an exploded view;

[0024] Figure 2 Fig. 1 shows a top view of an embodiment of an open roof assembly with a movable closing member and a corresponding drive assembly; and

[0025] Figure 3A Fig. 2 shows a diagram illustrating a first embodiment of a control unit for use in an open roof assembly according to the present application;

[0026] Figure 3B Fig. 3 shows a diagram illustrating a mathematical electric motor model suitable for use in the present application;

[0027] Figure 4 Fig. 4 shows a diagram illustrating a second embodiment of a control unit for use in an open roof assembly according to the present application;

[0028] Figure 5 Fig. 5 shows a diagram illustrating a first embodiment of a method according to the present application; and

[0029] Figure 6 Fig. 6 shows a diagram illustrating a second embodiment of a method according to the present application. DETAILED DESCRIPTION

[0030] The present application will now be described with reference to the drawings, wherein identical or similar elements are identified with the same reference numerals in several views.

[0031] Figure 1A A roof 1 with an open roof assembly arranged therein is shown. The open roof assembly comprises a movable panel 2a and a fixed panel 2b. The movable panel 2a is also referred to as a closing member, since the movable panel 2a is movable over a first roof opening 3a, enabling opening and closing of the first roof opening 3a. A deflector 4 is arranged at a front side of the first roof opening 3a.

[0032] In the shown embodiment, the movable panel 2a can be in a closed position, which is a position in which the movable panel 2a is arranged over the first roof opening 3a and closes the first roof opening and thus generally in the plane of the roof 1. Further, the movable panel 2a can be in a tilted 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 can be in an open position, which is a position in which the movable panel 2a is slid open and the first roof opening 3a is partially or completely exposed.

[0033] It is noted that the shown roof 1 corresponds to a passenger car. However, the present application is not limited to passenger cars. Any other type of vehicle can also be envisaged, which can be provided with a movable panel.

[0034] Figure 1B shows a roof with panels 2a and 2b Figure 1A shows the open roof assembly in an open position, but Figure 1A shows the open roof assembly in an open position, but Figure 1B is an exploded view of the open roof assembly in a closed position. Furthermore, in Figure 1B the exploded view, it is shown that there is a second roof opening 3b. The first roof opening 3a and the second roof opening 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.

[0035] The second roof opening 3b is arranged below the fixed panel 2b such that light can enter the vehicle interior space through the fixed panel 2b, given that the fixed panel 2b is a glass panel or a similarly transparent panel, e.g. made of a plastic material or any other suitable material. The second roof opening 3b with the transparent or translucent fixed panel 2b is optional and can be omitted in another embodiment of the open roof assembly.

[0036] The wind deflector 4 is generally a flexible material, e.g. a woven cloth or a non-woven cloth or web or mesh with through-holes arranged therein. The flexible material is supported by a support structure 4a, e.g. a rod-like or tube-like structure, which is directly or indirectly hingedly coupled to the frame 5 at a hinge 4b.

[0037] The wind deflector 4 is arranged in front of the first roof opening 3a and regulates the air flow when the movable panel 2a is in the open position. In its raised position, the wind deflector 4 reduces the inconvenient noise due to air flow during driving. When the movable panel 2a is in the closed position or in the tilted position, the wind deflector 4 is pressed below the front end FE of the movable panel 2a.

[0038] Generally, the wind deflector 4 is raised by a spring force when the movable panel 2a is slid into the open position and is pushed down by the movable panel 2a when the movable panel 2a is slid back into its closed position. In Figure 1A the movable panel 2a is shown in the open position and the wind deflector 4 is shown in the raised position. In Figure 1B the movable panel 2a is shown in the closed position and the wind deflector 4 is accordingly shown in its pressed-down position.

[0039] Figure 1BA drive assembly with 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 guide assembly 6a and the second guide assembly 6b are arranged on respective side ends SE of the movable panel 2a and can each comprise a guide and a mechanism. The guide is coupled to the frame 5, while the mechanism comprises a movable part and is slidably movable in the guide. The first drive cable 7 and the second drive cable 8 are provided between the mechanism of the respective guide assembly 6a, 6b and the electric motor 9.

