Anti-pinch detection system using power dissipation monitoring

Abstract

A method for detecting a clamping condition of a seat assembly for use in a motor vehicle comprises determining a rotational speed of an output shaft of an electric motor, determining a new time constant TCnew for the rotational speed, and detecting the clamping condition if the new time constant TCnew is greater than a calibrated calibration factor G multiplied by a predetermined time constant TCn. A second method for detecting a clamping condition comprises determining a power difference between an electrical power provided to the motor and a mechanical power delivered by the motor, and calculating an amount of energy E by integrating the power difference over a period of time. A second method determines that a gripping condition has occurred based on the amount of energy E and based on an energy threshold TH.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application 63 / 532,459, filed August 14, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This invention relates to a seat assembly for motor vehicles. More specifically, this invention relates to an anti-pinch detection system utilizing power dissipation monitoring for use in automotive seat assemblies. Background Technology

[0004] Motor vehicles typically include one or more seat assemblies having seat cushions and seat backs for supporting passengers above the vehicle floor. It is known that some seat assemblies can be repositioned along opposing seat tracks. Furthermore, it is known that seat assemblies include input switches, controllers, and motors. Typically, the input switches are electrically connected to the controller and configured to input a request to the controller. Additionally, the controller is electrically connected to the motor and configured to selectively supply power to the motor. The motor is typically operatively coupled to a component of the seat assembly and configured to reposition that component when the controller supplies power to the motor.

[0005] However, the seat assembly may encounter obstacles when the motor receives power. A clamping condition occurs when a portion of the seat assembly encounters an obstacle or impact while the motor is being powered. One type of clamping condition is a hard impact, where the seat assembly encounters a hard object as the controller supplies power to the motor. A hard impact can cause the motor to stall and draw a large amount of current. A second type of clamping condition is soft clamping, where the obstacle is compressible. Due to soft clamping, the current drawn by the motor may increase slowly over time.

[0006] Typically, if the current drawn by the motor exceeds the maximum hardware current limit, the controller will terminate power supply to the motor. The controller is usually configured to stop the motor upon detecting a power surge or other error. In some known seat assemblies, the controller includes current or position sensors for sensing inconsistencies in the movement of components or the motor. It is well known that the controller detects clamping conditions based on monitoring of the current and / or position sensors.

[0007] However, known methods may not detect obstacles before the motor stalls or draws a large amount of current. Furthermore, the controller may not detect soft-clamping conditions in time because changes in the amount of current drawn by the motor may increase at a slower rate than in the case of a hard impact. Additionally, known methods may fail to detect clamping conditions due to potential motor problems associated with aging and overuse scenarios.

[0008] It is desirable that the controller for the seat assembly perform anti-pinch detection, which can detect abnormal obstruction of movement and impeded motor movement. Furthermore, it is desirable that the controller detect hard impacts and soft pinching conditions before the motor draws maximum hardware current. Additionally, it is desirable to identify potential motor problems related to aging or overuse scenarios. Summary of the Invention

[0009] According to one embodiment, a method is provided for detecting the clamping condition of a seat assembly used in a motor vehicle. The seat assembly includes a controller operatively coupled to a motor having an output shaft and a Hall effect sensor configured to output a Hall effect pulse to the controller when the motor rotates the output shaft. The method includes the steps of: providing a calibration coefficient G, a predetermined time amount H1, and a predetermined time constant TC. n The method further includes the following steps: acquiring a first plurality of Hall effect pulses received from a Hall effect sensor during a first time period; and determining a first rotational speed of the output shaft during the first time period based on the first plurality of Hall effect pulses. new Determine the new time constant TC new Is it greater than the calibration coefficient G multiplied by the time constant TC? n At least time H1; and if the new time constant TC new Greater than the calibration factor G multiplied by the time constant TC n If at least time H1 is reached, it is determined that a pre-mature pinch has occurred.

[0010] According to a second embodiment, a method is provided for detecting the clamping condition of a seat assembly used in a motor vehicle, wherein the seat assembly includes a controller operatively coupled to a motor having an output shaft and a Hall effect sensor configured to output Hall effect pulses to the controller when the motor rotates the output shaft. The method includes the steps of: providing a predetermined energy threshold TH; acquiring a first voltage quantity and a first pulse width modulation (PWM) power quantity supplied to the motor during a first time period, a first current quantity drawn by the motor, and a first plurality of Hall effect pulses received from the Hall effect sensor; and determining a first electrical power supplied to the motor based on the first voltage quantity and the first current quantity during the first time period. The method further includes the steps of: determining a first mechanical power supplied by the motor based on the first PWM power quantity supplied to the motor during the first time period and the first plurality of Hall effect pulses received from the Hall effect sensor; determining a first power difference between the first electrical power and the first mechanical power during the first time period; determining a first energy quantity E1 by integrating the first power difference during the first time period; and determining that a preliminary clamping condition has occurred when the first energy quantity E1 is greater than the predetermined energy threshold TH.

[0011] According to a third embodiment, a method is provided for detecting the clamping condition of a seat assembly used in a motor vehicle, wherein the seat assembly includes a controller operatively coupled to a motor having an output shaft and a Hall effect sensor configured to output Hall effect pulses to the controller when the motor rotates the output shaft. The method includes the steps of: providing a predetermined energy threshold TH; acquiring a first voltage and a first pulse width modulation (PWM) power quantity supplied to the motor during a first time period, a first current quantity drawn by the motor, and a first plurality of Hall effect pulses received from the Hall effect sensor; and determining a first electrical power supplied to the motor based on the first voltage and the first current quantity during the first time period. The method further includes the steps of: determining a first mechanical power supplied by the motor based on the first PWM power quantity supplied to the motor during the first time period and the first plurality of Hall effect pulses received from the Hall effect sensor; determining a first power difference between the first electrical power and the first mechanical power during the first time period; and acquiring a second voltage and a second PWM power quantity supplied to the motor during a second time period, a second current quantity drawn by the motor, and a second plurality of Hall effect pulses received from the Hall effect sensor during a second time period. The method further includes the following steps: determining a second electrical power supplied to the motor based on a second voltage and a second current during a second time period; determining a second mechanical power supplied by the motor based on a second PWM power supplied to the motor during the second time period and a second plurality of Hall effect pulses received from a Hall effect sensor; determining a second power difference between the second electrical power and the second mechanical power during the second time period; and determining that a clamping condition has occurred when the second power difference is greater than a first power difference and greater than a predetermined energy threshold TH. Attached Figure Description

[0012] The advantages of the present invention will be readily apparent, as they will be more readily understood by referring to the following detailed description in conjunction with the accompanying drawings, in which:

[0013] Figure 1 This is a perspective view of a seat assembly according to an embodiment of the present invention, the seat assembly including a seat cushion, a seat back, a controller, components, and an electric motor having an output shaft;

[0014] Figure 2 When Figure 1 A graph showing the pulse width modulation (PWM) power supplied to the motor as the component moves between the first and second positions;

[0015] Figure 3 It is by Figure 1 The curve of the Hall effect pulses received by the controller over time;

[0016] Figure 4 When the electric motor moves the component between the first position and the second position Figure 1 A curve showing the rotational speed of the output shaft;

[0017] Figure 5 It is by Figure 1 A graph showing the Hall effect pulses received by the controller over time and the electrical power supplied to the motor by the controller;

[0018] Figure 6 It is when the component moves between the first position and the second position by Figure 1 A graph showing the current drawn by the electric motor;

[0019] Figure 7 It is supplied when the component moves between the first position and the second position. Figure 1 A graph showing the voltage curve of the electric motor;

[0020] Figure 8 This is a schematic diagram of a storage format for an ignition counter according to an embodiment of the present invention;

[0021] Figure 9 This is a control according to one embodiment of the present invention. Figure 1 Flowchart of the electric motor;

[0022] Figure 10 This is a flowchart of a sequence detection process according to an embodiment of the present invention;

[0023] Figure 11 This is a flowchart of an ignition counter according to an embodiment of the present invention;

[0024] Figure 12 This is a flowchart of an average current monitor according to one embodiment of the present invention;

[0025] Figure 13 According to one embodiment of the present invention, when the component moves between a first position and a second position, it is caused by... Figure 1 A graph showing the current drawn by the electric motor;

[0026] Figure 14 It is based on one embodiment of the present invention. Figure 1 A schematic diagram showing the current drawn by the electric motor in intervals 1 to 9;

[0027] Figure 15 According to one embodiment of the present invention, when the component moves between a first position and a second position, it is caused by... Figure 1 A graph showing the current drawn by the electric motor;

[0028] Figure 16 This is a flowchart of an overcurrent monitor according to an embodiment of the present invention;

[0029] Figure 17 This is a schematic diagram of a storage format for an average current monitor according to an embodiment of the present invention;

[0030] Figure 18 This is a schematic diagram of a storage format for an overcurrent monitor according to an embodiment of the present invention;

[0031] Figure 19 This is a schematic diagram of a storage format for storing location and PWM range according to an embodiment of the present invention;

[0032] Figure 20 yes Figure 7 An enlarged view of part 20 of the medium voltage curve;

[0033] Figure 21 yes Figure 6 An enlarged view of part 21 of the medium current curve;

[0034] Figure 22 It is a graph showing the change of electrical power and mechanical power over time according to one embodiment of the present invention;

[0035] Figure 23 It is a graph showing the change of mechanical force over time according to one embodiment of the present invention;

[0036] Figure 24 This is a graph showing the change of HE Delta_T over time according to an embodiment of the present invention;

[0037] Figure 25 This is a graph showing the electrical power and HE Delta_T versus time according to an embodiment of the present invention, and it also shows the change of EP. ave and DT ave The value is stored in memory;

[0038] Figure 26 This is a flowchart for P5 event analysis according to an embodiment of the present invention;

[0039] Figure 27 This illustrates how EP changes over time according to one embodiment of the present invention. ave and DT ave A diagram illustrating how the values ​​are stored in memory and how a health status assessment is completed;

[0040] Figure 28 This is the average electrical power (EP) for data in storage buffers M and M' according to one embodiment of the present invention.ave ) and the average HE Delta_T (DT) ave A graph comparing the curves;

[0041] Figure 29 This is a flowchart of a P6 clamping detection according to an embodiment of the present invention;

[0042] Figure 30 This is a flowchart of a region C clamping detection according to an embodiment of the present invention;

[0043] Figure 31 It is a graph showing the changes in electrical power and mechanical power over time according to an embodiment of the present invention, and also shows the soft clamping condition;

[0044] Figure 32 It is based on Figure 31 The graph shows the change of electrical power over time in the embodiment, and also shows the soft clamping condition;

[0045] Figure 33 It is based on Figure 31 The graph shows the rotational speed as a function of time in the implementation method, and also illustrates the soft clamping condition;

[0046] Figure 34 It is a graph showing the changes in electrical power and mechanical power over time according to an embodiment of the present invention, and illustrates a hard collision;

[0047] Figure 35 It is based on Figure 34 The implementation of the method is illustrated with a graph showing the change of electrical power over time and the hard impact.

