Belt path monitoring system using both a belt extension sensor and an interior sensor

Abstract

System (10), comprising: a seat belt routing module (90) configured to: Determining the path of a safety belt (16) relative to an occupant on a seat (14) of a vehicle based on an input from a webbing extension sensor (33, 34) that measures webbing extension of the safety belt (16); and Determining the seat belt path based on an input from an interior sensor (57) located in an interior of the vehicle, the interior sensor (57) comprising at least one of: a camera, an infrared sensor, an ultrasonic sensor, a radar sensor, and a lidar sensor; and a user interface device (UID) control module (92) configured to control a user interface device (54) to indicate that the seat belt (16) is not properly fastened when: the seat belt path determined using the belt extension sensor (33, 34) and / or the interior sensor (57) is incorrect; and the seat belt path determined by the belt webbing extension sensor (33, 34) corresponds to the seat belt path determined by the interior sensor (57); characterized in that the system (10) further comprises a sensor condition module (88) configured to activate the interior sensor (57) when a first change in belt webbing extension is greater than a first delta value and when a buckle sensor (32) indicates that the seat belt (16) is closed; and wherein the sensor condition module (88) is further configured to deactivate the interior sensor (57) if, after the seat belt path module (90) has determined the seat belt path using the interior sensor (57), a second change in belt webbing extension is less than a second delta value and the buckle sensor (32) still indicates that the seat belt (16) is closed.

Description

INTRODUCTION

[0001] The present invention relates to a system according to the preamble of claim 1 for monitoring the belt path using a belt pull-out sensor and an interior sensor, as is essentially known from DE 10 2017 009 573 A1.

[0002] With regard to the further state of the art, reference is made at this point to the documents DE 10 2016 014 867 A1, DE 11 2017 004 754 T5, US 2017 / 012 94 35 A1, DE 10 2007 021 700 A1, CN 1 1065 43 43 A and US 2019 002 32 09 A1.

[0003] A seatbelt assembly in a vehicle, which may be an autonomous vehicle, typically includes a seatbelt webbing attached to a tongue or latch plate, a seatbelt buckle, a retractor, a lower anchor, and possibly a guide loop or D-ring through which the seatbelt webbing passes. There are also seatbelt systems that may include a second retractor at the lower anchor. The seatbelt may include both lap and shoulder belts. When the seatbelt is buckled, the lap belt webbing extends from a first side of a vehicle seat to a buckle on a second side of the seat. The shoulder belt extends diagonally from over an occupant's shoulder on the first side of the seat to the buckle on the second side of the seat.In many cases, the shoulder and lap belts can be a single strap, and the strap can be slidably routed through the tongue or locking plate, as in a single-reel system. Alternatively, the shoulder and lap belts can be two separate straps and attached to the tongue or locking plate for a dual-reel system.

[0004] The retractor contains a spool for paying out and retracting the seat belt webbing. An occupant can pull the webbing to withdraw the desired length of webbing from the retractor. The occupant can insert the tongue into the buckle to secure the webbing around the occupant or child seat. The occupant can press a button on the buckle to release the tongue and allow the spool to retract the webbing back into the retractor. SUMMARY

[0005] According to the invention, a system for monitoring the belt path using a belt extension sensor and an interior sensor is proposed, which is characterized by the features of claim 1.

[0006] In one example, the sensor condition module is configured to activate the seat belt extension sensor when a buckle sensor indicates that the seat belt is closed or locked.

[0007] In one example, the belt routing module is configured to repeatedly determine the belt routing based on input from the interior sensor when the interior sensor is enabled.

[0008] In one example, the belt path module is configured to (i) determine a plurality of possible belt paths based on the belt webbing extension and (ii) determine that the belt path determined using the belt webbing extension sensor corresponds to the belt path determined using the interior sensor if one of the plurality of possible belt paths matches the belt path determined using the interior sensor.

[0009] In one example, the belt path module is configured to (i) determine a plurality of possible belt paths based on the input from the interior sensor, and (ii) determine that the belt path determined using the webbing extension sensor corresponds to the belt path determined using the interior sensor if one of the plurality of possible belt paths matches the belt path determined using the webbing extension sensor.

[0010] In one example, if the belt path determined using the webbing extension sensor does not correspond to the belt path determined using the interior sensor, the belt path module is configured to select either the webbing extension sensor or the interior sensor as the primary sensor, and the UID control module is configured to control the user interface device to indicate that the seat belt is not properly fastened if the belt path determined using the primary sensor is not proper.

[0011] In one example, the belt path module is configured to select either the webbing extension sensor or the interior sensor as the primary sensor based on at least one of the following: (i) whether the interior sensor detects a shoulder webbing of the seat belt, (ii) a confidence in the belt path determined by the webbing extension sensor, and (iii) a confidence in the belt path determined by the interior sensor.

[0012] In one example, the system further includes an occupant posture module configured to determine a posture of the occupant based on the input from the interior sensor, and the belt routing module configured to select the interior sensor as the primary sensor when the occupant posture is not upright.

[0013] In one example, the belt path module is configured to (i) store a relationship between the webbing extension and the belt path and (ii) determine the belt path based on the webbing extension using the stored relationship between the webbing extension and the belt path.

[0014] In one example, the belt routing module is configured to adjust the stored relationship when a buckle sensor indicates that the seat belt is fastened and an acceleration sensor indicates that a deceleration of the vehicle is greater than a predetermined rate.

[0015] In one example, the belt routing module is configured to adjust the stored relationship when a buckle sensor indicates that the seat belt is fastened and the belt routing module determines that the seat belt is properly fastened based on input from the interior sensor.

[0016] In one example, the belt routing module is configured to adjust the stored relationship when the belt routing module determines that the seat belt is properly stowed based on input from the interior sensor.

[0017] In one example, the system further includes an occupant detection module configured to detect whether a child restraint seat is present on the vehicle seat, and the belt routing module configured to adjust the stored relationship based on whether the child restraint seat is present on the vehicle seat.

[0018] In one example, the belt routing module is configured to adjust the stored relationship when (i) the interior sensor and / or a seat bottom position sensor indicates that the vehicle seat has moved and the belt routing module determines that the seat belt is properly fastened based on the input from the interior sensor.

[0019] In one example, the belt routing module is configured to adjust the stored relationship when (i) the interior sensor and / or a guide loop position sensor indicates that a guide loop for the seat belt has moved, and (ii) the belt routing module determines that the seat belt is properly fastened based on the input from the interior sensor.

[0020] A second example of a system according to the present invention includes a belt path module and a user interface device (UID) control module. The belt path module is configured to (i) determine a path of a seat belt relative to an occupant in a seat of a vehicle based on input from a webbing extension sensor that measures webbing extension of the seat belt, (ii) determine the belt path based on input from an interior sensor located in an interior of the vehicle, (iii) assign a first confidence to the belt path determined using the webbing extension sensor, (iv) assign a second confidence to the belt path determined using the interior sensor, and (v) select the webbing extension sensor or the interior sensor as a primary sensor based on the first and second confidences.The interior sensor includes at least one of: a camera, an infrared sensor, an ultrasonic sensor, a radar sensor, and a lidar sensor. The UID control module is configured to control a user interface device to indicate that the seat belt is not properly fastened if the belt path determined by the primary sensor is incorrect.

[0021] In one example, the belt routing module is configured to (i) select the belt webbing extension sensor as the primary sensor when the first confidence is greater than the second confidence, and (ii) select the interior sensor as the primary sensor when the second confidence is greater than the first confidence.

[0022] In one example, the belt path module is configured to (i) assign the first confidence based on whether the belt path determined with the belt webbing extension sensor is a lap belt path or a shoulder belt path, and (ii) assign the second confidence based on whether a field of view of the interior sensor is obstructed.

[0023] Further areas of applicability of the present invention will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are provided for purposes of illustration only. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will become more fully apparent from the detailed description and the accompanying drawings, in which: Fig. 1 is a schematic view of an exemplary vehicle system according to the present invention; Fig. 2 is a functional block diagram of an exemplary control system according to the present invention; Fig. 3 is a flowchart illustrating a first exemplary method for monitoring belt path using both a belt retraction sensor and an interior sensor; Fig. 4 is a flowchart illustrating a second exemplary method for monitoring belt path using both a belt retraction sensor and an interior sensor; Fig. 5A and Fig. 5B are flowcharts showing example methods for selecting a belt retraction sensor or an interior sensor as the primary sensor for monitoring belt path; Fig. 6 is a flowchart illustrating an exemplary method for accounting for changes in occupant and seat posture when monitoring belt routing; Fig. 7 is a flowchart showing an exemplary method for accounting for changes in webbing extension due to rapid braking when monitoring webbing travel; Fig. 8 is a flowchart illustrating an exemplary method for accounting for an occupant unfastening a seat belt during a trip when monitoring belt routing; Fig. 9 is a flowchart illustrating an exemplary method for adjusting a stored relationship between spool position and webbing extension when the seat belt is stowed; Fig. 10 is a flowchart illustrating an exemplary method for adjusting a stored relationship between belt webbing extension and belt path when a child restraint seat is in a vehicle seat; Fig. 11 is a flowchart showing an exemplary method for incorporating changes in seat position when monitoring belt routing; Fig. 12 is a flowchart showing an exemplary method for accounting for changes in guide loop position when monitoring belt path; and Fig. 13 is a flowchart showing an exemplary method for monitoring belt tracking relative to a tracking guide.

[0025] In the drawings, reference numerals may be reused to designate similar and / or identical elements. DETAILED DESCRIPTION

[0026] A system and method may use the output of a buckle sensor and a belt extension sensor to determine whether the seat belt is properly fastened. The buckle sensor detects whether a tongue or locking plate of a seat belt is inserted into and / or secured within a buckle. The belt extension sensor detects the extension, or length, of the seat belt extended from a seat belt retractor. In one example, the belt extension sensor detects a rotational position of a spool within the seat belt retractor and uses a predetermined relationship between the spool position and webbing extension to determine webbing extension.

[0027] In one example, the system and method determines that the seat belt is properly fastened when the buckle sensor indicates that the seat belt is fastened and the belt webbing sensor indicates that the seat belt is properly routed. The system and method determines the seat belt routing based on the output of the seat belt webbing sensor using a known or stored relationship between seat belt webbing and seat belt routing. The system and method determines that the belt routing is proper when the belt webbing is within a predetermined range.

[0028] The buckle sensor and the belt extension sensor have low power consumption. Thus, the system and method determines whether a seat belt is properly fastened based on the output of the buckle sensor and the belt extension sensor without consuming a lot of power. However, the system and method may have difficulty determining belt routing based on belt webbing extension under certain conditions. For example, the system and method may have difficulty determining seat belt routing using the belt extension sensor if the seat belt is routed under an occupant's arm. Also, when determining belt routing using the belt extension sensor, the system and method may have difficulty distinguishing between the belt routing around a child seat and the belt routing around a small, forward-facing child.In addition, the system and method may have some difficulty determining whether a safety belt has been routed over or through the routing guides formed by the belt guide wings on a backless booster type child restraint seat or whether the safety belt has been routed through a belt routing guide on the seat bottom.