[0040] The drive cables 7, 8 couple the electric motor 9 to the mechanism of the respective guide assembly 6a, 6b such that upon operating the electric motor 9, the mechanism starts to move. In particular, the core of the drive cables 7, 8 is moved by the electric motor 9, thereby pushing or pulling the mechanism of the respective guide 6a, 6b. Such a drive assembly is well-known in the art and is therefore not further elucidated herein. Further, any other suitable drive assembly can also be employed without departing from the scope of the present invention. Moreover, in a particular embodiment, the electric motor can be operably arranged between the respective guide and the respective mechanism of the guide assembly 6a, 6b and in such an embodiment, the drive assembly can be completely omitted.

[0041] In the shown embodiment, the guide assemblies 6a, 6b can start to move with raising the rear end RE of the movable panel 2a, thereby bringing the movable panel 2a into the tilted position. Then, the guide assemblies 6a, 6b can start to slide from the tilted position to bring the movable panel 2a into the open position. However, the present invention is not limited to such an embodiment. For example, in another embodiment, the movable panel 2a is not only movable to the tilted position by raising the rear end RE, but reaches the open position by first lowering the rear end RE and then sliding the movable panel 2a under the fixed panel 2b or any other structure or element provided behind the rear end RE of the movable panel 2a. In a further exemplary embodiment, the movable panel 2a can only be movable between the closed position and the tilted position or only between the closed position and the open position.

[0042] In the shown 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 can be positioned at any other suitable position or location. For example, the electric motor 9 can be arranged near or below the rear end RE of the movable panel 2a or below the fixed panel 2b.

[0043] The control unit 11 is schematically shown and operably coupled to the electric motor 9. The control unit 11 can be any type of processing unit, a software controlled processing unit or a dedicated processing unit, such as an ASIC, all of which are well known to the skilled person. The control unit 11 can be a stand-alone control unit or it can be operably connected to another control unit, such as a multi-purpose, general vehicle control unit. In yet another embodiment, the control unit 11 can be embedded in or part of such a general vehicle control unit. Basically, the control unit 11 can be embodied by any control unit suitable, capable and configured for performing the operation of the electric motor 9 and thus the movable roof assembly.

[0044] Figure 2 A convertible roof assembly with a mechanical drive assembly is schematically shown. The convertible roof assembly comprises a movable closure member 2a for closing a first roof opening 3a, a fixed panel 2b and a support frame 12. The support frame 12 is arranged and configured to mount and support the convertible roof assembly on a body frame of a vehicle. In Figure 2 The movable closure member 2a is schematically coupled to a drive cable 16 by a coupling element 14. In practice and as shown in Figure 1A and Figure 1B The movable closure member 2a is arranged on the support frame 12 by guide assemblies 6a, 6b and each guide assembly 6a, 6b is operated by an associated drive cable 16. In the shown embodiment, the drive cable 16 is movable by the electric motor by an effective mechanical coupling with a suitable gear 18. The drive cable 16 and the gear 18 are comprised in a mechanical drive assembly which operably couples the electric motor 9 and the closure member 2a.

[0045] The gear 18 is mechanically coupled to the electric motor 9 which is operably coupled to the control unit 11. The control unit 11 can comprise an electronic control circuit, said control unit can comprise a computer processor. Furthermore, the control unit 11 can be operably coupled to one or more sensors. For example, a Hall sensor and typically two Hall sensors are arranged next to the electric motor 9 such that an alternating signal from the Hall sensor is received by the control unit 11, based on which the control unit 11 is able to derive the speed of the electric motor and the amount of displacement of the closure member. Other sensors can be provided and also coupled to the control unit 11. In particular, for use with the present invention described in more detail hereinafter, a voltage sensor for sensing the supply voltage of the electric motor and / or a current sensor for sensing the armature current of the electric motor can be suitably provided.

[0046] Especially when closing the closure member 2a, but also when opening, an object can be squeezed and jammed between, for example, the front edge of the closure member 2a and the support frame 12. To prevent damage to either the object and the convertible top assembly, convertible top assemblies are usually provided with a device that detects such squeezing and possible jamming. Safety regulations can define requirements for such a detection device, especially regarding the maximum force that can be generated on any jammed object. Generally, to make the applied force as small as possible, it is preferred that the squeezing with an object is detected as quickly as possible, even before the object is jammed. On the other hand, with a high sensitivity, the chance of false detection of such squeezing increases significantly. Therefore, in the prior art, the threshold for determining whether a squeezing has occurred is set relatively high, so that the detection of an actual squeezing is delayed, because the measurable effect of the squeezing first needs to increase above the detection threshold. According to the invention, Figure 3A An embodiment of the control unit 11 is shown that is configured to detect a squeezing as quickly as possible by enabling a lowering of the detection threshold without increasing the chance of false detection of a squeezing.