[0048] Figure 36 It is based on Figure 34 The implementation of the method is shown in the graph of the rotational speed as a function of time, and a hard collision is also shown.

[0049] Figure 37 This is a graph showing the changes in electrical power and mechanical power over time according to another embodiment of the present invention, and a first scenario is shown;

[0050] Figure 38 This is a graph showing the changes in electrical power and mechanical power over time according to another embodiment of the present invention, and a second scenario is shown;

[0051] Figure 39 This is a graph showing the changes in electrical power and mechanical power over time according to another embodiment of the present invention, and a third scenario is shown;

[0052] Figure 40 This is a graph showing the changes in electrical power and mechanical power over time according to another embodiment of the present invention, and a fourth scenario is shown;

[0053] Figure 41 This is a graph showing the changes in electrical power and mechanical power over time according to another embodiment of the present invention, and a fifth scenario is shown;

[0054] Figure 42 A schematic diagram showing the value of the energy threshold TH according to an embodiment of the present invention is illustrated;

[0055] Figure 43 This is a first flowchart for P6 clamping detection according to a second embodiment of the present invention;

[0056] Figure 44 This is a second flowchart for P6 clamping detection according to the second embodiment;

[0057] Figure 45 This is a flowchart of a P6 clamping detection method according to a third embodiment of the present invention; and

[0058] Figure 46 This is a diagram illustrating the detection boundary according to another embodiment of the present invention. Detailed Implementation

[0059] Figures 1 to 46 A motor vehicle seat assembly 10 with an anti-pinch detection system 12 according to an embodiment described herein is shown. Directional references used or shown in the specification, drawings, or claims, such as top, bottom, upper, lower, upward, downward, longitudinal, lateral, left, right, etc., are relative terms used for ease of description and are not intended to limit the scope of the invention in any way. Referring to the drawings, the same reference numerals indicate the same or corresponding parts throughout several views.

[0060] Figure 1 A perspective view of a vehicle seat assembly 10 is shown, which has a seat back 14 pivotally connected to a seat cushion 16, the seat cushion being slidably coupled to an opposing seat track 18, as is known in the art. The seat assembly 10 also includes a controller 20, a motor 22, a gearbox 24, a forward switch 25A, a reverse switch 25B, and a component 26. The controller 20 is electrically connected to the forward switch 25A, the reverse switch 25B, and the motor 22.

[0061] The electric motor 22 includes an output shaft 28 operably coupled to the gearbox 24. The electric motor 22 is configured to respond to a pulse-width modulation (PWM) power 34 provided by the controller 20. Figure 2The output shaft 28 is selectively rotated in a first rotation direction 30 and in the opposite second rotation direction 32, as is known in the art. Additionally, the motor 22 includes a Hall effect sensor 36 configured to output a Hall effect pulse 38 in response to rotation of the output shaft 28. Figure 3 The Hall effect pulse is received by controller 20. In some embodiments, as is known in the art, the PWM power 34 is adjusted using pulse width modulation (PWM). The amount of PWM power 34 is adjusted by increasing and / or decreasing the percentage of the PWM duty cycle 52, as will be discussed further below.

[0062] like Figure 1 As shown, gearbox 24 is operatively coupled to component 26 of seat assembly 10. Gearbox 24 is configured to reposition component 26 toward a first position 42 in a first direction 40 and toward a second position 46 in the opposite second direction 44, in response to rotation of output shaft 28 by motor 22 in a first rotation direction 30 and a second rotation direction 32, respectively. Seat assembly 10 also includes a rear stop 48 and a front stop 50, as are known in the art, defining the first position 42 and the second position 46, respectively. It should be understood that output shaft 28 of motor 22 may be operatively coupled to alternative components of seat assembly 10, wherein rotation of output shaft 28 causes one component to be displaced and / or pivoted relative to a second component (as are known in the art), without altering the scope of the invention.

[0063] During operation, when component 26 is in the first position 42 and controller 20 receives a command from forward switch 25A to reposition component 26 toward the second position 46 (arrow 44), controller 20 selectively provides PWM power 34 to motor 22, causing output shaft 28 to rotate in the second rotation direction 32, which repositions component 26 toward the second position 46 (arrow 44). When component 26 is in the second position 46 and / or when controller 20 receives a command from forward switch 25A to terminate the movement of component 26, controller 20 terminates the PWM power 34 to motor 22. Additionally, when component 26 is in the second position 46 and controller 20 receives a command from reverse switch 25B to reposition component 26 toward the first position 42, controller 20 selectively provides PWM power 34 to motor 22, causing output shaft 28 to rotate in the first rotation direction 30, which repositions component 26 toward the first position 42 (arrow 40). When component 26 is in the first position 42 and / or when controller 20 receives a command from reverse switch 25B to terminate the movement of component 26, controller 20 terminates the PWM power 34 to motor 22.

[0064] Figure 2 Power curve 34A in the diagram shows an exemplary graph of the amount of PWM power 34 supplied by controller 20 to motor 22 when component 26 is repositioned from a first position 42 at time A to a second position 46 at time B. Figure 2 As shown, the amount of PWM power 34 at a specific time is described as time t. n instantaneous power P at the point n As is known in the art, the amount of PWM power 34 supplied to the motor 22 is the electrical power generated by a PWM signal directly related to the percentage of the PWM duty cycle 52. More specifically, the percentage of the PWM duty cycle 52 is the ratio of the duration of the full-power pulse of the PWM power 34 supplied to the motor 22 to the entire pulse width modulation (PWM) interval period. A 100% percentage of the PWM duty cycle 52 indicates that full power is supplied to the motor 22. The amount of PWM power 34 supplied to the motor 22 is generally proportional to the amount of force or torque provided by the motor 22 and is related to the percentage of the PWM duty cycle 52 supplied to the motor 22.

[0065] refer to Figure 1 and Figure 2 The power curve 34A initially shows the motor 22 de-energized while component 26 is in the first position 42. When controller 20 receives a command from forward switch 25A, controller 20 provides a low amount of PWM power 34 to motor 22 at time A (i.e., a low percentage of PWM duty cycle 52). Next, controller 20 ramps up the amount of PWM power 34 over time by increasing the percentage of PWM duty cycle 52, as shown in portion 54 of region C. Referring to portion 56 of region D of power curve 34A, controller 20 continuously provides a high amount of PWM power 34 to motor 22 (i.e., a high percentage of PWM duty cycle 52) until controller 20 detects component 26 approaching the second position 46. In some embodiments, controller 20 may base its power supply on Hall effect pulses 38 received by controller 20 (…). Figure 3 The amount of PWM power 34 supplied to motor 22, the amount of time since the initial supply of PWM power 34 to motor 22, and the magnitude of the current 58 drawn by motor 22. Figure 6 The controller 20 detects that component 26 is approaching the second position 46, as is known in the art. When component 26 approaches the second position 46, the controller 20 reduces the amount of PWM power 34 supplied to the motor 22 by decreasing the percentage of the PWM duty cycle 52, as shown in part 60 of region E. Next, when the controller 20 detects that component 26 is in the second position 46, the controller 20 terminates the PWM power 34 to the motor 22 at time B.

[0066] exist Figure 3 and Figure 5 The Hall effect pulse 38 (hereinafter referred to as the "HE pulse") received by the controller 20 is shown in more detail. Figure 3 and Figure 5 An exemplary HE pulse 38 received over time is shown, where the Y-axis represents voltage (volts) and the X-axis represents the time unit (seconds). Alternatively, without changing the scope of the invention, the time unit may be milliseconds, a count of sampling times, etc. Time value t n t n+1 "etc." refers to a specific time recorded by controller 20, and does not necessarily correspond to consecutive units of time. In contrast, Figure 3 and Figure 5 Small time intervals on the X-axis t n , t n+1 …consisting of small time intervals corresponding to a selected number of time units t is separated. It should be understood that a small time interval... t may include one or more sampling time counts (seconds), one or more milliseconds, etc., without changing the scope of the invention.

[0067] Reference Figure 3 The HE pulse 38 received from the Hall effect sensor 36 includes a high-voltage portion 64 followed by a low-voltage portion 66. Each high-voltage portion 64 includes a leading edge 68 where the voltage amplitude transitions from low voltage 70 to high voltage 72 and a trailing edge 74 where the voltage amplitude transitions from high voltage 72 to low voltage 70. The controller 20 adjusts the pulse for each small time interval. The number of HE pulses 38 received by t is counted, and the rotational speed 76 of the output shaft 28 is calculated. Figure 4 As is known in the art, an exemplary method for calculating the rotational speed 76 is based on each small time interval. The number of the leading edges 68 of the received HE pulse 38 is counted.