[0029] In addition, the relationship between webbing extension and belt path can be affected by various events. These events include the posture of an occupant in the vehicle seat becoming less than upright, the occurrence of a rapid braking situation, the refastening of the seat belt by a occupant in the vehicle seat, the installation of a child safety seat in the vehicle seat, the movement of the vehicle seat position, and / or the movement of the position of a seat belt guide loop. Thus, the occurrence of any of these events may cause the system and method to inaccurately determine the belt path.

[0030] A system and method can determine the routing of a seat belt based on the output of an interior sensor, such as a camera mounted in the interior of a vehicle. In one example, the system and method detects edges or surfaces of objects in an image captured by the interior sensor and determines the sizes, shapes, and / or positions of the objects based on the detected edges or surfaces. The system and method then determines whether the objects correspond to a seat, a seat belt, and / or an occupant in the seat based on the sizes, shapes, and / or positions of the objects. The system and method then determines the routing of the seat belt based on the relative positions of the seat belt and the occupant, skeletal features of the occupant, and / or facial features of the occupant such as eyes, nose, mouth, ears, chin, or a combination of these features.

[0031] Determining the belt routing based on the output of the interior sensor has several advantages. First, it allows the system and method to distinguish between different shoulder belt routes and lap belt routes. Second, it allows the system and method to detect the presence of a child safety seat. Third, it allows the system and method to detect when the seat belt webbing is twisted. Fourth, it can enable the system to determine if a seat belt has been routed over or through the routing guides formed by the belt guide wings on a backless booster seat or through fully closed belt routing guides on a child restraint seat. Fifth, it can enable the system to determine if the seat belt has been routed through a seat belt routing guide on the seat bottom.

[0032] However, there are some disadvantages to determining seat belt routing based on the output of the interior sensor. For example, the system and method may have difficulty detecting seat belt routing if the seat belt is obscured or hidden from the view of the interior sensor. Furthermore, the system and method may have difficulty detecting seat belt routing under certain lighting conditions. Furthermore, the interior sensor and associated vehicle interior lighting devices together consume a lot of power, which may affect the vehicle's driving range when the system is operating.

[0033] A system and method according to the present invention determines whether a seat belt is properly fastened using a buckle sensor, a belt retraction sensor, and an interior sensor. The system and method determines whether a seat belt is properly fastened by utilizing all three types of sensors in a manner that leverages their advantages while minimizing their disadvantages. In one example, the system and method continuously supplies power to the buckle sensor and the belt retraction sensors and monitors their output to determine whether the seat belt is properly fastened.

[0034] The system and method also periodically supplies power to the interior sensor and monitors its output to determine whether the seat belt is properly fastened. In one example, the system and method only supplies power to the interior sensor when one of the confirmation events that affect the relationship between webbing extension and belt path occurs. When one of these events occurs, the system and method uses the interior sensor to determine belt path and adjusts the stored webbing extension to belt path relationship if necessary. Thereafter, the system and method stops supplying power to the interior sensor and determines belt path based on the output of the belt extension sensor using the adjusted stored relationship.

[0035] In this way, the system and method utilize the interior sensor to improve the accuracy of the belt path determined by the belt retraction sensor. Furthermore, the system and method use the interior sensor only when necessary to minimize the energy required to determine the belt path or under conditions that make accurate belt path determination using the belt retraction sensor alone difficult. Furthermore, after the belt path has been determined, the system and method can choose between the belt retraction sensor and the interior sensor based on the confidence levels of these sensors associated with the determined belt path. For example, if the seat belt is routed behind an occupant's back such that the seat belt is at least partially obscured from the field of view of the interior sensor, the confidence of the interior sensor regarding this seat belt path may be low.Therefore, the system and method may decide to use the belt retraction sensor to detect this type of seat belt path.

[0036] According to Fig. 1, an exemplary vehicle system 10 includes an interior 12 with a seat 14 having a safety belt 16. The safety belt 16 includes a first, or shoulder, belt strap 18 and a second, or lap, belt strap 20. The shoulder belt 18 is paid out from a first retractor 22, and the lap belt 20 is paid out from a second retractor 24. More specifically, an occupant can extend the safety belt 16 from the first and second retractors 22 and 24 until the safety belt 16 is a suitable length for buckling. In other systems, only the first retractor 22 may be present and the end of the lap belt 20 may be attached to the vehicle or seat structure (not shown). The occupant can secure the safety belt 16 by inserting a locking plate or tongue 26 of the safety belt 16 into a buckle 28. The occupant can release the safety belt 16 by pressing a button 30 on the belt buckle 28 or unbuckle the safety belt 16.The first and second retractors 22 and 24 can then retract the seat belt 16. The first and second retractors 22 and 24 can be attached to the vehicle structure within the interior 12 and / or to the seat 14.

[0037] The shoulder belt 18 and the lap belt 20 are fastened to each other and to the tongue 26. The tongue 26 can, for example, be sewn into the lap belt 20 and the shoulder belt 18. Alternatively, the tongue 26 can be sewn into the lap belt 20 and the shoulder belt 18 can be mechanically fastened to the tongue 26. The shoulder belt 18 is guided through a guide loop 31 attached to the vehicle or body structure and optionally through a routing guide 17 on the seat 14. The routing guide 17 can permanently encapsulate the shoulder belt 18 or temporarily encapsulate it if the shoulder belt 18 can be removed from the routing guide 17. The vertical position of the guide loop 31 can be adjustable to accommodate different shoulder heights of the occupant.

[0038] In another approach, the second retractor 24 is omitted, and a single strap is slidably guided through the tongue 26. The portion of the strap between the tongue and the first retractor 22 is the shoulder strap 18. The other portion of the belt is the lap belt 20. The length of the shoulder strap 18 and the lap belt 20 changes depending on the slidable position of the tongue 26.

[0039] The buckle 28 can be in a closed or an unlocked position. When the buckle 28 is in a closed position, a locking member (not shown) within the buckle 28 engages the tongue 26 to secure the tongue 26 within the buckle 28. When the belt button 30 is pressed, the locking member releases the tongue 26, and a spring-loaded ejector mechanism (not shown) urges the locking member into the unlocked position. The locking member remains in the unlocked position until the tongue 26 is inserted into the buckle 28, forcing the locking member into the closed position to secure the tongue 26.

[0040] A buckle sensor 32, which may be a buckle switch, detects whether the tongue 26 of the seat belt 16 is secured in the buckle 28 based on the position of the spring-loaded ejector mechanism or the tongue 26 of the seat belt 16. Alternatively, the buckle sensor 32 may detect whether the belt button 30 is pressed. The buckle sensor 32 may be a Hall-effect sensor that changes its voltage output in response to a magnetic field. The buckle sensor 32 generates a buckle status signal (BS) that indicates whether the tongue 26 of the seat belt 16 is secured in the buckle 28 and / or whether the belt button 30 is pressed. The buckle sensor 32 may alternatively be a reed switch, mechanical sensor, or other sensor or switch that detects whether the tongue 26 is secured in the buckle 28.

[0041] The first retractor 22 may be an automatic locking retractor. Thus, the first retractor 22 may include a first spool attached to a first control disk (not shown). When the occupant pulls the shoulder belt 18 of the safety belt 16 out of the first retractor 22 to a first predetermined length at or near full extension, a first pawl (not shown) engages the first control disk to prevent rotation of the first spool and the first control disk in the direction of extension of the shoulder belt 18. However, engagement of the first pawl with the first control disk does not prevent retraction of the shoulder belt 18. As long as the first retractor 22 is not deactivated (i.e.Thus, when the shoulder strap 18 is retracted to a second predetermined length to disengage the first pawl from the first control disc, the control disc and the first spool can only rotate in one direction, and the shoulder strap 18 can tighten (i.e., retract) but not loosen (i.e., extend). This function is used to secure child seats to the vehicle via the safety belt 16.

[0042] The second retractor 24, if present, may be similar to the first retractor 22 and may also be an automatic locking retractor. More specifically, the second retractor 24 may include a second spool attached to a second control pulley (not shown). When the occupant pulls the lap belt 20 of the safety belt 16 out of the second retractor 24 to the first predetermined length, a second pawl (not shown) engages the second control pulley to prevent rotation of the second spool and the second control pulley in the direction of pulling out the lap belt 20. However, the engagement of the second pawl with the second control pulley does not prevent retraction of the lap belt 20. As long as the second retractor 24 is not deactivated (i.e.(i.e., the lap belt 20 is retracted to the second predetermined length to release the second pawl from the second control disc), the second control disc and the second spool can only rotate in one direction, and the lap belt 20 can tighten (i.e., retract) but not loosen (i.e., extend). Although the first and second retractors 22 and 24 are described as auto-locking retractors, the first and second retractors 22 and 24 may, in various designs, not be auto-locking retractors. If the first and second retractors 22 and 24 are not auto-locking retractors, they can pay out and retract the safety belt 16 without performing the function of securing a child restraint seat.

[0043] The occupant typically deactivates the first retractor 22 by retracting the shoulder belt 18 into the first retractor 22 to the second predetermined length. Retracting the shoulder belt 18 to the second predetermined length may involve retracting a significant portion of the shoulder belt 18 into the first retractor 22. In one example, retracting the shoulder belt 18 into the first retractor 22 involves retracting almost all of the shoulder belt 18 into the first retractor 22. The occupant may similarly deactivate the second retractor 24 by retracting the lap belt 20 into the second retractor 24 to the second predetermined length. When the occupant retracts the shoulder belt 18 or the lap belt 20 to the second predetermined length, the respective first or second pawl disengages from the respective first or second control disc.Retracting the respective belt webbing 18, 20 to the second predetermined length allows the first or second control disc and the respective first or second spool to rotate freely in either direction. The occupant can then use the seat belt 16 normally or engage one or both of the first and second retractors 22 and 24 by extending the respective belt webbing 18 and 20 to the first predetermined length.

[0044] The first retractor 22 includes a first or shoulder belt sensor 33. The shoulder belt sensor 33 generates a shoulder belt extension (SWP) signal indicating shoulder belt extension. The shoulder belt webbing extension corresponds to a length of the shoulder belt 18 of the safety belt 16 output from the first retractor 22. The second retractor 24, if present, includes a second or lap belt extension sensor 34. The lap belt extension sensor 34 generates a lap belt extension (LWP) signal indicating lap belt extension. The lap belt webbing extension corresponds to a length of the lap belt 20 of the safety belt 16 output from the second retractor 24. In the event that only a first retractor 22 is present, the SWP signal may indicate the combined shoulder belt and lap belt extension.

[0045] The outputs of the shoulder and lap belt extension sensors 33 and 34 are inputs to a body control module (BCM) 50. The BCM 50 can determine the path of the seat belt 16 using the SWP signal and the LWP signal and thus identify when the seat belt 16 is improperly fastened. Incorrect fastening of the seat belt 16 can be referred to as a belt failure. For example, the BCM 50 can store a relationship between webbing extension and belt path and determine the belt path based on the SWP and LWP signals using the stored relationship. In the event that only the retractor 22 is present, the BCM 50 can use the SWP signal to determine the path of the seat belt 16 without using an LWP signal.

[0046] The BCM 50 may control a user interface device 54 in the interior 12 of the vehicle, such as an audible warning signal, an electronic display, or tactile feedback, to display a message indicating the presence of a seat belt failure. For example, the BCM 50 controls the user interface device 54 to generate a visual message (e.g., text, a light, and / or an icon), an audible message (e.g., a chime), and / or a tactile message (e.g., a vibration) indicating the presence of a seat belt failure. The BCM 50 may determine whether the belt failure exists based on the SWP signal and, if present, the LWP signal. The occupant may interact with the user interface device 54 to acknowledge the message. In this case, the BCM 50 may deactivate (e.g., no longer generate) the message.