[0047] In Figure 3A The control unit 11 is operatively coupled to the electric motor 9. A sensor signal 31 is received from the electric motor 9 and a control signal 32 is sent to the electric motor 9. The sensor signal 31 can comprise a sensed value from one sensor or a plurality of sensed values from a plurality of respective sensors. For example, the above-mentioned Hall signal can be included in the sensor signal 31. In addition, the sensor signal can comprise one or more of the values of the supply voltage, the armature current and the motor speed of the electric motor 9. The control signal 32 can comprise a supply voltage for directly driving the electric motor 9, or can only be a signal for controlling an electric driver circuit configured to supply the supply voltage to drive the electric motor 9.

[0048] In this first embodiment of the control unit 11, one or more of the above-mentioned sensed values are fed as values of a first drive system variable to the mathematical model module 20. The mathematical model module 20 uses the values of the first drive system variable to determine an update of the model parameters as used in the mathematical model, for example stored in the mathematical model module.

[0049] The updated mathematical model is then made available, e.g. by the model parameter signal 33 making it available to the second drive system variable calculation module 22. Based on the model parameters, the mathematical model and the value of the first drive system variable, the second drive system variable calculation module 22 calculates a value for one or more second drive system variables. The second drive system variable can essentially be any kind of drive system variable, but preferably the second drive system variable as used in the present application relates to an effect that changes when the closure member is pressing an object. Furthermore, such a drive system variable is preferably constant over time and thus suitable for comparison with a previously detected and stored reference value.

[0050] For example, along the movement trajectory of the closure member, e.g. from an open position to a closed position, the mechanical resistance can vary, e.g. due to applied mechanisms or the presence of louvre arms. Thus, the motor torque or force to be applied for a normal movement can vary depending on the position of the closure member along the movement trajectory. However, such a variation is constant and repeatable. Thus, a movement reference field can be determined and stored, e.g. in the movement reference field storage 28. For performing the comparison, the second drive system variable should correspond to such a constant and repeatable variable of the drive system.

[0051] The value of the second drive system variable can be transmitted as a second variable signal 34 to the comparison and determination module 26. The comparison and determination module 26 further receives the movement reference field from the movement reference field storage 28 as a reference value signal 36, and the value range from the value range storage 24 as a value range signal 35.

[0052] In the comparison and determination module 26, the value of the second drive system variable received from the second drive system variable calculation module 22 is compared to the corresponding reference value received from the movement reference field storage 28. Such a comparison can comprise e.g. a subtraction, but can also comprise any other suitable kind of operation resulting in a comparison value. The comparison value can then be evaluated in terms of the value range. For example, if the comparison value is within the value range, it can be determined that no crushing or jamming has occurred. In another embodiment, it will be apparent to the skilled person that the value range can be configured to indicate that crushing or jamming has actually occurred.

[0053] If crushing is detected, the comparison and determination module 26 can be configured to output a crushing detection signal 37 indicating that crushing has been detected, and the control unit 11 is configured to initiate an immediate stop and preferably a reversal of the closure mechanism by the control signal 32.

[0054] Figure 3B A suitable mathematical model for use in the present application is shown, e.g. used in Figure 3Athe mathematical model in the mathematical model module 20 of the embodiment. The mathematical model is described in detail in EP3503333A1. Therefore, with respect to the detailed description of the operation of the model, reference is made to paragraphs

[0051] to

[0067] and figures 9 to 13 of EP3503333A1. It is noted that in this prior art disclosure, it is described that the occurrence of a squeeze is derived from a fast change in the disturbance observer In the present invention, the disturbance observer is only part of the mathematical model, ensuring correct and accurate operation of the model. In the present invention, the estimated motor model parameters are advantageously used to accurately determine actual drive system variables. The motor model parameters are present in the matrix and as is clear from equations 157 and 158 in figure 12 of EP3503333A1, which contain the internal friction B and inertia J of the motor, the armature resistance R a and inductance L a and the motor constants K t and K e Based on the estimated values for these motor model parameters, an accurate determination of derivable drive system parameters can be obtained. For example, an accurate calculation of the generated force or torque can be obtained, wherein the accuracy is not dependent on instant conditions, such as for example temperature or wear over time. The influence of such conditions would be established in the motor model parameters.