[0068] Reference Figure 5 The controller 20 also monitors large consecutive time intervals. T (which is greater than the small time interval) The controller 20 counts the number of HE pulses 38 received in each large time interval. The second rotational speed 76' is calculated by the number of HE pulses 38 received in T. Figure 4 Large time intervals T is the small time interval. Multiples of t. In one exemplary embodiment, a small time interval. t = 10 sampling time counts, and large time intervals Each sampling time is counted. More specifically, over long time intervals... T n The number of HE pulses 38 received within the small time interval is equal to the number of HE pulses 38 received within the small time interval. t n , t n+1 , t n+2 and t n+3 The number of HE pulses 38 received internally.

[0069] Reference Figure 3 Another method for calculating the rotational speed 76 is based on calculating the time difference DT between the consecutive leading edges 68A, 68B, and 68C of the HE pulse 38, which is typically described as HE Delta_T. HE Delta_T is measured in units of time (e.g., seconds, milliseconds, sampling time counts, etc.). See reference... Figure 3 The first frontier 68A appeared at time t n At that point, and the second frontier 68B appeared at time t. n+1 At, where t n and t n+1 This represents the actual time value. It pertains to the time difference DT. n HE Delta_T is calculated as time t n With time t n+1 The difference between them, i.e., DT n =t n+1 -t n In addition, HE Delta_T n+1 The value is the time difference DT between the second leading edge 68B and the third leading edge 68C. n+1 The value of HE Delta_T is proportional to the reciprocal of the rotational speed of the output shaft 28, which is 76.

[0070] Figure 4 This illustrates when component 26 responds to the PWM power 34 supplied to motor 22. Figure 2 An exemplary graph showing the rotational speed 76 of the output shaft 28 as the quantity of the output shaft 28 is repositioned from the first position 42 at time A to the second position 46 at time B. Figure 4 In this diagram, the x-axis represents time (seconds), and the y-axis represents rotational speed (RPM). Additionally, the rotational speed at a specific time point (76) is typically described as time t. n instantaneous velocity S at point n . Reference Figure 1 , Figure 2 The power curves in 34A and Figure 4In speed curve 76A, initially, due to the power outage of motor 22, the rotational speed 76 is zero at time A. Referring to speed curve 76A, the rotational speed 76 gradually increases in part 78, which corresponds to... Figure 2 Section 54 (region C) of the output shaft 28. The rotational speed 76 of the output shaft 28 is approximately stable in section 80, which corresponds to... Figure 2 Part 56 (region D) of the output shaft 28. Additionally, the rotational speed 76 of the output shaft 28 decreases rapidly in part 82, which corresponds to... Figure 2 Part 60 (Region E) of the middle.

[0071] Figure 6 This shows the amount of PWM power 34 supplied to motor 22 in response to component 26. Figure 2 An exemplary graph showing the amplitude of the current 58 drawn by the motor 22 when the motor is repositioned from the first position 42 at time A to the second position 46 at time B. Figure 6 The x-axis represents time (seconds), and the y-axis represents current (amperes). Additionally, the magnitude of the current 58 at a specific time is typically described as time t. n Instantaneous current A at the location n . refer to Figure 6 In the current curve 58A, initially, due to the de-energization of motor 22, the amplitude of current 58 is zero. Controller 20 begins to supply PWM power 34 to motor 22 at time A. Subsequently, in response to the PWM power 34 being supplied to motor 22, the amplitude of current 58 rapidly increases (part 86), reaching a surge peak 88, and then the amplitude of current 58 rapidly decreases (part 90). Parts 86 and 90 of current curve 58A appear in time period 92 and are generally described as surge currents 86 and 90. Next, the amplitude of current 58 stabilizes approximately in part 94, corresponding to part 56 in region D (…). Figure 2 In this process, motor 22 is supplied with a stable amount of PWM power 34, and it is assumed that the frictional force and torque resisting the rotation of output shaft 28 are constant. Time period 96 includes the current 58 supplied in section 94, and is generally described as a stabilizing current 94. Next, as component 26 repositions towards the second position 46 and encounters the front stop 50, the amplitude of current 58 rapidly increases (section 98). When the amplitude of current 58 reaches a predetermined maximum current value 100, controller 20 terminates the PWM power 34 to motor 22, causing the amplitude of current 58 to rapidly drop to zero (section 102). Time period 104 includes section 98, which is generally described as a stall current 98. Additionally, section 98 roughly corresponds to Figure 2 Part 60 of region E. Figure 6 The maximum hardware current C is also shown in the diagram. maxIf the amplitude of the current 58 is equal to or greater than the maximum hardware current C max Then the controller 20 terminates the PWM power 34 of the motor 22.

[0072] Figure 7 An exemplary graph showing the amplitude of the voltage 106 supplied to the motor 22 as a function of time is shown, which is illustrated as voltage curve 106A. Figure 7 The x-axis represents time (seconds), and the y-axis represents voltage (volts). Additionally, the magnitude of the voltage 10⁶ at a specific time is typically described as the voltage at time t. n instantaneous voltage V at point n Referring to voltage curve 106A, voltage 106 is supplied to motor 22 from time A to time B in section 108. At time B, controller 20 stops supplying voltage 106 to motor 22 (shown as section 110), which causes the amplitude of voltage 106 to drop to zero.

[0073] When controller 20 detects an adverse condition, controller 20 may adjust and / or terminate the amplitude of the PWM power 34 to motor 22. An example of an adverse condition is when the amplitude of the current 58 drawn by motor 22 ( Figure 6 () greater than the maximum hardware current C max Typically, when the amplitude of the current 58 drawn by the motor 22 exceeds the maximum hardware current C... max At that time, the controller 20 will terminate the PWM power 34 of the motor 22.

[0074] A second example of an unfavorable situation is when the output shaft 28 rotates at a speed of 76 rpm within the target range of 112 rpm. Figure 4 When the speed of the output shaft 28 changes outside the target range 112, the controller 20 can adjust the amount of PWM power 34 supplied to the motor 22 to maintain the speed 76 of the output shaft 28 within the target range 112. This is generally described as speed control. As is known in the art, the load on the motor 22 is affected by friction in certain components of the seat assembly 10 (e.g., gearbox 24, seat rail 18, etc., as non-limiting examples). Additionally, the load on the motor 22 is affected by the weight of the occupant when seated on the seat cushion 16. It should be understood that the controller 20 may include speed control or may lack speed control without changing the scope of the invention. It should be understood that the target range 112 can be adjusted based on the operating parameters of the motor 22 and other parameters without changing the scope of the invention.

[0075] A third example of an adverse condition is when an object (not shown) restricts the movement of part 26 between a first position 42 and a second position 46 (this is often described as a “pinch condition”). Controller 20 includes an anti-pinch detection system 12 that detects whether part 26 encounters an obstacle (i.e., a “pinch condition”) when part 26 is repositioned.

[0076] Figure 9 An exemplary motor control flowchart 116 is shown according to one embodiment of the present invention, which includes speed control and an anti-pinch detection system 12. (Refer to...) Figure 9 The motor control flowchart 116 begins at step 118. Next, in response to the controller 20 receiving a command from one of the forward switch 25A and the reverse switch 25B for repositioning the component 26, the controller 20 begins to provide a PWM duty cycle 52 to the motor 22 (step 120). Next, in step 122, the controller 20 continues to provide the PWM duty cycle 52 to the motor 22 based on predetermined operating parameters, while monitoring and storing in memory parameters related to the HE pulse 38 received from the Hall effect sensor 36. Figure 3 and Figure 5 The amplitude of the current 58 drawn by the motor 22 ( Figure 6 ), the voltage supplied to motor 22 is 106 ( Figure 7 ) and the percentage of the PWM duty cycle 52 provided by controller 20 to motor 22 ( Figure 2 Related to this. In step 124, controller 20 determines whether a clamping condition has been detected when controller 20 provides PWM duty cycle 52 to motor 22. The clamping condition is detected by anti-clamping detection system 12, which is described in more detail below. If a clamping condition is detected, controller 20 terminates PWM duty cycle 52 to motor 22 (step 126) and ends motor control flowchart 116 (step 128).

[0077] If controller 20 does not detect a clamping condition (step 124), then controller 20 next determines whether the rotational speed 76 of output shaft 28 is below the target range 112 (step 130). In step 130, if controller 20 determines that the rotational speed 76 is not below the target range 112, then controller 20 proceeds to step 132. In step 130, if controller 20 detects that the rotational speed 76 is below the target range 112, then controller 20 increases the amount of PWM power 34 supplied to motor 22 by increasing the percentage of PWM duty cycle 52 (step 134), and proceeds to step 132.

[0078] Next, in step 132, controller 20 determines whether the rotational speed 76 is higher than the target range 112. If controller 20 determines in step 132 that the rotational speed 76 is not higher than the target range 112, then controller 20 proceeds to step 136. If controller 20 determines in step 132 that the rotational speed 76 is higher than the target range 112, then controller 20 reduces the amount of PWM power 34 supplied to motor 22 by reducing the percentage of the PWM duty cycle 52 (step 138), and proceeds to step 136.

[0079] In step 136, controller 20 determines whether the amplitude of current 58 is equal to or greater than the maximum hardware current C. max If controller 20 determines that the amplitude of current 58 is equal to or greater than the maximum hardware current C. max Then, controller 20 continues to step 126 and terminates at the PWM duty cycle 52 of motor 22. In step 136, if controller 20 determines that the amplitude of current 58 is less than the maximum hardware current C... max Then controller 20 continues to step 140.

[0080] Next, in step 140, controller 20 determines whether component 26 is in the desired position (also typically described as the end of the stroke) between the first position 42 and the second position 46. If controller 20 determines that component 26 is in the desired position between the first position 42 and the second position 46 (step 140), controller 20 proceeds to step 126 and terminates at PWM duty cycle 52 for motor 22. If controller 20 determines that component 26 is not in the desired position between the first position 42 and the second position 46 (step 140), controller 20 returns to step 122 and continues to supply PWM duty cycle 52 to motor 22. It should be understood that the motor control flowchart 116 can be varied without changing the scope of the invention.