[0047] The BCM 50 may also control the speed of the vehicle based on whether the seat belt failure is present. The BCM 50 may also control the speed of the vehicle by sending a vehicle speed command to at least one of an engine control module (ECM) 51, a transmission control module (TCM) 52, and / or an electronic brake control module (EBCM) 53. The ECM 51 controls an engine (not shown). The TCM 52 controls the operation of a transmission (not shown). The TCM 52 may control gear selection within the transmission and one or more torque-transmitting devices (e.g., a torque converter, one or more clutches, etc.) (not shown). The EBCM 53 selectively controls electronically controlled friction brakes (not shown) of the vehicle.

[0048] The vehicle system 10 also includes a vehicle speed sensor 55 that measures the speed of the vehicle. The ECM 51, the TCM 52, and / or the EBCM 53 may control the speed of the vehicle based on the measured vehicle speed using a closed-loop control system. The vehicle speed sensor 55 may output the measured vehicle speed to the BCM 50, and the BCM 50 may relay the measured vehicle speed to the ECM 51, the TCM 52, and / or the EBCM 53. Alternatively, the vehicle speed sensor 55 may output the measured vehicle speed directly to the ECM 51, the TCM 52, and / or the EBCM 53.

[0049] The BCM 50, the ECM 51, the TCM 52, and / or the EBCM 53 may determine the acceleration of the vehicle by integrating the measured vehicle speed over time. Additionally or alternatively, the vehicle system 10 may include a vehicle accelerometer 49 that measures the acceleration of the vehicle. The vehicle accelerometer 49 may generate a vehicle acceleration (VA) signal indicative of the measured vehicle acceleration and output the VA signal to the BCM 50.

[0050] The vehicle system 10 also includes one or more interior sensors 57. The interior sensors 57 may include sensors such as a camera, an infrared sensor, an ultrasonic sensor, a radar sensor, a lidar sensor, or a combination thereof. In one example, the interior sensors 57 are cameras, the vehicle includes multiple seats 14, and the vehicle includes an interior sensor 57 for each seat 14. Each camera is capable of generating an image of the seat 14, the seatbelt 16, and an occupant in the seat 14. The interior sensors 57 may alternatively cover more than one vehicle seating location. Furthermore, multiple interior sensors 57 may be used for one seating location. Additionally, more than one sensor technology may be used, and the BCM 50 may combine the information from each interior sensor 57.

[0051] The interior sensor 57 may capture images continuously or periodically at specific times (e.g., before, during, or after a trip). An output of the interior sensor 57 may be an input to the BCM 50. For example, the BCM 50 may detect edges of the seat belt 16, the surface of the seat belt 16, and / or an object in the seat 14 in an image from the interior sensor 57. The seat belt 16 may have various markings or embedded material that can be detected by the interior sensors 57 to distinguish the seat belt 16 from its surroundings. The BCM 50 may determine the path of the seat belt 16 in two- or three-dimensional space based on the detected edges or surfaces of the seat belt 16. The BCM 50 may use the detected edges of an object in the seat 14 to detect the presence of an occupant and / or a child restraint seat in the seat 14.The BCM 50 may also use inputs from the interior sensors 57 to detect the occupant's size and position. The BCM 50 may use the occupant's size and position to adjust the stored relationship between belt webbing extension and belt path.

[0052] The BCM 50 may use inputs from the buckle sensor 32, the belt retraction sensor(s) 33 (and 34, if equipped), and the interior sensors 57 to determine whether an occupant in the seat 14 has properly fastened the seat belt 16. Each of the buckle sensor 32, the belt retraction sensor(s) 33 (and 34, if equipped), and the interior sensors 57 have unique strengths and weaknesses. In this way, the BCM 50 may more accurately and robustly determine whether the seat belt 16 is properly fastened by using inputs from all three sensor types, rather than using inputs from only one of the three types.

[0053] The strengths of the buckle sensor 32 include low power consumption and the ability to detect whether the seat belt 16 is fastened. The weakness of the buckle sensor 32 is that its output cannot be used to determine belt path. The strengths of the belt extension sensor(s) 33 (and 34, if present) include low power consumption and the ability to detect the extension of the shoulder and lap belts 18 and 20. Furthermore, the belt webbing extension detected by the belt extension sensor(s) 33 (and 34, if present) can be used to determine belt path under most conditions.

[0054] Weaknesses of the belt retraction sensor(s) 33 (and 34, if present) include the inability to detect whether the safety belt 16 is buckled. Furthermore, it is difficult to detect when the safety belt 16 is routed under an occupant's arm using the output of the belt retraction sensor(s) 33 (and 34, if present). Furthermore, it is difficult to distinguish whether the safety belt 16 is routed around a child restraint seat or around a small, forward-facing child based on the output of the belt retraction sensors 33 (and 34, if present).Finally, it is difficult to determine from the output of the belt extension sensor(s) 33 (and 34, if present) whether the safety belt 16 is routed through the routing guide 17, over or through the routing guides formed by the belt guide wings in the case of a backless booster child restraint seat, or through fully enclosed routing guides in the case of other types of child restraint seats.

[0055] The strengths of the interior sensors 57 include the ability to distinguish between different shoulder and lap belt paths based on the output of the interior sensors 57. In addition, the output of the interior sensors 57 can be used to detect the presence of a child restraint seat in the seat 14. In addition, the output of the interior sensors 57 can be used to detect when the shoulder or lap belt 18 or 20 is twisted or when the shoulder belt 18 passes through the routing guide 17. In addition, the output of the interior sensors 57 can be used to detect whether the lap belt webbing 20 passes over or through the routing guides formed by the webbing guide wings on a backless booster seat or through fully enclosed webbing routing guides on a child restraint seat, if these are visible to the interior sensors 57.

[0056] The weaknesses of the interior sensors 57 include high power consumption, the potential need for power-hungry interior lighting, and the inability to detect whether the seat belt 16 is fastened. Furthermore, it is difficult to determine the belt path from the output of the interior sensor 57 if the seat belt 16 is covered or hidden from the field of view of the interior sensors 57. Furthermore, the output of the interior sensors 57 may be affected by lighting conditions.

[0057] The BCM 50 can utilize the aforementioned strengths of the buckle sensor 32, the belt extension sensor(s) 33 (and 34, if present), and the interior sensors 57 while avoiding the aforementioned weaknesses of the sensors. For example, the BCM 50 can continuously monitor the output of the buckle sensor 32 because the buckle sensor 32 has low power consumption. Furthermore, the BCM 50 can continuously or periodically monitor the output of the belt extension sensor(s) 33 (and 34, if present). Furthermore, the BCM 50 only needs to monitor the interior sensors 57 periodically because the interior sensors 57 have high power consumption.

[0058] In one example, the BCM 50 turns on or activates the interior sensors 57 only when the belt webbing extensions measured by the belt extension sensor(s) 33 (and 34, if present) change by an amount greater than a threshold (e.g., a predetermined value or delta value). At this time, the BCM 50 uses the interior sensors 57 to determine the belt path and, if necessary, adjusts the stored relationship between belt webbing extension and belt path based on the determined belt path. The BCM 50 can then turn off or deactivate the interior sensors 57 and accurately determine the seat belt path based solely on the inputs from the belt extension sensor(s) 33 (and 34, if present). In various implementations, the BCM 50 can leave the interior sensors 57 constantly turned on or activated (e.g.,whenever the vehicle's ignition is switched on) if the power consumption of the interior sensors 57 and the associated lights is acceptable.

[0059] The vehicle system 10 may also include an occupant sensing device 58, such as a weighted pad. The weighted pad may measure the weight of objects or people in the seat 14. The occupant sensing device 58 may alternatively include pressure sensors, ohmmeters, capacitive sensors, electric field proximity sensors, biometric sensors, and / or other types of sensors. Weight, pressure, resistance, capacitive, electric field, and biometric sensor systems are typically located inside the seat 14. However, they may also be located outside the seat 14 and communicate with the seat 14, e.g., by being integrated into a seat-to-body attachment structure. Additionally, one or more interior sensors 57 may be used to provide and evaluate images of occupants, and thus the interior sensors 57 may be an occupant sensing device.An output of the occupant sensing device 58 is an input to the BCM 50. The BCM 50 need not instruct the ECM 51, the TCM 52, and the EBCM 53 to adjust the speed of the vehicle based on the first or lap belt extension if the occupant sensing device 58 indicates that the seat 14 is unoccupied.

[0060] The BS signal is also an input to the BCM 50. The BCM 50 detects that the tongue 26 of the seat belt 16 is disengaged from or connected to the buckle 28 based on the BS signal and / or the input from the occupant sensing device 58. The BCM 50 need not command the ECM 51, the TCM 52, and / or the EBCM 53 to adjust the vehicle speed if the BS signal indicates that the tongue 26 of the seat belt 16 is disengaged from the buckle 28 of the seat belt 16 or the occupant sensing device indicates that no occupant is present. Additionally or alternatively, the BCM 50 may instruct the ECM 51, the TCM 52, and / or the EBCM 53 to adjust the speed of the vehicle when the BS signal indicates that the tongue 26 of the seat belt 16 is disengaged from the buckle 28 of the seat belt 16 when the occupant sensing device 58 or the interior sensor 57 indicates that the occupant is present.

[0061] The vehicle system 10 also includes a seatback position sensor 59 and a seat bottom position sensor 60. The seatback position sensor 59 is located on a backrest 62 of the seat 14, and the seat bottom position sensor 60 is located on a bottom surface 64 of the seat 14. The outputs of the seatback position sensor 59 and the seat bottom position sensor 60 are inputs to the BCM 50. The seatback position sensor 59 generates a seatback position (BKP) signal indicative of an angle of the seatback 62 relative to the seat bottom 64. The seat bottom position sensor 60 generates a seat bottom position (BMP) signal indicative of a fore-aft or fore-aft position of the seat bottom 64 relative to the second retractor 24 or a specific location on a body of the vehicle. The BMP signal may also indicate a vertical position of the seat surface 64 and / or an angle of the seat surface 64 relative to a horizontal plane.

[0062] In one example, the seatback position sensor 59 and the seat bottom position sensor 60 are discrete position switches that detect the seat position relative to a specific location on the vehicle body. In another example, the seatback position sensor 59 and the seat bottom position sensor 60 continuously provide position information. The BCM 50 can set belt length thresholds based on the BKP signal and the BMP signal, which are used to detect whether the seat belt is properly fastened.

[0063] In addition to or instead of using the seat position sensors 59, 60 to determine the seat position, the BCM 50 may use the interior sensor 57 to determine the seat position. For example, the BCM 50 may detect edges of the seat back 62 and the seat bottom 64 or portions of surfaces of the seat back 62 and the seat bottom 64 in an image from the interior sensor 57. The BCM 50 may determine the positions and angles of the edges or surfaces based on a predetermined relationship between positions and angles in the image and positions and angles of edges in a predetermined seat position profile. The BCM 50 determines the seat position based on a comparison between the image and the predetermined seat position profile.