[0055] The mathematical model as shown in Figure 3B uses the supply voltage u, the rotor speed ω and the armature current I as inputs. These inputs can be measured directly by suitable sensors or can be derived indirectly. For example, the armature current I can be derived from the supply voltage u and the rotor speed ω as described in EP3503333A1, in particular with respect to figure 13.

[0056] Figure 4 A second embodiment of the control unit 11 according to the present invention is shown. The second embodiment corresponds to Figure 3A the first embodiment of the control unit 11, but with the addition of a second squeeze detection system and method, wherein the system and method according to the present invention can complement each other with the second squeeze detection system.

[0057] In the embodiment of Figure 4 the mathematical model module 20 and the second drive system variable calculation module 22 are provided and as described with respect to Figure 3AThe second drive system variable calculation module 22 outputs a second variable signal 34 to the comparison and determination module 26. Additionally, the mathematical model module 20 outputs a model signal 38 derived from the mathematical model. For example, the model signal 38 can correspond to a disturbance observer signal as described in EP 3 503 333 A1. The second determination module 42 receives the model signal 38 and evaluates the model signal 38 in terms of an associated threshold or value range received from a second value range storage 44 as a second value range signal 45, for example according to the method described in EP 3 503 333 A1. Then, a second crush detection signal 46 indicating whether a crush has been detected is supplied to the crush detection evaluation module 30, which further receives the crush detection signal 37 from the comparison and determination module 26. Based on both crush detection signals 37, 46, the crush detection evaluation module 30 is configured to determine whether a crush has actually occurred. For example, if either of the crush detection signals 37, 46 indicates that a crush has occurred, the crush detection evaluation module 30 can determine that a crush has actually occurred. In another embodiment, both crush detection signals can be required to indicate the occurrence of a crush for the crush detection evaluation module 30 to determine the actual occurrence of a crush. In a particular embodiment, the crush detection signals 37, 46 can indicate a number of opportunities that suggest that a crush has occurred, and the crush detection evaluation module 30 evaluates both numbers of opportunities to determine whether a crush has occurred.

[0058] Figure 5 An embodiment of the method according to the application is shown, wherein this embodiment of the method corresponds to the method performed in the embodiment of the control unit as Figure 3A presented.

[0059] In a first step S11, a value of a first drive system variable is received. In Figure 3BThe first drive system variable can be the supply voltage u, the rotor speed ω or the armature current I or any combination thereof. Based on this first drive system variable, in a second step S12, the model parameters of the mathematical model are re-determined and updated. Using the updated model parameters, in a third step S13, the second drive system variable is determined using the mathematical model. It is noted that in another embodiment, the second step S12 and the third step S13 can be performed in reverse order, but the accuracy of the second drive system variable can slightly decrease, since the estimation is then based on model parameters corresponding to another position along the movement trajectory of the closed member. In yet another embodiment, the second step S12 and the third step S13 can be performed simultaneously, i.e. in parallel, thereby reducing the time required to perform one iteration of the method. However, also in this embodiment, the accuracy of the second drive system variable can slightly decrease, since the estimation is then based on model parameters corresponding to another position along the movement trajectory of the closed member.

[0060] Returning to Figure 5 In a fourth step, the estimated second drive system variable is compared to a reference value of the movement reference field. In a fourth step S14, a comparison value is determined, which is used in a fifth step S15. In the fifth step S15, the comparison value is evaluated with respect to a threshold value or a predetermined value range to determine whether an obstacle is present, i.e. whether a jam or a pinch has occurred.

[0061] Figure 6 A second embodiment of the method embodied in the method of the control unit of Figure 4 is shown. In this second embodiment, the method steps Sll to S15 are similar to the embodiment of the method shown in Figure 5 Compared to the embodiment of Figure 5 , the second embodiment adds a sixth step S16, which performs a second pinch detection based on the model output, e.g. the change of the disturbance observer signal. If the change of the disturbance observer signal exceeds a threshold value, it is determined that a sudden change in the condition is present, which is assumed to be a pinch condition. In this embodiment, the fifth step S15 can comprise evaluating the results of the two pinch detection methods in order to finally determine and decide whether a pinch has occurred.

[0062] In this embodiment, advantageously a single mathematical model is employed in both different pinch detection systems, thereby requiring low computational power, while providing a complex and balanced pinch detection. In particular, if one system is more sensitive to a first kind of object, e.g. a hard object, and the other system is more sensitive to a second kind of object, e.g. a soft object, the sensitivity to different objects, e.g. hard and soft objects, can be optimized.