[0081] Controller 20 also includes a sequence detection process 142, which in Figure 10 The sequence flow diagram 142A is shown. The sequence detection process 142 includes an anti-pinch detection system 12 and additional functions further described below. It should be understood that the sequence detection process 142 can be varied without changing the scope of the invention. See also... Figure 10The sequence detection process 142 begins at step 144 of the sequence flowchart 142A. Controller 20 monitors to determine whether the vehicle ignition device (not shown) is on (step 145). When controller 20 detects that the vehicle ignition device is on, controller 20 proceeds to step 146. Next, in step 146, controller 20 initiates the P1 NVRAM process 147. The P1 non-volatile random access memory (NVRAM) process 147 handles all data readout processes, data recording, counting ignition cycles, updating health status information, and counting the number of times the motor 22 is actuated. In addition, the P1 NVRAM process 147 records the peak occurrences of PWM power 34 and current 58. The sequence detection process 142 continues to execute during the vehicle's ignition device being on. The P1 NVRAM process 147 is also configured to identify potential motor 22 problems related to aging or overuse scenarios. As described in more detail below, the P1 NVRAM process 147 records overcurrent events 148 ( Figure 15 ) and the average current of 150 drawn by motor 22 during steady state. Figure 12 The detection statistics (not shown) relate to changes in the motor's motion. These statistics can be used for short-term and / or long-term compensation. Furthermore, summarizing the detection statistics over time captures the health status of the motor's motion and provides additional insights for future service.

[0082] P1 NVRAM process 147 ( Figure 10 One implementation of step 146 includes Figure 11 The ignition counter 152 shown is used to track the number of times the motor 22 is operated. Furthermore, the ignition counter 152 tracks the movement of the motor 22 and the points in time at which some data is stored in memory. Figure 8 As shown, the ignition counter 152 stores the operation value 154 in the ignition memory 156 in a 16-bit format, as is known in the art.

[0083] exist Figure 11 The ignition counter 152 is illustrated in more detail in the counter flowchart 152A shown. (Refer to...) Figure 11Ignition counter 152 begins at step 158 of counter flowchart 152A. Next, controller 20 determines whether vehicle ignition has been recorded (step 160). In step 160, if vehicle ignition has been recorded, controller 20 returns to step 158. However, in step 160, if vehicle ignition has not been recorded, controller 20 proceeds to step 162. Next, in step 162, controller 20 determines whether any of the motors 22 are active. In step 162, if controller 20 determines that a motor 22 is not active, controller 20 returns to step 158. However, in step 162, if controller 20 determines that at least one motor 22 is active, controller 20 proceeds to step 164. Next, in step 164, the controller 20 reads the current operation value 154 from the ignition memory 156, in step 166 increments the operation value 154, in step 168 writes the new operation value 154 into the ignition memory 156, and in step 170 proceeds to the end of the counter flowchart 152A.

[0084] Reference Figure 12 According to one embodiment of the present invention, P1 NVRAM process 147 ( Figure 10 Step 146) also includes an average current monitor 172. The average current monitor 172 calculates the current 58 drawn by the motor 22 over a time range of 96 (i.e., when the amplitude of the drawn current 58 is in a stable state, for example, by…). Figure 13 The average current value of 150 during the period shown in region 174. Region 174 roughly corresponds to... Figure 6 and Figure 13 The current curve shown is portion 94 of 58A. (Refer to...) Figure 14 The expected amplitude of current 58 varies from zero 176 to a predetermined overcurrent value 178. The amplitude range of current 58 is divided into nonlinear current intervals 179, where each current interval 179 has a corresponding lower current limit 180 and a corresponding upper current limit 182. Figure 14 In the embodiment shown, the current range 179 is divided into ranges 1 to 9. The controller 20 determines which current range 179 corresponds to the detected average current 150 value.

[0085] Figure 17 An exemplary memory storage device 184 is shown for storing the detected current interval 179 and the current ignition counter 186 in a 16-bit format. The memory storage device 184 includes the current ignition counter 186 when calculating the average current value 150, a verification code 188, and the detected current interval 179. The verification code 188 is an authentication strategy used to verify the detected current interval 179.

[0086] exist Figure 12The average current monitor 172 is described in more detail in the current flow diagram 172A shown. (Refer to...) Figure 12 The average current monitor 172 begins at step 192 of the current flow chart 172A. Next, in step 194, the controller 20 determines whether the motor 22 is active. If the controller 20 determines in step 194 that the motor 22 is not active, the controller 20 proceeds to step 196. In step 196, the controller 20 determines whether a new average current 150 exists. If the controller 20 detects that no new average current 150 exists in step 196, the controller 20 proceeds to the end of the current flow chart 172A (step 198). If the controller 20 detects the existence of a new average current 150 in step 196, the controller 20 combines the new average current 150 for this ignition cycle and determines a current range 179 based on the combined average current 150 (step 200). Next, in step 202, the controller 20 manages the verification codes and arrays in memory. Controller 20 stores the average current value 150 and / or current range 179 as a shift array, and shifts the stored values ​​when a higher current range 179 is detected. After controller 20 completes step 202, controller 20 proceeds to the end of current flow diagram 172A (step 198).

[0087] However, in step 194, if the controller 20 determines that the motor 22 is active, the controller 20 proceeds to step 206 of the current flow diagram 172A. In step 206, the controller 20 determines whether to read data from the memory. If the controller 20 determines to read data from the memory in step 206, the controller 20 proceeds to step 208. However, if the controller 20 determines that data is not read from the memory (step 206), the controller 20 obtains the current range 179 to be monitored through memory initialization (step 210) and proceeds to step 208. In step 208, the controller 20 determines whether to ignore surge currents 86 and 90 (…). Figure 13In step 208, if controller 20 determines that inrush currents 86 and 90 are not ignored, controller 20 proceeds to the end of current flow diagram 172A (step 198). However, if controller 20 determines that inrush currents 86 and 90 are ignored in step 208, controller 20 proceeds to step 211. In step 211, controller 20 determines whether there is a sudden change in the amplitude of current 58 or whether clamp detection is in progress. If controller 20 determines that there is a sudden change in the amplitude of current 58 or detects that clamp detection is in progress (step 211), controller 20 proceeds to the end of current flow diagram 172A (step 198). However, if controller 20 detects that a sudden change in the amplitude of current 58 is not detected and clamp detection is not in progress in step 211, controller 20 calculates a new average current 150 value in step 212 and proceeds to the end of current flow diagram 172A (step 198).

[0088] Reference Figure 16 According to one embodiment of the present invention, P1 NVRAM process 147 ( Figure 10 Step 146) also includes an overcurrent monitor 214. (See reference...) Figure 15 When the amplitude of current 58 exceeds the overcurrent threshold 216, the overcurrent monitor 214 detects that an overcurrent event 148 has occurred. For each overcurrent event 148, the overcurrent monitor 214 tracks the difference between the detected overcurrent peak value 217 and the overcurrent threshold 216. The overcurrent monitor 214 also tracks the amount of time 218 between the current 58 exceeding the overcurrent threshold 216 and the controller 20 shutting off the PWM power 34 to the motor 22. The overcurrent monitor 214 provides an indication of the controller 20's response in the event of stall conditions and / or clamping conditions. The overcurrent monitor 214 points to... Figure 15 Region 220 of the current curve 58A. Specifically, region 220 is defined by the time range during which the amplitude of current 58 is greater than the overcurrent threshold 216 and equal to or less than the overcurrent peak 217. Furthermore, the overcurrent monitor 214 evaluates the overcurrent height 224 as the difference between the overcurrent peak 217 and the overcurrent threshold 216. The amount of time 218 during which the amplitude of current 58 is above the overcurrent threshold 216 is alternatively described as the overcurrent width 218.

[0089] In addition, the overcurrent monitor 214 monitors each overcurrent event 148 ( Figure 15 Record the location range 226 where stall and / or clamping occurred. Figure 1 Position interval 226 corresponds to an approximate position between the first position 42 and the second position 46. Furthermore, the overcurrent monitor 214 calculates the position verification code 227 (…). Figure 19(to verify the recurrence of stall conditions and / or clamping conditions).

[0090] exist Figure 16 The overcurrent monitor 214 is described in more detail in the overcurrent flowchart 214A shown. (Refer to...) Figure 16 Overcurrent monitor 214 begins at step 228 of overcurrent flowchart 214A. Next, in step 230, controller 20 determines whether motor 22 is activated. If controller 20 determines in step 230 that motor 22 is not activated, controller 20 proceeds to step 232. In step 232, controller 20 determines whether a new overcurrent event 148 has occurred. Figure 15 In step 232, if the controller 20 detects that no new overcurrent event 148 has occurred, the controller 20 proceeds to the end of the overcurrent flowchart 214A (step 234). In step 232, if the controller 20 detects that a new overcurrent event 148 has occurred, then in step 236, the controller 20 combines the overcurrent event 148 with the data stored in the overcurrent memory 235. Figure 18 The old data in ) is compared and combined. Next, in step 240, the controller 20 manages the location verification code 227 ( Figure 19 ) and the array in the overcurrent memory 235 ( Figure 18 After the controller 20 manages the array in the overcurrent memory 235 (step 240), the controller 20 proceeds to the end of the overcurrent flowchart 214A (step 234).

[0091] exist Figure 18 An exemplary storage format for the overcurrent memory 235 is shown in the figure. (Refer to...) Figure 18 The overcurrent monitor 214 stores data in a 32-bit format, where bits 0 to 9 store the amount of PWM power 34 supplied to the motor 22, bits 10 to 15 store the overcurrent width 218 in multiples of 10 ms, bits 16 to 20 store the overcurrent height 224 in multiples of 0.5 amperes, and bits 21 to 31 store the ignition counter value 186. (See reference...) Figure 19 The overcurrent monitor 214 stores additional data in PWM memory 244 in 16-bit format, where bits 0 to 3 store the current position interval 226 when the overcurrent event 148 occurs. Furthermore, the overcurrent monitor 214 stores a position verification code 227 in bits 4 and 5. Additionally, the overcurrent monitor 214 stores the PWM power 34 supplied to the motor 22 when the overcurrent event 148 occurs. Figure 2The PWM interval 246 is determined based on the percentage of the PWM duty cycle 52. Furthermore, the overcurrent monitor 214 determines the PWM verification code 248 to confirm the detected PWM interval 246. Next, the controller 20 stores the PWM interval 246 and the PWM verification code 248 in bits 6 to 9 and bits 10 to 11 of the PWM memory 244, respectively.