[0064] The vehicle system 10 also includes a guide loop position sensor 61. The guide loop position sensor 61 is located on, in, or near the guide loop 31. The outputs of the guide loop position sensor 61 are an input to the BCM 50. The guide loop position sensor 61 generates a guide loop position (GLP) signal indicative of a position (e.g., the vertical position) of the guide loop 31 relative to the seat back 62 and / or a discrete point on a body of the vehicle.

[0065] Additionally or alternatively, the BCM 50 may use the output of the interior sensor 57 to determine the guide loop position. For example, the BCM 50 may detect edges of the guide loop 31 or portions of surfaces of the guide loop 31 in an image from the interior sensor 57. The BCM 50 may determine the positions and angles of the edges or surfaces based on a predetermined relationship between positions and angles in the image and positions and angles of edges in a predetermined position profile of the guide loop. The BCM 50 determines the seat position relative to the first retractor 22 (and the second retractor 24, if present) based on a comparison between the image and the predetermined seat position profile.

[0066] The vehicle system 10 further includes a first pawl sensor 66 and, if the second retractor 24 is present, a second pawl sensor 68. The first pawl sensor 66 detects a position of the first pawl, indicating whether the first pawl is engaged with the first control disc of the first retractor 22. If present, the second pawl sensor 68 detects a position of the second pawl, indicating whether the second pawl is engaged with the second control disc of the second retractor 24. The first pawl sensor 66 generates a first pawl sensor signal (RS1), and the second pawl sensor 68 generates a second pawl sensor signal (RS2). The RS1 signal and the RS2 signal are inputs to the BCM 50.

[0067] The BCM 50 may also generate a signal or control the user interface device 54 to display a message indicating that an automatic locking retractor (ALR) usage error has occurred. The ALR usage error may occur when one or both of the first and second retractors 22 and 24 are disengaged when they should be engaged (e.g., when a child restraint seat is present in the seat 14), or when one or both of the first and second retractors 22 and 24 are engaged when they should be disengaged (e.g., when the occupant is sitting in the seat 14 without a child restraint seat). The BCM 50 determines whether the ALR usage error has occurred based on the RS1 signal and the RS2 signal.

[0068] The BCM 50 can control a speed of the vehicle based on the RS1 signal and the RS2 signal. For example, the BCM 50 determines that the ALR usage error exists when either the first retractor 22 or the second retractor 24 is engaged (i.e., the first or second pawl is engaged with the respective first or second control disc) and the other of the first retractor 22 and the second retractor 24 is disengaged (i.e., the first or second pawl is disengaged from the respective first or second control disc). The BCM 50 issues a warning, reduces the speed of the vehicle, or prevents the vehicle from moving when the ALR usage error is detected.Alternatively, as another example, the BCM 50 determines that the ALR usage error exists if the first retractor 22 is engaged while a large occupant is in the seat, or if the first retractor 22 is not engaged while a child restraint seat is present.

[0069] The vehicle system 10 may also include one or more LATCH (lower anchor and tethers for children) sensors (not shown). The LATCH sensors detect whether clips of a child restraint seat are coupled to lower and / or upper anchors of the vehicle seat 14. The LATCH sensors may be located near or integrated with the lower and / or upper anchors.

[0070] The vehicle system 10 may also include one or more seat belt proximity sensors (not shown). The belt proximity sensors detect the proximity of the seat belt 16 to the sensors using one or more RFID (Radio Frequency Identification) tags attached to the seat belt 16. The BCM 50 may use the inputs from the belt proximity sensors to determine the routing of the seat belt 16.

[0071] In Fig. 2 shows an example implementation of the BCM 50, a seat position module 82, an occupant detection module 84, an occupant posture module 86, a sensor condition module 88, a seat belt routing module 90, and a user interface device (UID) control module 92. The seat position module 82 determines the position of the seat 14. The seat position module 82 may determine the fore-aft or fore-aft position of the seat bottom 64, the vertical position of the seat bottom 64, the angle of the seat bottom 64, and / or the angle of the seat back 62 relative to the seat bottom 64.

[0072] The seat position module 82 may determine the angle of the seatback 62 relative to the seat bottom 64 based on the BKP signal from the seatback position sensor 59. The seat position module 82 may determine the fore-aft or longitudinal position of the seat bottom 64 relative to the second retractor 24 or a specific location on the vehicle body based on the BMP signal from the seat bottom position sensor 60. Additionally or alternatively, the seat position module 82 may use the BMP signal to determine the vertical position of the seat bottom 64 relative to the floor of the vehicle body and / or the angle of the seat bottom 64 relative to a horizontal plane.

[0073] In addition to or instead of using the seat position sensors 59, 60 to determine the seat position, the seat position module 82 may use the interior sensor 57 to determine the seat position. For example, the seat position module 82 may detect edges of the seat back 62 and the seat bottom 64 or portions of surfaces of the seat back 62 and the seat bottom 64 in an image from the interior sensor 57. The seat position module 82 may determine the positions and angles of the edges or surfaces based on a predetermined relationship between positions and angles in the image and positions and angles of edges in a predetermined seat position profile. The seat position module 82 may determine the seat position based on a comparison between the image and the predetermined seat position profile.

[0074] The occupant detection module 84 detects whether an occupant, a child restraint seat, or another object is located in the seat 14. The occupant detection module 84 may detect whether an occupant, a child restraint seat, or another object is located in the seat 14 based on input from the occupant detection device 58. Additionally or alternatively, the occupant detection module 84 may detect whether an occupant, a child restraint seat, or another object is located on the seat 14 based on input from the interior sensor 57. The occupant detection module 84 may be capable of distinguishing between an occupant, a child restraint seat, and another object, as well as determining a child restraint seat type and occupant size. Additionally, the occupant detection module 84 may detect belt paths on or through child restraint seats if they are visible to the interior sensor 57.

[0075] In one example, the occupant detection module 84 detects the edges of an object on the seat 14 in an image from the interior sensors 57, and the occupant detection module 84 uses the edges to determine the size, shape, and / or position of the object. The occupant detection module 84 may determine that the object is an occupant if the size of the object falls within a predetermined occupant size range and / or the shape of the object matches a predetermined occupant shape. Additionally or alternatively, the occupant detection module 84 may determine that the object is an occupant if the position of the object matches a predetermined occupant position.

[0076] The occupant posture module 86 determines the posture of an occupant in the seat 14 based on inputs from the interior sensor 57. For example, the occupant posture module 86 may detect edges of objects in the image captured by the interior sensors 57 and use these edges to identify the shape, size, and / or relative position of the objects. The occupant posture module 86 may then determine, based on the shape, size, and / or relative positions of the objects, whether these objects correspond to certain skeletal features (e.g., head, neck, shoulder, spine, arms, legs) or facial features (e.g., eye, nose, chin, mouth, ear).For example, the occupant posture module 86 may determine that an object is a particular skeletal feature of an occupant in the seat 14 if the object's shape matches a predetermined shape window, the object's size matches a predetermined size range, and / or the object's location matches a predetermined location range. The occupant posture module 86 may store a predetermined shape window, a predetermined size range, and a predetermined location range for each type of skeletal or facial feature identified in the image.

[0077] Once the occupant posture module 86 has identified the skeletal features of an occupant in the seat 14, the occupant posture module 86 may determine the occupant's posture based on the size and relative location of those features. For example, the occupant posture module 86 may determine the occupant's height based on the size of the skeletal features or the location of the facial features and then assess the occupant's posture based on the occupant's height and one or more distances between the skeletal features or the distances of the facial features from the seat surface. In one example, the occupant posture module 86 determines that the occupant's posture is not upright (e.g., the occupant is slouching) when the distance between the occupant's head and waist or thighs is less than a predetermined distance.

[0078] The sensor condition module 88 wakes or activates the shoulder belt retraction sensor 33, the lap belt retraction sensor 34 (if present), and / or the interior sensor 57 at certain times to monitor the path of the seat belt 16. The sensor condition module 88 may wake the shoulder belt retraction sensor 33, the lap belt retraction sensor 34 (if present), and / or the interior sensor 57 by connecting a power supply (not shown) thereto. The sensor condition module 88 sleeps or deactivates the shoulder belt retraction sensor 33, the lap belt retraction sensor 34 (if present), and / or the interior sensor 57 at other times to conserve power. The sensor condition module 88 may sleep the shoulder belt retraction sensor 33, the lap belt retraction sensor 34 (if present), and / or the interior sensor 57 by removing power to them.

[0079] The belt path module 90 determines the path of the seat belt 16 based on inputs from the shoulder belt extension sensor 33, the lap belt extension sensor 34 (if present), and the interior sensor 57. The belt path module 90 may store a relationship between webbing extensions and the seat belt path and determine the seat belt path in a one-dimensional space based on the inputs from the belt extension sensor(s) 33 (and 34, if present) using the stored relationship. For example, the belt path module 90 may identify a particular belt path when the webbing extensions correspond to predetermined ranges over time-based corridors for that belt path. The belt path module 90 may adjust the stored relationship between webbing extensions and belt path to account for various factors that may affect this relationship.These factors may include: an occupant in the vehicle seat 14 assuming a non-upright posture, the occurrence of a rapid stop, an occupant in the vehicle seat 14 refastening a seat belt 16, a child seat in the vehicle seat 14, the vehicle seat 14 being moved, and / or the guide loop 31 being moved.

[0080] The belt path module 90 may store a unique belt webbing extension range or a time-extraction history corridor or characteristic for each possible seat belt path. Alternatively, the belt webbing extension ranges for the possible belt paths may overlap, and the belt path module 90 may determine that the measured belt webbing extensions correspond to more than one belt path. In this latter case, the belt path module 90 may assign a confidence to each of the possible seat belt paths. The possible shoulder belt paths are: across the chest and over the shoulder, across the chest and away from the shoulder, across the chest and under the arm, on the wrong side of the head and down the chest to the buckle, and behind the back. The possible belt webbing paths are over the lap or waist and under the lap. Other possible belt paths are that the seat belt 16 is stowed (i.e.into the first retractor 22 and, if present, into the second retractor 24) and that the safety belt 16 is correctly or incorrectly guided around a child seat.

[0081] The belt routing module 90 also determines the routing of the seat belt 16 based on the inputs from the interior sensors 57. In one example, the belt routing module 90 detects edges or surfaces of objects within the fields of view of the interior sensors 57 and determines the size, shape, and position of those objects based on the detected edges and surfaces. The belt routing module 90 then determines, based on the size, shape, and location of the objects, whether one or more of the objects correspond to the shoulder belt 18 and / or the lap belt 20. For example, the belt routing module 90 may determine that an object in the image is the shoulder belt webbing 18 if the size of the object corresponds to a predetermined size range, the shape of the object corresponds to a predetermined shape window, and the location of the object corresponds to a predetermined location range.As another example, the belt routing module 90 may detect the presence of the routing guide 17 and determine whether the shoulder belt webbing 18 passes through it. In another example, the belt routing module 90 may detect whether the shoulder belt webbing 18 and the lap belt webbing 20 have traversed a detected routing path in a child restraint seat.