[0063] Detailed embodiments of the application are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the application. Accordingly, the specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present application in virtually any appropriately detailed structure. In particular, features described in separate dependent claims can be combined and thus the disclosure of any advantageous combination of such claims is disclosed.

[0064] Further, it is contemplated that the structural elements can be produced by applying three-dimensional (3D) printing technology. Thus, any reference to a structural element is intended to encompass any computer executable instructions instructing a computer to produce such a structural element by three-dimensional printing technology or similar computer controlled manufacturing technology. Further, any such reference to a structural element is also intended to encompass a computer readable medium carrying such computer executable instructions.

[0065] Further, the terms and phrases used herein are not intended to be limiting, but rather to provide an understandable description of the application. The term "one" or "a" as used herein is defined as one or more than one. The term plurality as used herein is defined as two or more than two. The term another as used herein is defined as at least a second or more. The terms including and / or having, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.

[0066] This having thus described the application, it will be obvious to those skilled in the art that many changes can be made in the form, detail and implementation thereof. Such changes are not to be regarded as a departure from the spirit and scope of the application, and all such modifications as 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 the roof of a vehicle, the open roof assembly comprising: A movable closure member for selectively covering or at least partially exposing an opening in the roof; and a drive system operatively coupled to the closing member for moving the closing member along a motion trajectory. The drive system includes an electric motor and a control unit, the control unit being operatively coupled to the electric motor for controlling the operation of the electric motor and for receiving a first drive system variable. The control unit includes • A mathematical model that describes at least a portion of the drive system; • Model parameters used in the mathematical model described; as well as • Motion reference field, which describes a reference value for a second drive system variable based on the position of the closed member along its motion trajectory; and The control unit is configured as follows a. Update the model parameters based on the received values ​​of the first driving system variables; b. Use the mathematical model to determine the values ​​of the second drive system variables; c. Determine a comparison value by comparing the value of the second drive system with the corresponding reference value of the motion reference field; as well as d. If the comparison value is outside the predetermined range, the presence of an obstacle is detected.

2. The open roof assembly of claim 1, wherein steps a to d are repeated as long as the closing member is moving and no obstacle is detected.

3. The open roof assembly of claim 1, wherein step a is performed before step b.

4. The open roof assembly of claim 1, wherein step b is performed before or simultaneously with step a.

5. The open roof assembly of claim 1, wherein the control unit is configured to e. When an obstacle is detected in step d, the direction of movement of the closing member is reversed.

6. The open roof assembly of claim 1, wherein the mathematical model includes a model of the electric motor.

7. The open roof assembly of claim 1, wherein the mathematical model includes a model of the motion of the closing member.

8. The open roof assembly of claim 1, wherein the first drive system variable is selected from the group consisting of motor supply voltage, motor current and motor speed.

9. The open roof assembly of claim 1, wherein the second drive system variable is selected from the group consisting of motor current, closing member position, generated force and generated torque, or any derivative of the above variables with respect to time.

10. The open roof assembly of claim 1, wherein the control unit is further configured to: f. Determine the presence of obstacles based on the time derivative of the output of the mathematical model.

11. A method of operating an open roof assembly, the open roof assembly comprising: A movable closure member for selectively covering or at least partially exposing an opening in the roof; and a drive system operatively coupled to the closing member for moving the closing member along a motion trajectory. The drive system includes an electric motor and a control unit, the control unit being operatively coupled to the electric motor for controlling the operation of the electric motor and for receiving at least one first drive system variable. The control unit includes • A mathematical model that describes at least a portion of the drive system; • Model parameters used in the mathematical model described; as well as • A motion reference field, which describes a reference value for a second drive system variable based on the position of the closed member along its motion trajectory; and The method includes the control unit performing the following steps. a. Update the model parameters based on at least one received first driving system variable; b. Use the mathematical model to determine the values ​​of the second drive system variables; c. Determine the comparison value by comparing the value of the second drive system with the corresponding reference value of the motion reference field; as well as d. If the comparison value is outside the predetermined range, the presence of an obstacle is detected.

12. The method of claim 11, wherein steps a to d are repeated as long as the closing member is moving and no obstacle is detected.

13. The method of claim 11, wherein the method further comprises the control unit performing the following steps: e. When an obstacle is detected in step d, the direction of movement of the closing member is reversed.

14. A computer software product comprising computer-readable and executable instructions for instructing a computer processor to perform steps of the method according to any one of claims 11 to 13.

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