[0092] Reference Figure 16 In step 230 of the overcurrent flowchart 214A, if the controller 20 detects that the motor 22 is active, the controller 20 determines whether data has been read from the overcurrent memory 235 (step 250). If the controller 20 determines in step 250 that data has been read from the overcurrent memory 235, the controller 20 proceeds to step 252. However, if the controller 20 determines that data has not been read from the overcurrent memory 235 (step 250), the controller 20 initializes data related to the location interval 226 to be monitored and the overcurrent event 148 from the memory (step 254) and proceeds to step 252. Next, in step 252, the controller 20 determines the surge currents 86 and 90 (…). Figure 15 Whether the surge current 86 and 90 have been ignored. In step 252, if the controller 20 determines that the surge current 86 and 90 have not been ignored, the controller 20 proceeds to the end of the overcurrent flowchart 214A (step 234). However, in step 252, if the controller 20 determines that the surge current 86 and 90 have been ignored, the controller 20 determines whether the detected current 58 is higher than the overcurrent threshold 216 (step 256). If the controller 20 determines that the current 58 is not higher than the overcurrent threshold 216 (step 256), the controller 20 proceeds to the end of the overcurrent flowchart 214A (step 234). However, if the controller 20 detects that the current 58 is higher than the overcurrent threshold 216 (step 256), in step 258 the controller 20 calculates a new average current 150 and proceeds to the end of the overcurrent flowchart 214A (step 234).

[0093] like Figure 10 As shown in the sequence flowchart 142A, after the controller 20 initiates the P1 NVRAM process 147 (step 146), the controller 20 initiates the P2 Hall effect process 260 (step 262). (Refer to...) Figure 3 and Figure 5 The P2 Hall effect process 260 receives the HE pulse 38 from the Hall effect sensor 36 in response to the rotation of the output shaft 28. The P2 Hall effect process 260 calculates the time difference DT between the consecutive leading edges 68A, 68B, and 68C of the HE pulse 38. n (Typically described as HE Delta_T). Furthermore, the P2 Hall effect process 260 for each small time interval... The number of HE pulses 38 received is counted. Next, the P2 Hall effect process 260 is performed for each small time interval. t. Calculate the first rotational speed 76 based on the number of received HE pulses 38. The P2 Hall effect process 260 also performs calculations for each large time interval. The number of HE pulses 38 received by T is counted. Next, the P2 Hall effect process 260 is performed for each large time interval. T, calculate the second rotational speed 76' based on the number of received HE pulses 38. Figure 4 The rotational speeds 76 and 76', calculated over time using the P2 Hall effect process 260, are shown.

[0094] Furthermore, the P2 Hall effect process 260 is for each consecutive small time interval. t monitors the amount of electrical power 263 supplied to motor 22 over time, such as Figure 5 As shown in the diagram. Additionally, the electrical power 263 is optionally based on a percentage of the PWM power 34 and / or the PWM duty cycle 52 supplied to the motor 22. The P2 Hall effect process 260 optionally filters or otherwise adjusts the value of the PWM power 34. Next, the P2 Hall effect process 260 is performed for each consecutive small time interval. t calculates the median-filtered power value 264. Optionally, the P2 Hall effect process 260 is performed for each consecutive large time interval. T calculates the power value 264' after the second median filter. The P2 Hall effect process 260 continues until it is terminated by the controller 20.

[0095] like Figure 10 As shown in the sequence flowchart 142A, after controller 20 initiates the P2 Hall effect process 260 (step 262), controller 20 initiates the P3 power calculation 266 (step 268). (Refer to...) Figure 22 The P3 power calculation 266 calculates the electrical power 270 supplied to the motor 22 and the mechanical power 272 applied by the motor 22 over time, as further described below. The P3 power calculation 266 continues to operate until it is terminated by the controller 20.

[0096] P3 power calculation 266 is based on the voltage 106 supplied to motor 22. Figure 7 and Figure 20 ) and current 58 ( Figure 6 and Figure 21 To calculate the electrical power 270 ( Figure 22 ). Figure 20The image depicts an enlarged view of the voltage 106 (volts) supplied to the motor 22 over time (seconds). Furthermore, in... Figure 21 The diagram depicts an enlarged view of the current 58 (Amperes) drawn by motor 22 over time (seconds). Power calculation 266 on page P3 determines the current at time t. n The instantaneous value of voltage V at point 106 n and the instantaneous value of current 58 A n Next, the P3 power calculation 266 will be performed by considering time t. n instantaneous value V at point n and A n Multiply to determine the electric power 270 at time t n instantaneous value EP at the location n (Right now, P3 power calculation 266 for each time value t n t n+1 ...repeatedly calculate the electrical power 270 until controller 20 terminates the P3 power calculation 266.

[0097] The P3 power calculation 266 also calculates the mechanical power 272 applied by the motor 22 based on an estimate of the force and / or torque 274 applied by the motor 22 and based on the rotational speed 76 of the output shaft 28. Figure 22 ). Reference Figure 2 and Figure 23 P3 power calculation 266 is based on time t n The instantaneous value P of the PWM power 34 supplied to motor 22 n To estimate at time t n The instantaneous value MF of the force and / or torque 274 applied by the electric motor 22 n . Figure 4 It shows that at time t n The instantaneous value S of the rotational speed of the output shaft 28 at point 76 n The instantaneous value S n It is calculated by the P2 Hall effect process 260 based on the HE pulse 38 received by the controller 20. During the P3 power calculation 266, the controller 20 calculates the instantaneous mechanical force MF. n Multiply by time t n instantaneous velocity S at point n To calculate the instantaneous value MP of mechanical power 272. n .

[0098] In some implementations, P3 power calculation 266 is based on the time difference DT of HE Delta_T. n Instead of instantaneous velocity S n To determine the instantaneous value MP of mechanical power 272. n ( Figure 22HE Delta_T is proportional to the reciprocal of the rotational speed of the output shaft 28, which is 76. Figure 24 The image shows a magnified view of HE Delta_T as a function of time (seconds). (See reference...) Figure 3 and Figure 24 At time t n Time difference DT n At time t n The time interval between the consecutive leading edges 68A and 68B of the HE pulse 38 recorded at point 38. Figures 22 to 24 In the embodiment shown, P3 power calculation 266 calculates the power over time t. n instantaneous value MF at point n and DT n Multiplication to determine time t n The instantaneous value of the mechanical power at point 272 MP n (Right now, P3 power calculation 266 for each time value t n t n+1 ...repeatedly calculate mechanical power 272 until controller 20 terminates P3 power calculation 266.

[0099] like Figure 10 As shown, after controller 20 initiates P3 power calculation 266 (step 268), controller 20 initiates P4 region identifier 276 in step 278. P4 region identifier 276 continues to run until terminated by controller 20. (See reference...) Figure 4 The P4 region identifier 276 determines whether the movement of component 26 is associated with region C, region D, or region E of the speed curve 76A. When the controller 20 includes speed control, the rotational speed 76 follows a predictable trajectory as component 26 moves from a first position 42 at time A to a second position 46 at time B. The sum of all forces (or torques) within the seat assembly 10 includes the driving force applied by the motor 22 via the gearbox 24 or gear train, frictional forces associated with the various components in the seat assembly 10, forces caused by gravity, etc. Speed ​​control in the controller 20 assists in achieving the desired speed 76 by adjusting the amplitude of the PWM power 34 supplied to the motor 22.

[0100] Figure 4An exemplary speed trajectory is shown, illustrating the change in rotational speed 76 as component 26 moves between a first position 42 and a second position 46. More specifically, component 26 is stationary at time A. Next, controller 20 provides ramped PWM power 34 (part 78) to motor 22, thereby accelerating component 26 from its stationary position. Then, in response to a substantially stable amplitude of the PWM power 34 provided by controller 20 to motor 22, component 26 operates at a substantially stable rotational speed 76 for a period of time (part 80). Controller 20 adjusts the amplitude of the PWM power 34 provided to motor 22 to maintain rotational speed 76 within a target range 112. Figure 4 During part 80, component 26 moves at a roughly constant rotational speed 76 because the driving force applied by motor 22 roughly balances the forces caused by friction and gravity. When controller 20 determines that component 26 is approaching the second position 46, controller 20 ramps down the amplitude of PWM power 34, which causes motor 22 to reduce the rotational speed 76 of output shaft 28 until component 26 stops at the second position 46.

[0101] Figure 4 The velocity trajectories shown include predictable regions C, D, and E, which are substantially associated with portions 78, 80, and 82 of the velocity curve 76A, respectively. More specifically, region C is defined by portion 78, where the rotational speed 76 increases over time. Region D is defined by portion 80, where the rotational speed 76 remains substantially within the target range 112 over time. Additionally, region E is defined by portion 82, where the rotational speed 76 decreases over time.

[0102] When controller 20 includes speed control, P4 zone identifier 276 determines the current zone C, D, E based on the calculated position of component 26 and a setpoint based on the target speed. If controller 20 lacks speed control, P4 zone identifier 276 determines the current zone C, D, E by monitoring the rotational speed 76 calculated based on the HE pulse 38 received by controller 20. The calculated rotational speed 76 is determined by P2 Hall effect process 260.