[0082] If the belt routing module 90 determines that an object in the image coincides with the shoulder belt 18 and / or the lap belt 20, the belt routing module 90 then uses the edges or surfaces of the object to assess the belt routing. In assessing the belt routing, the belt routing module 90 may also use the location of skeletal or facial features of the occupant, as determined by the occupant posture module 86, and / or the location of the shoulder belt 18 and / or the lap belt 20 passing through locations on a child restraint seat, as determined by the occupant detection module 84. For example, the belt routing module 90 may determine whether the seat belt 16 is routed over the shoulder, away from the shoulder, or under the arm based on the relative positions of the seat belt 16 and the shoulder or arm.As another example, the belt routing module 90 may determine whether the safety belt 16 is routed through a grommet or a guide loop on a child seat.

[0083] The belt routing module 90 may, under certain conditions, use the belt retraction sensor(s) 33 (and 34, if present) as the primary sensor for determining the belt routing. Under these conditions, the belt routing module 90 may use the interior sensor 57 as the secondary sensor to confirm or verify the belt routing determined by the belt retraction sensor(s) 33 (and 34, if present). The belt routing module 90 may, under other conditions, use the interior sensor 57 as the primary sensor for determining the belt routing. Under these other conditions, the belt routing module 90 may use the belt retraction sensor(s) 33 (and 34, if present) as the secondary sensor(s) to confirm or verify the belt routing determined by the interior sensor 57.

[0084] The UID control module 92 controls the user interface device 54 to alert an occupant in the cabin 12 or personnel monitoring the ride outside the vehicle when the seat belt 16 is not properly routed. The UID control module 92 may also control the user interface device 54 to alert the occupant or personnel monitoring the ride outside the vehicle of other conditions, such as excessive extension of the seat belt 16 when the seat belt 16 is stowed. The vehicle speed control module 94 may send a vehicle speed command to the ECM 51, the TCM 52, and / or the EBCM 53 to reduce the vehicle speed when the seat belt 16 is not properly routed.

[0085] According to Fig. 3, at 102, a method begins for monitoring the routing of the seat belt 16 based on inputs from both the belt retraction sensor(s) 33 (and 34, if present) and the interior sensor 57. At 104, the belt routing module 90 determines whether a trip has been initiated. For example, the belt routing module 90 may determine that a trip has been initiated if the vehicle doors are closed, an ignition switch is in an on or start position, an ignition button is pressed, and / or a drive command is given. The belt routing module 90 may determine when the vehicle doors are closed based on input from door position sensors (not shown). The belt routing module 90 may determine when an ignition switch or button is in an on position based on an ignition switch position sensor (not shown).The belt routing module 90 may determine when a drive command has been issued from a drive status sensor (not shown). If a drive has been initiated, the method continues at 106. Otherwise, the belt routing module 90 continues to determine whether a drive has been initiated.

[0086] At 106, the shoulder belt extension sensor 33 and the lap belt extension sensor 34 (if present) monitor the shoulder and lap belt extensions, respectively (e.g., by repeated measurement). At 108, the buckle sensor 32 monitors the state of the buckle of the safety belt 16 (e.g., by repeated detection). In other words, the buckle sensor 32 monitors whether the safety belt 16 is closed or open.

[0087] At 110, the sensor condition module 88 determines whether a change in shoulder and / or lap belt extension is greater than a first delta value. The first delta value may be a first predetermined difference between the current webbing extension and a stored length of the safety belt 16 at its minimum extension length when the safety belt 16 is first worn by an occupant or when the safety belt 16 is first wrapped around a child restraint seat. If the webbing extension change is greater than the first delta value, the method continues at 112. Otherwise, the method returns to 104.

[0088] At 112, the sensor condition module 88 determines whether the buckle state of the safety belt 16 has changed from unfastened to fastened. If the buckle state of the safety belt 16 has changed to fastened, the method continues at 114. Otherwise, the method returns to 104.

[0089] At 114, the sensor condition module 88 wakes up the interior sensors 57. At 116, the belt path module 90 monitors the belt path using the interior sensors 57. At 118, the belt path module 90 determines whether the belt path determined using the interior sensors 57 matches the belt path determined from the belt extensions or belt extension time histories measured by the belt extension sensor(s) 33 (and 34, if used). In one example, the belt path may be more accurately detected by the interior sensors 57 than by the belt extension sensor(s) 33 (and 34, if used). In this case, the belt path module 90 identifies a plurality of possible seat belt paths based on the belt extensions or belt extension time histories.If the belt path determined with the interior sensors 57 corresponds to one of the possible belt paths, the belt path determined with the interior sensors 57 confirms the belt path determined from the belt webbing extensions or belt webbing extension time histories measured by the belt extension sensor(s) 33 (and 34, if used). If the belt path determined with the interior sensors 57 confirms the belt path determined from the belt webbing extensions or belt webbing extension time histories, the method continues at 120. Otherwise, the method continues at 122. At 120, the belt path module 90 stores the belt path determined with the interior sensors 57 as the current belt path, and the method continues at 130.

[0090] At 122, the belt path module 90 determines whether the belt path determined from the webbing extensions or webbing extension time histories measured by the belt extension sensor(s) 33 (and 34, if used) confirms the belt path determined by the interior sensors 57. In one example, the belt path may be more accurately detected by the interior sensors 57 than by the belt extension sensor(s) 33 (and 34, if used). In this case, the belt path module 90 determines the belt path based on the webbing extensions measured by the belt extension sensor(s) 33 (and 34, if used) and identifies a plurality of possible belt paths based on the input from the interior sensors 57.If the belt path determined by the belt extension sensor(s) 33 (and 34, if present) corresponds to one of the possible belt paths, the belt path determined from the belt extensions or belt extension time histories measured by the belt extension sensor(s) 33 (and 34, if present) confirms the belt path determined by the interior sensors 57. If the belt extensions measured by the belt extension sensor(s) 33 (and 34, if present) confirm the belt path determined by the interior sensors 57, the method continues at 124. Otherwise, the method continues at 126. At 124, the belt path module 90 stores the belt path determined by the belt extension sensor(s) 33 (and 34, if present) as the current belt path, and the method continues at 130.

[0091] At 126, the belt path module 90 selects either the belt retraction sensor(s) 33 (and 34, if present) or the interior sensors 57 as the primary sensors for determining the belt path. The belt path module 90 may make the selection based on the belt path(s) determined using the belt retraction sensor(s) 33 (and 34, if present) and / or the interior sensors 57. For each sensor type, a confidence level for a determined belt path may be calculated, and the sensor type with the highest confidence level may be selected, as described in connection with the methods of Fig. 5A and Fig. 5B. Additionally or alternatively, the belt path module 90 may make the selection dependent on whether the field of view of the interior sensors 57 is partially or completely obstructed or hidden. The belt path module 90 stores the belt path determined using any of (i) belt retraction sensor(s) 33 (and 34, if present) and (ii) the interior sensors 57 selected as primary sensors.

[0092] In one example, the belt routing module 90 selects the belt extension sensor(s) 33 (and 34, if present) as the primary sensors for determining the routing of the lap belt 20 in any condition. In another example, the belt routing module 90 selects the belt extension sensor(s) 33 (and 34, if present) as the primary sensor(s) for determining the routing of the shoulder belt 18 when the field of view of the interior sensors 57 is partially or completely obscured. In another example, the belt routing module 90 selects the belt extension sensor(s) 33 (and 34, if present) as the primary sensors for determining the routing of the shoulder belt 18 when the interior sensors 57 are in the idle state.

[0093] In another example, the belt routing module 90 selects the interior sensors 57 as the primary sensors for determining the shoulder belt routing when the belt extension sensor(s) 33 (and 34, if present) indicate that one of multiple shoulder belt paths is possible and the shoulder belt paths cannot be reliably distinguished from one another using the belt extension sensor(s) 33 (and 34, if present). The multiple shoulder belt paths include: across the chest and over the shoulder, across the chest and away from the shoulder (e.g., to one side of the shoulder), on the wrong side of the head and down the chest to the buckle, and across the chest and under the arm. In another example, the belt routing module 90 selects the interior sensors 57 as the primary sensors for determining the time at which to store the relationship between the webbing extension and the belt guide, e.g.,when the safety belt 16 has reached its minimum extension length, when worn by an occupant, or when routed around a child restraint seat. In another example, the belt routing module 90 selects the interior sensors 57 as the primary sensors to determine whether the safety belt 16 has routed through the routing guide 17 or passed through a detected routing path or slot in a child restraint seat.

[0094] In another example, the belt routing module 90 selects the interior sensors 57 as primary sensors to confirm that additional slack has been introduced, for example, by the shoulder belt webbing 18 being clipped to the interior panel or the vehicle structure, by the safety belt 16 being held away from the body with a hand, or by an object being placed between the body and the safety belt 16. In another example, the belt routing module 90 selects the interior sensors 57 as primary sensors to determine whether the safety belt 16 is routed over routing guides of a child restraint seat rather than through the routing guides. In another example, the belt routing module 90 selects the interior sensors 57 as primary sensors for determining shoulder belt routing when the body posture of an occupant in the seat 14 is not upright.

[0095] In another example, the belt path module 90 selects the interior sensors 57 as the primary sensors for confirming that the seat belt 16 has been manually tightened by an occupant in the cabin 12. In another example, the belt path module 90 selects the interior sensors 57 as the primary sensors for determining belt path, which are used to adjust the stored relationship between webbing extension and belt path after a rapid braking event. In another example, the belt path module 90 selects the interior sensors 57 as the primary sensors for confirming that the seat belt 16 is properly stowed.

[0096] At 128, the belt path module 90 adjusts a belt path classification of one or more secondary sensors used by the belt path module 90 to determine belt path. The secondary sensors may be (i) the belt extension sensor(s) 33 (and 34, if present) and (ii) the interior sensors 57 that are not selected as primary sensors. For example, if the belt path module 90 selects the belt extension sensor(s) 33 (and 34, if present) as the primary sensor(s), the interior sensors 57 may be the secondary sensors. In another example, if the belt path module 90 selects the interior sensors 57 as the primary sensors, the belt extension sensor 33 (and 34, if present) may be the secondary sensor(s).

[0097] The belt path classification may be a relationship between the inputs from the secondary sensors and the belt path. For example, if the belt extension sensor(s) 33 (and 34, if present) are the secondary sensors, the belt path classification of the belt extension sensor(s) 33 (and 34, if present) may be the stored relationship(s) between the belt webbing extension(s) and the belt path. Thus, at 128, the belt path module 90 may adjust the stored relationship(s) so that the belt path determined by the belt extension sensor(s) 33 (and 34, if present) corresponds to the belt path determined by the interior sensors 57.

[0098] At 130, the belt routing module 90 determines whether the stored (or current) belt routing is correct. The routing of the shoulder belt 18 is correct when the shoulder belt 18 is routed across the chest of an occupant in the seat 14 and over the occupant's shoulder. The routing of the lap belt 20 is correct for an occupant in the seat 14 without a child restraint seat when the lap belt 20 is routed over the occupant's lap or waist. The routing of the lap belt 20 is correct for a child restraint seat when the lap belt 20 is routed through the routing guides on the child restraint seat. If the stored belt routing is correct, the method continues at 132. Otherwise, the method continues at 134. At 134, the UID control module 92 controls the user interface device 54 to indicate that the seat belt 16 is not properly routed.

[0099] At 132, the sensor condition module 88 determines whether, after the initial determination and storage of the belt path, a change in shoulder belt webbing extension and / or lap belt webbing extension, as measured by the belt extension sensor(s) 33 (and 34, if present), is greater than a second delta value. The second delta value may be a second predetermined difference between the current webbing extension and the stored length of the safety belt 16 at its minimum extension length when the safety belt 16 is first worn by an occupant or when the safety belt 16 is first wrapped around a child restraint seat. The second delta value may be less than, greater than, or equal to the first delta value. If the change in shoulder belt extension and / or lap belt extension is greater than the second delta value, the method returns to 118. Otherwise, the method continues at 136.

[0100] At 136, the sensor condition module 88 determines whether the belt path changes after initially determining and storing the belt path. In making this determination, the sensor condition module 88 may use the same one of (i) the belt extension sensor(s) 33 (and 34, if present) and (ii) the interior sensors 57 that was used to determine the stored belt path. For example, if the belt extension sensor(s) 33 (and 34, if present) were used to determine the stored belt path, the sensor condition module 88 may determine at 136 whether the belt path determined using the belt extension sensor(s) 33 (and 34, if present) has changed. Conversely, if the interior sensors 57 were used to determine the stored belt path, the sensor condition module 88 may determine at 136 whether the belt path determined using the interior sensors 57 has changed. If the belt path has changed, the method returns to 118.Otherwise, the procedure continues at 138.

[0101] At 138, the sensor condition module 88 determines whether the buckle state of the seat belt 16 has changed from unbuckled to closed or from closed to unbuckled. In other words, the sensor condition module 88 determines whether an occupant has unbuckled or fastened the seat belt 16 during a trip. If the buckle state of the seat belt 16 has changed from unbuckled to closed or from closed to unbuckled, the method returns to 118. Otherwise, the method continues at 140. At 140, the sensor condition module 88 switches the interior sensors 57 to the idle state because the state of the seat belt 16 appears to be unchanged, and the method returns to 106.

[0102] Within the scope of the present invention, various modifications to the method of Fig. 3. For example, one or more (e.g. all) of 110, 112, 114, 132, 136 and 138 may be omitted, and the interior sensors 57 may be switched off during the entire process of Fig. 3 may be activated. In one example, the method may proceed from 108 directly to 116, in another example, the method may proceed from 130 and 134 directly to 106.

[0103] In another example, the order of 118 and 122 can be reversed. More specifically, after 116, the method can continue at 122. If 122 is true, the method can continue at 124. If 122 is false, the method can continue at 118. If 118 is true, the method can continue at 120. If 118 is false, the method can continue at 126. The rest of the method from Fig. 3 can proceed as described above.

[0104] In Fig. 4 is another variation of the procedure from Fig. 3. In this variation, 106 and 110 have been omitted and 114 and 140 have been replaced by 142 and 144 respectively. Otherwise, the procedure of Fig. 4 identical to the procedure of Fig. 3.

[0105] At 142, the sensor state module wakes up both the belt retraction sensor(s) 33 (and 34, if present) and the interior sensors 57. At 144, the sensor state module 88 switches both the belt retraction sensor(s) 33 (and 34, if present) and the interior sensors 57 to the sleep state. Thus, in the method of Fig. 4 activates both the tape extraction sensor(s) 33 (and 34, if present) and the interior sensors 57 and puts them into the idle state. This is the main difference between the procedure of Fig. 4 and the procedure of Fig. 3, since the procedure of Fig. 3 the sensor state module 88 only wakes up the interior sensors 57 and puts them into sleep mode.

[0106] In Fig. 5A illustrates a method for selecting (i) the belt retraction sensor(s) 33 (and 34, if present) or (ii) the interior sensors 57 as the primary sensors. The method of Fig. 5A can be used at 126 of Fig. 3 or Fig. 4. At 152, the belt routing module 90 determines whether the interior sensors 57 detect the shoulder belt webbing 18. If the interior sensors 57 detect the shoulder belt 18, the method continues at 154. Otherwise, the method continues at 156. At 156, the belt routing module 90 selects the belt extension sensor(s) 33 (and 34, if present) as the primary sensors for determining belt routing.

[0107] At 154, the belt path module 90 determines whether the belt path confidence determined with the shoulder belt extension sensor 33 and / or the lap belt extension sensor 34 is greater than a first percentage. The first percentage may be predetermined. If the belt path confidence determined with the belt extension sensor(s) 33 and / or 34 is greater than the first percentage, the method continues at 156. Otherwise, the method continues at 158.

[0108] When determining the belt path based on the input from the belt extension sensor(s) 33 (and 34, if present), the belt path module 90 may assign a confidence (e.g., a percentage) to each of the possible belt paths based on various factors. For example, the belt path module 90 may assign a high confidence to all possible lap belt paths when determining the lap belt path using the belt extension sensor(s) 33 (and 34, if present) in any condition. In another example, when determining the shoulder belt paths using the belt extension sensor(s) 33 (and 34, if present), the belt path module 90 may assign a low confidence to all possible shoulder belt paths if the belt path determined using the interior sensors 57 is incorrect.The belt path module 90 may select the one(s) of the possible seat belt paths that has(have) the highest confidence and compare that confidence to the first percentage at 154.

[0109] At 158, the belt path module 90 determines whether the belt path confidence determined using the interior sensors 57 is greater than a second percentage. The second percentage may be the same as the first percentage and / or may be predetermined. If the belt path confidence determined using the interior sensors 57 is greater than the second percentage, the method continues at 160. Otherwise, the method continues at 156. At 160, the belt path module 90 selects the interior sensors 57 as the primary sensors for determining the belt path.

[0110] When determining the belt path based on the inputs from the interior sensors 57, the belt path module 90 may assign a confidence (e.g., a percentage) to each of the possible belt paths based on various factors. For example, when determining the belt path using the interior sensors 57, the belt path module 90 may assign low confidence to all possible belt paths when the field of view of the interior sensors 57 is partially or completely obscured. In another example, when determining the shoulder belt path using the interior sensors 57, the belt path module 90 may assign high confidence to all possible incorrect shoulder belt paths. Possible incorrect shoulder belt paths include across the chest from the shoulder, across the chest and under the arm, on the wrong side of the head and across the chest to the buckle, and behind the back.The belt routing module 90 may select the one(s) of the possible seat belt routings (determined using the interior sensors 57) that has / have the highest confidence and compare that confidence to the second percentage at 158.

[0111] In Fig. 5B illustrates another method for selecting (i) the belt retraction sensor(s) 33 (and 34, if present) and (ii) the interior sensors 57 as primary sensors. The method of Fig. 5B can be found at 126 of Fig. 3 or Fig. 4. The procedure of Fig. 5B is similar or identical to the procedure of Fig. 5A, except that 154 and 158 of Fig. 5A were replaced by 153 and 155 respectively. In addition, the belt routing module 90 in the method of Fig. 5A assigns confidence values to the belt paths determined with the belt retraction sensor(s) 33 (and 34, if present) and the interior sensors 57, but this step is in Fig. 5A. In contrast, this step is not shown in Fig. 5B at 153.

[0112] At 152, the belt routing module 90 determines whether the interior sensors 57 detect the shoulder belt webbing 18. If the interior sensors 57 detect the shoulder belt webbing 18, the method continues at 153. Otherwise, the method continues at 156. At 156, the belt routing module 90 selects the belt extension sensor(s) 33 (and 34, if present) as the primary sensors for determining belt routing.

[0113] At 153, the belt path module 90 assigns a first confidence to the seat belt path determined with the belt retraction sensor(s) 33 (and 34, if present) and assigns a second confidence to the seat belt path determined with the interior sensors 57. The belt path module 90 may identify a plurality of possible seat belt paths based on the input from the belt retraction sensor(s) 33 (and 34, if present) and assign a confidence to each of these possible seat belt paths based on various factors, as discussed above. The method may then set the first confidence equal to the highest of the confidences for the possible seat belt paths identified based on the input from the belt retraction sensor(s) 33 (and 34, if present).Similarly, the belt routing module 90 may identify a plurality of possible seatbelt routings based on the input from the interior sensors 57 and assign a confidence to each of these possible seatbelt routings based on various factors, as described above. The method may then set the second confidence equal to the highest of the confidences for the possible seatbelt routings identified based on the input from the interior sensors 57.

[0114] At 155, the belt routing module 90 determines whether the first confidence is greater than the second confidence. If the first confidence is greater than the second confidence, the method continues at 156. Otherwise, the method continues at 160. At 160, the belt routing module 90 selects the interior sensors 57 as the primary sensors for determining the belt routing.

[0115] In Fig. 6 shows a method for taking into account the posture of an occupant in the seat 14 when monitoring the belt path 16. The method of Fig. 6 may be used in conjunction with one of the procedures of Fig. 3 and Fig. 4. If the procedure of Fig. 6 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 6, which corresponds to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0116] At 162, the sensor condition module 88 awakens the interior sensors 57 if the interior sensors 57 are not already awake. 162 may be performed when a change in shoulder and / or lap belt webbing extension is greater than a third delta value relative to (i) the extension when the interior sensors 57 were at rest or (ii) a stored length of the seat belt 16 at its minimum extension when first worn by an occupant or when first routed around a child restraint seat. At 164, the belt routing module 90 monitors the belt routing using the interior sensors 57. At 166, the occupant posture module 86 monitors the posture of an occupant in the seat 14 based on inputs from the interior sensors 57.

[0117] At 168, the occupant posture module 86 determines whether the occupant posture is not upright. If the occupant posture is not upright, the method continues at 170. Otherwise, the method ends or continues to a step in the method of Fig. 3 or Fig. 4 (e.g. 108 or 132).

[0118] At 170, the belt routing module 90 determines whether the belt routing determined using the interior sensors 57 confirms the occupant posture and the belt webbing extensions measured by the belt routing sensor(s) 33 (and 34, if present). For example, the belt routing module 90 may determine whether the belt routing determined using the interior sensors 57 matches a belt routing determined using the belt extension sensor(s) 33 (and 34, if present) when the occupant's non-upright posture is taken into account. In other words, the belt routing module 90 may confirm that a non-upright occupant posture is the reason why the belt routing determined using the belt extension sensor(s) 33 (and 34, if present) is different than the belt routing using the interior sensors 57.

[0119] If the belt path determined with the interior sensors 57 confirms the occupant posture and belt webbing extensions, the method continues at 172. Otherwise, the method continues at 174. At 174, the belt path module 90 selects the interior sensors 57 as the primary sensors. Thus, if the belt path determined with the belt extension sensor(s) 33 (and 34, if present) does not match the belt path determined with the interior sensors 57 and the occupant's non-upright posture is not the reason for the discrepancy, the belt path module 90 selects the interior sensors 57 as the primary sensors. At 172, the UID control module 92 controls the user interface device 54 to instruct the occupant to sit upright.

[0120] In Fig. 7 shows a method for taking rapid braking into account when monitoring the belt path 16. The method of Fig. 7 may be used in conjunction with one of the procedures of Fig. 3 and Fig. 4. If the procedure of Fig. 7 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 7, which corresponds to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0121] At 176, the vehicle accelerometer 49 monitors (e.g., repeatedly measures) the acceleration of the vehicle. At 178, the belt path module 90 determines whether a rapid braking event has occurred. The belt path module 90 may determine that a rapid braking event has occurred if the vehicle decelerates at a speed greater than a predetermined speed, optionally for a predetermined period of time. If a rapid braking event has occurred, the method continues at 180. Otherwise, the method ends or continues to a step in the method of Fig. 3 or Fig. 4 (e.g. 116 or 132).