[0103] The P4 region identifier 276 selects region C when the rotational speed 76 increases over time. As long as the rotational speed 76 continues to increase over time, the P4 region identifier 276 will maintain the selected region C. Conversely, the P4 region identifier 276 selects region E when the rotational speed 76 decreases over time. As long as the rotational speed 76 has a decreasing trend over time, the P4 region identifier 276 will maintain the selected region E. However, whenever the P4 region identifier 276 detects an extremely transient situation (e.g., a rapid transition between region C and region E), the P4 region identifier 276 will select region D. The P4 region identifier 276 will also select region D when the rotational speed 76 is within the target range 112 or when the controller 20 provides stable speed control.

[0104] like Figure 10 As shown in the sequence flowchart 142A, after controller 20 starts P4 region identifier 276 (step 278), controller 20 starts P5 event analysis 280 in step 282. (Refer to...) Figure 25 and Figure 26 P5 event analysis 280 controls enabler L and analyzes the electrical power 270 and HE Delta_T that change over time. Figure 26 An exemplary P5 flowchart 284 for P5 event analysis 280 is shown. P5 event analysis 280 begins at step 286 of P5 flowchart 284 and proceeds to step 288. Without departing from the scope of the invention, P5 event analysis 280 may optionally initiate step 286 of P5 flowchart 284 in each vehicle ignition cycle, each time the electric motor 22 runs, and / or periodically based on a predetermined time period or other criteria. For example, P5 event analysis 280 may initiate step 286 of P5 flowchart 284 when P4 region identifier 276 selects region D.

[0105] Next, in step 288 of flowchart 284, P5 event analysis 280 monitors electrical power 270 and HE Delta_T, and determines whether both are within their respective stable ranges. Optionally, P5 event analysis 280 determines that electrical power 270 and HE Delta_T may be within their respective stable ranges based on region D selected by P4 region identifier 276. If electrical power 270 and HE Delta_T are within their stable ranges, P5 event analysis 280 then determines the stable range at time t. start The enabler L is activated, a new temporary buffer is opened, and the process proceeds to step 290. Next, in step 290, P5 event analysis 280 receives time t. start The first value of the electrical power 270, Pwr(n), and the first value of HE Delta_T, DT(n), are obtained, and the process proceeds to step 292. After receiving the values ​​of Pwr(n) and DT(n), in step 292, the P5 event analysis 280 sets the variables. Setting variables Setting variables And set variables Then proceed to step 294. In step 294, P5 event analysis 280 stores the current values ​​of Pwr(n) and DT(n) in a temporary buffer and proceeds to step 296. (See reference...) Figure 25The current values ​​of the electrical power 270, Pwr(n), and HE Delta_T, DT(n), within time blocks 298 and 300 are stored in a temporary buffer when enabler L is activated. Next, in step 296, P5 event analysis 280 sets variables. Set variables Set variables and set variables The process proceeds to step 302. In step 302, P5 event analysis 280 receives new values ​​for Pwr(n) and DT(n) and proceeds to step 304. In step 304, P5 event analysis 280 sets variables. Set variables Set the variable DT_Max(n) = max(DT_Max(n-1), DT(n)), and set the variable... Then proceed to step 306. Next, in step 306, P5 event analysis 280 determines whether... , where TH is a predetermined energy threshold. If Then the power 270 has become unstable, and P5 event analysis 280 proceeds to step 308.

[0106] However, in step 306, if P5 event analysis 280 determines PwrMax(n) - PwrMin(n)... If TH is reached, then the power 270 is stable, and P5 event analysis 280 proceeds to step 310. In step 310, P5 event analysis 280 determines whether... Where TR is the predetermined time threshold. If P5 event analysis 280 determines... If HE Delta_T has become unstable, then P5 event analysis 280 proceeds to step 308. However, if P5 event analysis 280 determines... If HE Delta_T is stable, then P5 event analysis 280 proceeds to step 312. In step 312, P5 event analysis 280 determines whether a timeout has occurred. A timeout can occur when the vehicle ignition is turned off, when the electric motor 22 is deactivated, or after a predetermined time period (these are non-limiting examples). If, in step 312, P5 event analysis 280 determines that a timeout has occurred, then P5 event analysis 280 proceeds to step 308. However, if, in step 312, P5 event analysis 280 determines that no timeout has occurred, then P5 event analysis 280 returns to step 294 and continues with P5 flowchart 284.

[0107] exist Figure 26 In step 308, P5 event analysis 280 at time t endThe enabler L is terminated and the process proceeds to step 314. In step 314, P5 event analyzer 280 closes the temporary buffer. After completing step 314, P5 event analyzer 280 calculates the average value EP of Pwr(n) stored in the temporary buffer. ave (Step 316) Calculate the average value of DT(n) stored in the temporary buffer. ave (Step 318), and proceed to step 320. In step 320, P5 event analysis 280 will output an update to EP. ave and DT ave Stored in data buffer M, and proceed to the end of flowchart 284 (step 322).

[0108] like Figure 25 and Figure 27 As shown, P5 event analysis 280 will output the EP ave and DT ave The data is stored in data buffer M. The data stored in data buffer M is used by P5 event analysis 280 for health status assessment 326. Data buffer M comprises at least 10x2 elements, where each element comprises at least 8 bits. Preferably, when the first data buffer M is full, a second data buffer M' is reserved for storing a second series of output pairs EP. ave and DT ave .like Figure 27 As shown, when the new output is applied to EP ave and DT ave When data is added to data buffer M, it is shifted within data buffer M. When the first data buffer M is full or after N firing cycles, P5 event analyzer 280 opens the second data buffer M' and sets the new output to EP. ave and DT ave The data is stored in the second data buffer M'. The data stored in the data buffers M and M' is collected under various operating conditions (e.g., when different loads and / or different occupants are supported by the seat assembly 10).

[0109] Reference Figure 27 and Figure 28 When P5 Event Analysis 280 closes the first data buffer M and opens a new data buffer M', P5 Event Analysis 280 performs a health status assessment 326. During the health status assessment 326, P5 Event Analysis 280 adjusts the output in data buffer M against the EP. ave and DT ave Interrelated. Figure 28 The output pair (EP) in data buffer M is shown. ave DT ave The graph shows the average electrical power (EP) along the Y-axis.ave The quantity of HE Delta_T (i.e., DT) is plotted on the X-axis. ave The amount of data. Data points 328 and 330 are exemplary output pairs (EP) from data buffer M. ave DT ave P5 event analysis 280 calculates the first slope 332 from data points 328 and 330 from data buffer M. Data point 328 has the output pair (EP) in data buffer M. ave DT ave The minimum amount of the average HE Delta_T (DT) ave ) and the minimum amount of average electrical power (EP) ave This indicates a no-load condition. Under normal operating conditions, when an occupant is seated on the seat cushion 16, the load on the motor 22 increases, which in turn increases the average HE Delta_T (DT). ave And increased average power (EP) ave In some implementations, P5 event analysis 280 obtains load information from other vehicle systems, such as an occupant classification system (OCS). The first slope 332 of data points 328, 330 from data buffer M indicates the health status assessment 326 of the vehicle seat assembly 10.

[0110] After N ignition cycles (e.g., 5000 ignition cycles), P5 event analysis 280 closes the first data buffer M and opens the second data buffer M'. P5 event analysis 280 continues to store data in the second data buffer M' until the second data buffer M' is full. Next, P5 event analysis 280 performs another health status assessment 326 on the data in the second data buffer M'. During the health status assessment 326, P5 event analysis 280 makes the output in data buffer M' match the EP. ave and DT ave Interrelated. Figure 28 The output pair (EP) in data buffer M' is shown in the figure. ave DT ave Example data points 334 and 336. P5 event analysis 280 calculates a second slope 338 from data points 334 and 336 in data buffer M'. Data point 334 has an output pair (EP) in data buffer M'. ave DT ave The minimum amount of the average HE Delta_T (DT) ave ) and the minimum amount of average electrical power (EP) aveThe slope 332 indicates a no-load condition. The difference between the first slope 332 and the second slope 336 indicates a change in the health status of the seat assembly 10. Compared to the first slope 332, a change in the second slope 336 may indicate that the seat assembly 10 requires more energy to move the same amount of displacement, that the power of the motor 22 has decreased, or that the Hall effect sensor 36 may be defective, etc. (these are non-limiting examples). Furthermore, the health status assessment 326 may be performed periodically based on a fixed number of ignition cycles or based on the most recent health status. For example, the P5 event analysis 280 may adjust the time or number of ignition cycles before performing the next health status assessment 326 based on the results of the current health status assessment.

[0111] like Figure 10 As shown in the sequence flowchart 142A, after the controller 20 initiates P5 event analysis 280 (step 282), the controller 20 initiates P6 clamping detection 340 in step 342. P6 clamping detection 340 continues to run until it is terminated by the controller 20.

[0112] exist Figure 29 The P6 clamping detection 340 is described in more detail in the P6 flowchart 340A shown. The anti-clamping detection system 12 includes the P6 clamping detection 340, which monitors the current area identifier (C, D, or E) and selects one of several methods to detect a clamping condition. In step 344 of the P6 flowchart 340A, the controller 20 initiates the P6 clamping detection 340. Next, in step 345, in response to the PWM power 34 being supplied to the motor 22 (i.e., the motor 22 is turned on), the P6 clamping detection 340 receives a new area identifier (area C, D, or E) from the P4 area identifier 276. After receiving the current area identifier (C, D, or E) from the P4 area identifier 276 in step 345, the P6 clamping detection 340 determines in step 346 whether the current area is area C. If P6 clamping detection 340 determines that the current region is region C, then P6 clamping detection 340 proceeds to step 348, executing region C clamping detection 350. Figure 30The process proceeds to step 352. In step 352, P6 clamping detection 340 determines whether the area identifier has changed or whether the motor 22 has been turned off. If the area identifier has not changed and the motor 22 is still on, P6 clamping detection 340 returns to step 348 and continues to run area C clamping detection 350. However, if a change in the area identifier or the motor 22 is turned off is detected in step 352, P6 clamping detection 340 proceeds to step 354. In step 354, P6 clamping detection 340 determines whether a timeout has occurred, such as the controller 20 terminating P6 clamping detection 340 or a fault condition occurring. In step 354, if P6 clamping detection 340 determines that a timeout has occurred, P6 clamping detection 340 proceeds to step 356 and ends P6 flowchart 340A. However, in step 354, if the P6 clamping detection 340 determines that no timeout has occurred, the P6 clamping detection 340 returns to step 345 and continues to follow the P6 flowchart 340A.

[0113] Reference Figure 29 In the P6 flowchart 340A shown, in step 346, if the P6 clamping detection 340 determines that the current region is not region C, then the P6 clamping detection 340 proceeds to step 358. In step 358, the P6 clamping detection 340 determines whether the current region is region D. In step 358, if the P6 clamping detection 340 determines that the current region is region D, then the P6 clamping detection 340 proceeds to step 360, executing region D clamping detection 362. Figure 31 The process proceeds to step 364. In step 364, P6 clamping detection 340 determines whether the area identifier has changed or whether the motor 22 has been turned off. If the area identifier has not changed and the motor 22 is still on, P6 clamping detection 340 returns to step 360 and continues to run area D clamping detection 362. However, in step 364, if a change in the area identifier or the motor 22 is detected to be off, P6 clamping detection 340 proceeds to step 354. From step 354 onwards, P6 clamping detection 340 continues to follow the P6 flowchart 340A as described above.

[0114] However, in step 358, if P6 clamping detection 340 determines that the current region is not region D, then P6 clamping detection 340 proceeds to step 366. In step 366, P6 clamping detection 340 determines whether the current region is region E. In step 366, if P6 clamping detection 340 determines that the current region is region E, then P6 clamping detection 340 proceeds to step 368, executing region E clamping detection 370. Figure 30The process proceeds to step 372. In step 372, P6 clamping detection 340 determines whether the area identifier has changed or whether the motor 22 has been turned off. If the area identifier has not changed and the motor 22 is still on, P6 clamping detection 340 returns to step 368 and continues to run area E clamping detection 370. However, if a change in the area identifier or the motor 22 is turned off is detected in step 372, P6 clamping detection 340 proceeds to step 354. From step 354 onwards, P6 clamping detection 340 continues to follow the P6 flowchart 340A as described above.

[0115] When P4 region identifier 276 determines that the current region is region C, P6 clamping detection 340 selects region C clamping detection 350. As discussed above, when the rotational speed 76 increases over a period of time (e.g. Figure 4 (As shown in part 78 of the speed curve 76A), the P4 region identifier 276 selects region C. As long as the rotational speed 76 continues to rise, the P4 region identifier 276 maintains its selection of region C. However, when the rotational speed 76 no longer tends to rise, the P4 region identifier 276 will select a different region.

[0116] Reference Figure 4 The dynamics of the rotational speed 76 of velocity curve 76A in region C changing with time can be based on the equation and To estimate, for normal motion, the transfer function of region C can be approximated within a certain range by a first-order system with a time constant TC. If a clamping condition occurs when speed 76 is in region C, speed 76 will be impeded, and the feedback control of the amount of PWM power 34 supplied to motor 22 (based on a percentage of PWM duty cycle 52) will be driven more forcefully to attempt to maintain speed 76 within the target range. The increase in the amount of PWM power 34 during region C will result in a new correlation between the amount of PWM power 34 supplied to motor 22 (based on a percentage of PWM duty cycle 52) and the resulting speed 76. This new correlation will result in a new time constant TC different from the original time constant TC. new .

[0117] Figure 30 An exemplary region C flowchart 350A is shown for region C clamping detection 350 (hereinafter referred to as "region C detection"). When P6 clamping detection 340 proceeds to step 348 in P6 flowchart 340A, region C detection 350 begins at step 374 in region C flowchart 350A. Next, region C detection 350 proceeds to step 376, and for C... max G, G max G min G delta TCn H1, J1, and K1 are set to initial values, where C max It is the maximum hardware current limit, G is a calibration coefficient based on data or machine learning, G max It is the predetermined maximum value of G, G min It is the predetermined minimum value of G, G delta It is the predetermined increment value of G, TC n This refers to the nominal value of the time constant TC, where H1 is the predetermined time amount, J1 is the predetermined increase in the percentage of the PWM duty cycle 52 provided to the motor 22, and K1 is the predetermined displacement value. Next, region C detection 350 proceeds to step 378 and determines values ​​J and A. n Calculated value TC new And start counting H, where J is related to the percentage of the PWM duty cycle 52 currently supplied by controller 20 to motor 22, A n The instantaneous current 58 TC drawn from motor 22. new The new time constant is based on the current rate of change of rotational speed 76 over time and the amount of PWM power 34 supplied by controller 20 to motor 22 (based on the percentage of PWM duty cycle 52), where H is the time quantity. After step 378, region C detection 350 proceeds to step 380 and determines the new time constant TC. new Is it greater than the nominal value TC of the calibration coefficient G multiplied by the time constant? n (Right now, ).

[0118] In step 380, if TC new Less than or equal to Then, the detection in region C proceeds to step 382 and determines the instantaneous current A. n Is it less than the maximum hardware current? In step 382, ​​if the instantaneous current A n Less than the maximum hardware current C max If the region C detection 350 proceeds to step 384, it determines whether there is a change in the regions (C, D, E) identified by the P4 region identifier 276 or whether the motor 22 is off. In step 384, if the region C detection 350 determines that there is no change in the identified regions (C, D, E) and the motor 22 is still receiving PWM power 34, then the region C detection 350 returns to step 378 and continues following the region C flowchart 350A. However, if in step 384 the region C detection 350 determines that there is a change in the identified regions (C, D, E) or the motor 22 is off, then the region C detection 350 proceeds to step 386 and ends the region C flowchart 350A.

[0119] However, in step 380, if region C is detected by 350, TC is determined. new Greater than Then, region C detection proceeds to step 388 and determines whether the current value of H is greater than the value H1 (i.e., In step 388, if region C detection 350 determines that the current value of H is greater than the value H1, then region C detection 350 determines that preliminary clamping has been detected (step 390), and in step 392, the controller 20 is instructed to increase the current percentage of the PWM duty cycle 52 to the motor 22 by an amount J1 (i.e., In response to an increase in the percentage of the PWM duty cycle 52 to motor 22, the displacement K of component 26 is measured, and the process proceeds to step 394. In step 394, region C detection 350 determines whether the displacement K measured within a predetermined time period is less than the displacement value K1 (i.e., In step 394, if region C detection 350 determines that the measured displacement K is less than the displacement value K1, then region C detection 350 determines that a mature pinch has been detected (step 396), terminates the PWM power 34 of motor 22 (step 398), and ends region C flowchart 350A (step 386).

[0120] However, in step 388, if region C detection 350 determines that H is less than or equal to H1, then region C detection 350 proceeds to step 382 and continues to follow the region C flowchart 350A as described above. Additionally, in step 394, if region C detection 350 determines that the displacement K is equal to or greater than the displacement value K1, then region C detection 350 proceeds to step 400. In step 400, region C detection 350 resets the initial clamping and sets... Proceed to step 382, ​​and continue following the region C flowchart 350A as described above. In step 382, ​​if region C detection 350 determines the instantaneous current A... n Greater than or equal to the maximum hardware current C max Then, region C detection 350 proceeds to step 402, setting... Proceed to step 398 and continue following the flow chart 350A of region C as described above.

[0121] Reference Figure 4 , Figure 29 and Figure 30 The clamping detection in region E 370 is similar to the clamping detection in region C 350 described above. For example... Figure 4 As shown, the rotational speed 76 decreases over time in region E. In contrast, the rotational speed 76 increases over time in region C. Figure 30The flowchart 350A for region C can be used to detect the clamping condition in regions E and C. However, region E detection 370 may optionally use G, G', which are different from the corresponding initial values ​​used in region C detection 350. max G min G delta K1, H1, J1 and TC n The initial value.

[0122] Reference Figure 29 When P4 region identifier 276 selects region D as the current region, P6 clamping detection 340 selects region D clamping detection 362. As discussed above, when the rotational speed 76 stabilizes over time (e.g. Figure 4 (As shown in the speed curve 76A portion 80), the P4 region identifier 276 selects region D. As long as the rotational speed 76 is within the target range 112, the P4 region identifier 276 maintains its selection of region D. However, when the rotational speed 76 is no longer within the target range 112, the P4 region identifier 276 will select a different region.

[0123] Reference Figure 22 The region D clamping detection 362 (hereinafter referred to as "region D detection") evaluates the power difference 404 between electrical power 270 and mechanical power 272 over a time period. As discussed above, at time t n Instantaneous power EP at the point n ( Figure 22 ) Calculated from P3 power 266 based on time t n instantaneous voltage V at point n ( Figure 20 ) and instantaneous current A n ( Figure 21 This is determined by ( ). Additionally, time t n instantaneous mechanical power MP n ( Figure 22 ) Calculated from P3 power 266 based on time t n Instantaneous mechanical force MF at the location n ( Figure 23 ) and instantaneous time difference DT n ( Figure 24 The value DT is determined by ) n It is the HE Delta_T between 38 consecutive HE pulses, and is related to the rotational speed of the output shaft 28, which is 76 ( Figure 4 It is inversely proportional to t. Under normal operating conditions, time t n The power difference of 404 at that point was calculated as the instantaneous electric power EP. n With instantaneous mechanical power MP n The difference between them (i.e., ,in It is time tn The power difference 404 between electrical power 270 and mechanical power 272 is related to the amount of power required to overcome friction and normal loads on the seat assembly 10 when the component 26 is repositioned between the first position 42 and the second position 46.