[0122] At 180, the sensor status module 88 wakes up the interior sensors 57. At 182, the belt routing module 90 monitors the belt routing using the interior sensors 57. At 184, the belt routing module 90 stores the belt routing determined using the interior sensors 57. At 186, the occupant posture module 86 monitors the posture of an occupant in the seat 14 using the interior sensors 57.

[0123] At 188, the occupant posture module 86 determines whether the occupant's posture is upright. If the occupant's posture is upright, the method continues at 200. Otherwise, the method continues at 201. At 200, the belt path module 90 adjusts the stored relationship between the belt webbing extensions measured by the belt path sensor(s) 33 (and 34, if present) and the belt path. At 201, the UID control module 92 controls the user interface device 54 to instruct the occupant to sit upright, and then the occupant posture module 86 continues to determine whether the posture is upright.

[0124] During a sudden stop, the torso of an occupant in seat 14 pushes into the shoulder belt 18 and lap belt 20 due to the occupant's momentum, causing the shoulder and lap belts 18 and 20 to quickly extend from the first retractor 22 and the second retractor 24 (if present). The spool(s) in the first retractor 22 and the second retractor 24 (if present) in turn lock to prevent further extension of the shoulder and lap belts 18 and 20 from the first retractor 22 and the second retractor 24 (if present). This causes the shoulder and lap belts 18 and 20 to wrap more tightly around the spool(s), thereby reducing the shoulder and lap belt extensions relative to the rotational position of the spool(s). The belt routing module 90 therefore adjusts the stored relationship between webbing extension and belt routing to account for this change.

[0125] The belt routing module 90 may also store a relationship between (i) the rotational position of spools within the first and second retractors 22 and 24 and (ii) the extension of the shoulder and lap belts 18 and 20, respectively. The length or extension of the shoulder and lap belts 18 and 20 stored at 200 may be referred to as a stored static length. The stored static lengths may be the minimum belt webbing extension when the seat belt 16 is worn by the occupant in its currently routed configuration (e.g., across the chest and over the shoulder, across the chest and away from the shoulder, across the chest and under the arm, behind the back). The new statically stored lengths may replace the old stored static lengths determined within a time window after the seat belt 16 was fastened for the original seat belt configuration.After 200 the process ends or continues to a step in the process of . Fig. 3 or Fig. 4 (e.g. 116 or 132).

[0126] In Fig. 8 shows a method which, when monitoring the belt path of the safety belt 16, takes into account the refastening of the safety belt 16 by an occupant. The method of Fig. 8 may be used in conjunction with one of the methods of Fig. 3 and Fig. 4. If the procedure of Fig. 8 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 8, which corresponds to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0127] At 202, the shoulder belt extension sensor 33 and the lap belt extension sensor 34 (if present) monitor (i.e., repeatedly measure) the extension of the shoulder and lap belts 18 and 20, respectively. At 204, the buckle sensor 32 monitors the buckle state of the safety belt 16. In other words, the buckle sensor 32 repeatedly determines whether the safety belt 16 is fastened or unfastened.

[0128] At 208, the sensor condition module 88 determines whether the buckle state of the safety belt 16 has changed from unfastened to fastened. If the buckle state of the safety belt 16 has changed from unfastened to fastened, the method continues at 210. Otherwise, the method returns to 202.

[0129] At 210, the sensor condition module 88 wakes up the interior sensors 57. At 212, the belt routing module 90 monitors the belt routing using the interior sensors 57. At 214, the belt routing module 90 determines whether the safety belt 16 is routed across the chest of an occupant in the seat 14 and over a shoulder of the occupant. The belt routing module 90 makes this decision based on the belt routing determined using the interior sensors 57. If the safety belt 16 is routed across the chest and over the shoulder, the method continues at 216. Otherwise, the method continues at 218. At 218, the UID control module 92 controls the user interface device 54 to indicate that the safety belt 16 is not properly routed. After 218, the method may return to 214 (dashed arrow in Fig. 8) or end and / or with another step in Fig. 3 or Fig. 4 continue.

[0130] At 216, the belt routing module 90 adjusts the stored relationship between the webbing extensions and the belt routing. Thus, each time an occupant in seat 14 unfastens and refastens the seat belt 16 while driving, the belt routing module 90 adjusts the stored relationship between the webbing extensions and the belt routing based on the inputs from the interior sensors 57. This improves the accuracy of the belt routing determined by the belt extension sensor(s) 33 (and 34, if present), which is particularly beneficial when the interior sensors 57 are placed in the idle state.

[0131] In addition to or instead of adjusting the stored relationship between the belt webbing extensions and the belt path at 216, the belt path module 90 may reset the stored static lengths of the shoulder and lap belts 18 and 20. After 216, the method ends and / or continues with another step in Fig. 3 or Fig. 4 continued.

[0132] In Fig. 9 illustrates a method for adjusting a stored relationship between spool positions and belt webbing extensions when the seat belt 16 is stowed. The method of Fig. 9 may be used in conjunction with one of the procedures of Fig. 3 and Fig. 4. If the procedure of Fig. 9 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 9, which corresponds to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0133] At 220, the sensor condition module 88 awakens the interior sensors 57 if the interior sensors 57 are not already awake. 220 may be executed when a change in shoulder and / or lap belt extension is greater than a fourth delta value relative to (i) the extension when the interior sensors 57 were at rest or (ii) a stored length of the safety belt 16 at its minimum extension when first worn by an occupant or when first routed around a child restraint seat. At 222, the belt routing module 90 monitors the belt routing using the interior sensors 57. At 224, the belt routing module 90 determines whether the belt routing determined using the interior sensors 57 indicates that the safety belt 16 is properly stowed.For example, the belt routing module 90 may determine that the safety belt 16 is properly stowed when the shoulder belt webbing 18 and the lap belt webbing 20 extend in an approximately straight line along or adjacent to the seatback 62. If the safety belt 16 is properly stowed, the method continues at 226.

[0134] Otherwise, the procedure will be terminated and / or continued with another step in the procedure of Fig. 3 or Fig. 4 continued.

[0135] At 226, the belt routing module 90 adjusts the stored relationship between the positions of the spools within the first retractor 22 and the second retractor 24 (if present) and the extensions of the shoulder and lap belts 18 and 20, respectively. In one example, if the interior sensors 57 indicate that the seat belt is properly stowed, the belt routing module 90 stores the current spool position and corresponding webbing extensions as the stowed webbing extension. The belt routing module 90 then adjusts the relationships between all other possible spool positions and webbing extensions for other routing conditions accordingly, since the stowed webbing extension is used as the measured starting point for the extensions in the other routing conditions.Then, as the seat belt 16 is extended, the belt routing module 90 can accurately determine the shoulder and lap belt extensions based on the rotational positions of the spools within the first retractor 22 and the second retractor 24 (if present). The belt routing module 90 can then determine the belt routing based on the accurate belt webbing extension using this stowed belt webbing extension calibration technique.

[0136] At 228, the belt routing module 90 determines whether the shoulder belt extension and / or the lap belt extension is greater than a first amount. The first amount may be predetermined and / or may be the maximum allowable belt webbing extension when the safety belt 16 is properly stowed. If the shoulder belt extension and / or the lap belt extension is greater than the first amount, the method continues at 230. Otherwise, the method terminates and / or continues with another step in the method of Fig. 3 or Fig. 4. At 230, the UID control module 92 controls the user interface device 54 to send a message to the occupant indicating that the seat belt 16 or sensor system needs servicing because the output extension is shorter than physically possible.

[0137] In Fig. 10 shows a method for adjusting a stored relationship between belt webbing extension and belt path when a child seat is present on the vehicle seat 14. The method of Fig. 10 may be used in conjunction with one of the methods of Fig. 3 and Fig. 4. If the procedure of Fig. 10 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 10, which corresponds to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0138] At 232, the sensor condition module 88 awakens the interior sensors 57 if the interior sensors 57 are not already awake. 232 may be executed when a change in shoulder and / or lap belt extension is greater than a fourth delta value relative to (i) the extension when the interior sensors 57 were at rest or (ii) a stored length of the safety belt 16 at its minimum extension length when first worn by an occupant or when first looped around a child restraint seat. At 234, the belt routing module 90 monitors the belt routing using the interior sensors 57. At 236, the occupant detection module 84 monitors the occupancy of the seat 14 using the interior sensors 57. At 238, the occupant detection module 84 determines whether an object, such as a child restraint seat, is present on the vehicle seat 14 or whether an occupant without a child restraint seat is present on the vehicle seat 14.If an object such as a child restraint seat is present in the vehicle seat 14, the method continues at 240. Otherwise, the method continues at 242.

[0139] At 240, the belt routing module 90 adjusts the stored relationship between webbing extension and belt routing to settings specific for use with a child restraint seat. Additionally or alternatively, the belt routing module 90 may adjust the stored relationship between the spool position and webbing extension. For example, the belt routing module 90 may reset the stored static length(s) of the safety belt 16.

[0140] At 242, the belt routing module 90 adjusts the stored relationship between belt webbing extension and belt routing to settings specific to an occupant in the vehicle seat 14 without a child safety seat. Additionally or alternatively, the belt routing module 90 may adjust the stored relationship between the spool position and belt webbing extension. For example, the belt routing module 90 may reset the stored static length(s) of the safety belt 16. After 240 or 242, the method ends and / or proceeds to another step in the method of Fig. 3 or Fig. 4. If the occupant detection module 84 determines at 238 that the vehicle seat 14 is empty, the occupant detection module 84 may proceed to either 240 or 242. In other words, an empty seat may be included in either the object / child restraint seat category or the occupant directly on the seat category.

[0141] In Fig. 11 shows a method for taking changes in seat position into account when monitoring the belt path. The method of Fig. 11 may be used in conjunction with any of the procedures of Fig. 3 and Fig. 4. If the procedure of Fig. 11 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 11, which corresponds to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0142] At 244, the seat position module 82 monitors (e.g., repeatedly measures) the position of the seat 14. The seat position module 82 may monitor the seat position based on the inputs from the seat position sensors 59, 60. Additionally or alternatively, the seat position module 82 may monitor the seat position based on the inputs from the interior sensors 57.

[0143] At 246, the belt routing module 90 determines whether the seat 14 is moving or has just moved. If the seat 14 is moving or has just moved, the method continues at 248. Otherwise, the method terminates and / or continues with another step in Fig. 3 or Fig. 4. At 248, the sensor status module 88 awakens the interior sensors 57 if the interior sensors 57 are not already awake. At 250, the belt routing module 90 monitors the belt routing using the interior sensors 57.

[0144] At 252, the belt routing module 90 determines whether the safety belt 16 is routed across the chest and over the shoulder of an occupant in the seat 14. If the safety belt 16 is routed across the chest and over the shoulder of the occupant, the method continues at 254. Otherwise, the method continues at 256. At 254, the belt routing module 90 adjusts the stored relationship between webbing extension and belt routing to account for the change in seat position. 254 may be executed after the seat 14 stops moving by either waiting until the seat 14 stops moving to execute 254 or by performing the method of Fig. 11 is repeated. At 256, the UID control module 92 controls the user interface device 54 to send a message to the occupant indicating that the seat belt 16 is not properly fastened. After 256, the method may return to 252 (dashed arrow in Fig. 11), or the procedure may end and / or continue with another step in Fig. 3 or Fig. 4 continue.

[0145] In Fig. 12 shows a method for taking into account changes in the position of the guide loop when monitoring the belt path. The method of Fig. 12 may be used in conjunction with any of the procedures of Fig. 3 and Fig. 4. If the procedure of Fig. 12 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 12, which correspond to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0146] At 258, the belt routing module 90 monitors (e.g., repeatedly measures) the position of the guide loop 31. The belt routing module 90 may monitor the position of the guide loop based on the input from the guide loop position sensor 61. Additionally or alternatively, the belt routing module may monitor the position of the guide loop based on the inputs from the interior sensors 57.

[0147] At 260, the belt routing module 90 determines whether the guide loop 31 is moving or has just moved. If the guide loop 31 is moving or has just moved, the method continues at 262. Otherwise, the method is terminated and / or continues with another step in the method of Fig. 3 or Fig. 4. At 262, the sensor status module 88 awakens the interior sensors 57 if the interior sensors 57 are not already awake. At 264, the belt routing module 90 monitors the belt routing using the interior sensors 57.

[0148] At 266, the belt routing module 90 determines whether the safety belt 16 is routed across the chest and over the shoulder of an occupant in the seat 14. If the safety belt 16 is routed across the chest and over the shoulder of the occupant, the method continues at 268. Otherwise, the method continues at 270. At 268, the belt routing module 90 adjusts the stored relationship between the webbing extension and the belt routing to account for the change in the position of the guide loop. 268 may be executed after the guide loop 31 stops moving by either waiting until the guide loop 31 stops moving to execute 268 or by performing the method of Fig. 11 is repeated. At 270, the UID control module 92 controls the user interface device 54 to send a message to the occupant indicating that the seat belt 16 is not properly fastened. After 270, the method may return to 266 (dashed arrow in Fig. 11), or the procedure may end and / or continue with another step in Fig. 3 or Fig. 4 continue.

[0149] Fig. 13 shows a method for determining whether the path guide 17 is being used and for communicating with an occupant about whether the path guide 17 should be used. The method of Fig. 13 may be used in conjunction with any of the procedures of Fig. 3 and Fig. 4. If the procedure of Fig. 13 in connection with one of the procedures of Fig. 3 and Fig. 4, all steps of the procedure of Fig. 13, which correspond to the steps in the procedures of Fig. 3 and Fig. 4 are redundant, are omitted.

[0150] At 278, the occupant sensing module 84 monitors the occupancy of the seat 14 using the interior sensors 57. At 280, the belt routing module 90 monitors the belt routing using the interior sensors 57. The belt routing module 90 may also identify the position of the routing guide 17 and / or the position of the safety belt 16 relative to the routing guide 17. At 282, the belt routing module 90 determines whether the safety belt 16 passes through the routing guide 17. If the safety belt 16 passes through the routing guide 17, the method continues at 284. Otherwise, the method continues at 286.

[0151] At 284, the occupant detection module 84 determines whether a large occupant (e.g., an adult) is sitting on the seat 14 without a child safety seat. The occupant detection module 84 may make this determination based on the detected occupant size, the path geometry, and / or the extension length. If a large occupant is sitting on the seat 14 without a child safety seat, the method continues at 288. Otherwise, the method terminates and / or continues with another step in Fig. 3 or Fig. 4. At 288, the UID control module 92 controls the user interface device 54 to send a message to the occupant indicating that the seat belt 16 should not be routed through the routing guide 17. If the seat belt 16 has just been routed through the routing guide 17, the belt routing module 90 may adjust the stored static length.

[0152] At 286, the occupant detection module 84 determines whether a small occupant (e.g., a child) is sitting on the seat 14 without a child safety seat. The occupant detection module 84 may make this determination based on the detected occupant size, the path geometry, and / or the extension length. If a small occupant is sitting on the seat 14 without a child safety seat, the method continues at 290. Otherwise, the method terminates and / or continues with another step in Fig. 3 or Fig. 4. At 290, the UID control module 92 controls the user interface device 54 to send a message to the occupant indicating that the seat belt 16 should be routed through the routing guide 17. If the seat belt 16 has just been removed from the routing guide 17, the belt routing module 90 may adjust the stored static length. After 288 and 290, the method ends and / or proceeds to another step in Fig. 3 or Fig.4 over.

[0153] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, e.g., “connected,” “engaging,” “coupled,” “adjacent,” “beside,” “on,” “over,” “under,” and “disposed.” When a relationship between a first and a second element is not expressly described as “direct” in the above invention, that relationship may be a direct relationship in which no other intervening elements are present between the first and second elements, but it may also be an indirect relationship in which one or more intervening elements (either spatial or functional) are present between the first and second elements.

[0154] As used herein, the phrase "at least one of A, B, and C" should be construed as logical (A OR B OR C) using a non-exclusive logical OR, and not as "at least one of A, at least one of B, and at least one of C."

[0155] In the figures, the direction of an arrow, as indicated by the arrowhead, generally indicates the flow of information (e.g., data or instructions) of interest for the representation. For example, if element A and element B exchange a lot of information, but the information passed from element A to element B is relevant for the representation, the arrow may point from element A to element B. This unidirectional arrow does not imply that no further information is passed from element B to element A. In addition, for information sent from element A to element B, element B may send requests for or acknowledgments of receipt of the information to element A.

[0156] In this application, including the definitions below, the term "module" or the term "controller" may be replaced by the term "circuit." The term "module" may refer to, be a part of, or contain: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); a processor circuit (common, dedicated, or group) that executes code; a memory circuit (common, dedicated, or group) that stores the code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, e.g., in a system-on-chip.

[0157] The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any module of the present invention may be distributed among multiple modules connected via interface circuits. For example, multiple modules may enable load balancing. In another example, a server module (also referred to as a remote or cloud module) may perform some functions on behalf of a client module.

[0158] The term code, as used above, may include software, firmware, and / or microcode and may refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuit" includes a single processor circuit that executes some or all of the code from multiple modules. The term group processor circuit includes a processor circuit that, in combination with other processor circuits, executes some or all of the code from one or more modules. References to multiple processor circuits include multiple processor circuits on discrete chips, multiple processor circuits on a single chip, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or any combination of the above.The term "shared memory circuit" refers to a single memory circuit that stores some or all of the code from multiple modules. The term "group memory circuit" refers to a memory circuit that, in combination with other memories, stores some or all of the code from one or more modules.

[0159] The term "memory circuit" is a subset of the term "computer-readable medium." The term "computer-readable medium," as used herein, does not include transitory electrical or electromagnetic signals propagating through a medium (e.g., on a carrier wave); the term "computer-readable medium" can therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible, computer-readable medium include non-volatile memory circuits (e.g., a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (e.g., a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (e.g., an analog or digital magnetic tape or a hard disk drive), and optical storage media (e.g.,a CD, a DVD or a Blu-ray Disc).

[0160] The devices and methods described in this application may be implemented in part or in whole by a special-purpose computer formed by configuring a general-purpose computer to perform one or more specific functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a skilled technician or programmer.

[0161] The computer programs contain processor-executable instructions stored on at least one non-transitory, tangible, computer-readable medium. The computer programs may also contain or access stored data. The computer programs may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0162] The computer programs may contain: (i) descriptive text to be parsed, e.g. HTML (Hypertext Markup Language), XML (Extensible Markup Language) or JSON (JavaScript Object Notation) (ii) assembly code, (iii) object code generated from the source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of examples only: The source code may be written using the syntax of languages such as C, C++, C#, ObjectiveC, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK and Python®.

Claims

[1] System (10) comprising: a seat belt routing module (90) configured to: Determining the path of a safety belt (16) relative to an occupant on a seat (14) of a vehicle based on an input from a webbing extension sensor (33, 34) that measures webbing extension of the safety belt (16); and Determining the seat belt path based on an input from an interior sensor (57) located in an interior of the vehicle, the interior sensor (57) comprising at least one of: a camera, an infrared sensor, an ultrasonic sensor, a radar sensor, and a lidar sensor; and a user interface device (UID) control module (92) configured to control a user interface device (54) to indicate that the seat belt (16) is not properly fastened when: the seat belt path determined using the belt extension sensor (33, 34) and / or the interior sensor (57) is incorrect; and the seat belt path determined by the belt webbing extension sensor (33, 34) corresponds to the seat belt path determined by the interior sensor (57); characterized by , that the system (10) further comprises a sensor condition module (88) configured to activate the interior sensor (57) when a first change in belt webbing extension is greater than a first delta value and when a buckle sensor (32) indicates that the seat belt (16) is closed; and wherein the sensor condition module (88) is further configured to deactivate the interior sensor (57) if, after the seat belt path module (90) has determined the seat belt path using the interior sensor (57), a second change in belt webbing extension is less than a second delta value and the buckle sensor (32) still indicates that the seat belt (16) is closed. [2] System (10) according to claim 1, wherein: if the seat belt path determined by the belt webbing extension sensor (33, 34) does not correspond to the seat belt path determined by the interior sensor (57), the seat belt path module (90) is configured to select either the belt webbing extension sensor (33, 34) or the interior sensor (57) as the primary sensor; and the UID control module (92) is configured to control the user interface device (54) to indicate that the seat belt (16) is not properly fastened if the seat belt path determined by the primary sensor is incorrect. [3] The system (10) of claim 2, further comprising an occupant posture module (86) configured to determine a posture of the occupant based on the input from the interior sensor (57), wherein the seatbelt routing module (90) is configured to select the webbing retraction sensor (33, 34) or the interior sensor (57) as the primary sensor based on at least one of: whether the occupant’s posture is not upright; whether the interior sensor (57) detects a shoulder strap of the safety belt (16); a confidence in the seat belt path determined using the belt webbing extension sensor (33, 34); and a confidence in the seat belt path determined using the interior sensor (57). [4] The system (10) of claim 1, wherein the seat belt routing module (90) is configured to: Storing a relationship between the belt webbing extension and the seat belt path; and Determine the seat belt path based on the belt webbing extension using the stored relationship between the belt webbing extension and the seat belt path. [5] The system (10) of claim 4, wherein the seat belt routing module (90) is configured to adjust the stored relationship when a buckle sensor (32) indicates that the seat belt (16) is closed and an acceleration sensor indicates that a deceleration of the vehicle is greater than a predetermined rate. [6] The system (10) of claim 4, further comprising an occupant detection module configured to detect whether a child restraint seat is present on the vehicle seat (14), wherein the seat belt routing module (90) is configured to adjust the stored relationship based on whether the child restraint seat is present on the vehicle seat (14). [7] The system (10) of claim 4, wherein the seatbelt routing module (90) is configured to adjust the stored relationship when: the interior sensor (57) and / or a seat position sensor (60) indicates that the vehicle seat (14) has moved; and based on the input from the interior sensor (57), the seat belt routing module (90) determines that the seat belt (16) is properly fastened. [8] The system (10) of claim 4, wherein the seatbelt routing module (90) is configured to adjust the stored relationship when: the interior sensor (57) and / or a guide loop position sensor (61) indicates that a guide loop (31) for the safety belt (16) has moved; and based on the input from the interior sensor (57), the seat belt routing module (90) determines that the seat belt (16) is properly fastened.

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