[0124] Reference Figures 31 to 33 Region D detection 362 is configured to detect different clamping conditions. One clamping condition is soft clamping 406 or compressible clamping, in which part 26 or another part of seat assembly 10 impacts a compressible object when part 26 is repositioned. When soft clamping 406 occurs, controller 20 will drive motor 22 at a higher power state in response to a decrease in rotational speed 76. However, even after controller 20 increases the amount of PWM power 34 supplied to motor 22, rotational speed 76 will remain slow or decrease.

[0125] More specifically, Figure 31 The time-varying electrical power 270 and mechanical power 272, determined by power calculation 266 using P3, are shown. Due to the instantaneous electrical power EP... a EP b The amplitude at time t a With t b The increase between, and the instantaneous mechanical power MP a MP b The amplitude within the same time range t a t b The internal decreases, therefore the soft clamp 406 at time t a It started happening nearby and at time t b It continues to occur at that point. Additionally, at time t... b Instantaneous power EP at the point b With mechanical power MP b The power difference between them is 404', which is greater than the power difference at time t. n The power difference at that location is 404. Figure 32 and Figure 33 It shows that in such Figure 31 The electrical power 270 and rotational speed 76 vary over time within the same time range, as shown. The instantaneous value EP of the electrical power is also shown in response to the occurrence of soft clamping 406. a EP b Within the time range t a t b The internal value gradually increases, and the instantaneous value S at 76 rotation speed. a S b Within the same time range t a t b The internal volume gradually decreases.

[0126] exist Figure 31In one embodiment shown, region D detection 362 detects soft clamping 406 by determining the amount of energy E consumed in attempting to overcome the clamping condition. The amount of energy E is calculated by measuring the instantaneous electrical power EP. a With instantaneous mechanical power MP a The power difference between them is 404 and time t a With time t b The power difference of 404 is determined by integrating the quantity. The energy E is determined by... Figure 31 Region E1 is represented in the diagram. Region D detector 362 compares the amount of energy E with a predetermined energy threshold TH (not shown). If the amount of energy E (region E1) is greater than the energy threshold TH, preliminary clamping is detected. If preliminary clamping is detected, controller 20 then... b The amount of PWM power 34 supplied to motor 22 will be increased by a predetermined amount, and a predetermined amount of time (such as at time t) will be monitored. b The amount of energy E consumed between tc and tc, which corresponds to Figure 31 The region is E2. If controller 20 is at time t b After increasing the amount of PWM power 34 supplied to motor 22, EP b MP b With EP c MP c The amount of energy E between them increases (i.e., Figure 31 If region E2 > region E1, then a complete clamping condition is detected. However, if the controller 20 at time t b After increasing the power, EP b MP b With EP c MP c The amount of energy E between them decreases (i.e., Figure 31 If region E2 < region E1, then complete clamping is not detected. Region D detects 362 to clear the initial clamping and continues to monitor the amount of energy E for the occurrence of a new soft clamping condition.

[0127] Reference Figures 31 to 33 The full clamping status is also indicated by the following: after initial clamping is detected and after the controller 20 has increased the amount of PWM power 34 supplied to the motor 22, the electrical power 270 supplied to the motor 22 increases and the speed 76 decreases. Figure 32 Electric power EP a EP b EP c and Figure 33 The speed S in a S b S c Corresponding to Figure 31 Electric power EP a EP b EP c and mechanical power MP a MP b MP c And respectively at time t a t b t c Occurred at location D. Detection 362 occurred at time t. b The initial clamping status is determined at point t and at time t c The complete clamping status is confirmed at this point. The complete clamping status is also determined by... Figure 32 Part 410 and Figure 33 Part 412 in the document is confirmed. More specifically, due to... Figure 32 Part 410 shows the amount of electrical power 270 increasing over time, and Figure 33 Part 412 shows that the rotational speed 76 does not increase substantially over time, thus confirming full clamping. In contrast, region D detection 362 is based on... Figure 32 Part 414 and Figure 33 Part 416 clears the previous full clamping as the electrical power 270 decreases over time (part 414) and the rotational speed 76 increases over time (part 416). The combination of the increase in rotational speed 76 over time and the decrease in electrical power 270 indicates that the seat assembly 10 has recovered from the soft clamping and is operating normally.

[0128] Zone D detection 362 can optionally be configured to adjust the value of the energy threshold TH based on whether zone D detection 362 identifies a full clamping or whether zone D detection 362 resets the initial clamping. For example, if zone D detection 362 identifies an initial clamping that is not confirmed as a full clamping, zone D detection 362 can increase the energy threshold TH. Furthermore, if zone D detection 362 does not identify an initial clamping, but the amount of current 58 drawn by motor 22 exceeds the maximum hardware current C... max Therefore, region D detection 362 can reduce the energy threshold TH. Additionally, region D detection 362 can be configured similarly to region C detection 350 for adjusting the calibration coefficient G. Figure 30 The method is to adjust the value of the energy threshold TH.

[0129] Region D detection 362 is configured to detect another clamping condition described as a hard collision 418, such as Figures 34 to 36 As shown. Figure 34 The electrical power 270 and mechanical power 272 as a function of time are shown. Figure 35 and Figure 36 The electrical power of 270 and the rotational speed of 76 are shown as a function of time. (Refer to...) Figures 34 to 36 Hard collision 418 initially at time t f This occurs nearby, at which point component 26 or another part of seat assembly 10 impacts a hard object (not shown) while component 26 is being repositioned. Furthermore, the hard impact 420 occurs at the time tg corresponding to the stall of motor 22 and the drop in speed 76 to zero. If the amount of electrical power 270 supplied to motor 22 is insufficient to overcome the load on motor 22, motor 22 stalls.

[0130] When a hard collision 418 occurs, the current 58 and power 270 supplied to the motor 22 will rapidly increase, and the rotational speed 76 will rapidly decrease over time. Furthermore, the hard collision 418 may cause the component 26 to reposition itself away from the hard object in the opposite direction of travel in response to encountering it. During the period when the controller 20 supplies power 270 to the motor 22, the forward / reverse movement of the component 26 may cause spikes 422, 424 in the amount of power 270 supplied to the motor 22 due to repeated hard collisions 420 by the component 26. (Refer to...) Figure 34 The hard collision 418 causes a rapid change in the amplitude of the electrical power 270, accompanied by upward and downward spikes 422 and 424. In contrast, the hard collision 418 causes the amplitude of the mechanical power 272 to decrease rapidly in response to the rapid decrease in rotational speed 76. The hard collision 418 causes the power difference 404' between the electrical power 270 and the mechanical power 272 to increase compared to the power difference 404 during normal operation. The amplitude of the power difference 404' is greater than the amplitude of the power difference 404 during normal operation because additional power is being consumed when the controller 20 attempts to overcome the hard collision 418.

[0131] Early detection of a hard impact 418 may be necessary to avoid a hard impact 420. Region D detection 362 includes a detection index that places more weight on the rate of power increase than on the amount of energy E consumed to overcome the clamping condition. The detection index may include one or more of the peak value 426 of the electrical power 270, the slope of the changing electrical power 270, and the integral of the absolute value of the change in energy E over time to detect a hard impact 418. Additionally, Region D detection 362 may include an energy threshold TH to determine the occurrence of a hard impact 418, similar to the method described above using the detection of soft clamping 406. Typically, Region D detection 362 immediately determines full clamping upon detection of a hard impact 418. In contrast, Region D detection 362 identifies initial clamping upon detection of soft clamping 406, subsequently confirming full clamping.

[0132] However, if the maximum hardware current C is exceeded before the occurrence of hard collision 418 is detected in region D (detection 362),... maxThen, region D detection 362 can decrease the energy threshold TH by a predetermined amount within a specified fixed range. Adjusting the energy threshold TH based on the accuracy of detecting hard collisions 418 optimizes region D detection 362 without requiring manual calibration of the detection process.

[0133] Figures 37 to 39 Additional scenarios in region D and their effects on electrical power 270 and mechanical power 272 are shown. Figure 37 The first scenario 428 is shown, in which both electrical power 270 and mechanical power 272 gradually increase over time. For example, at time t... b Power output EP b With mechanical power MP b The power difference between them is 404', which is greater than the power difference at time t. n Power output EP n With mechanical power MP n The power difference 404 between the first power difference 404 and the second power difference 404' is insufficient to trigger region D detection 362. If the controller 20 includes speed control, then Figure 37 The first scene 428 is impossible.

[0134] In comparison, Figure 38 The second scenario 430 is shown, in which electrical power 270 increases over time, while mechanical power 272 remains stable or decreases slightly. More specifically, at time t... b The electrical power EP at the location b With mechanical power MP b The power difference between them is 404', which is greater than the power difference at time t. n The electrical power EP at the location n With mechanical power MP n The power difference 404 between the first power difference 404 and the second power difference 404' is insufficient to trigger region D detection 362. If the controller 20 includes speed control, a second scenario 430 may occur. However, the energy threshold TH can be based on the power differences 404, 404', and time t. n With t b The difference in rotational speed (76) and time (t) between them n With t b The energy threshold TH is determined as a function of the difference in PWM power between 34. This is based on the time period t. n t b The changes in power difference 404, 404', speed 76, and / or PWM power 34 within the region will provide a more robust threshold TH and increase the reliability of the detection of soft clamping 406 and hard collision 418 in area D detection 362.

[0135] Figure 39The third scenario 432 is shown, in which the electrical power 270 is in time period t. n t b The internal power increases rapidly while the mechanical power 272 decreases rapidly. In the third scenario 432, the increase in power difference 404, 404' over time is compared to... Figure 37 and Figure 38 The speed is faster, as shown. Region D detection 362 may detect both soft clamping 406 and hard collision 418.

[0136] Figure 40 The fourth scenario 434 is shown, where the electrical power 270 is at time t. n EP at the location n With time t b EP at the location b The power increases rapidly between t and t, but the electrical power of 270 increases rapidly between t and t. b EP at the location b With time t c EP at the location c The values ​​tend to stabilize between these values. Furthermore, the mechanical power 272 at time t... n MP at the location n With time t b MP at the location b The power gradually decreases between t, and then the mechanical power of 272 decreases over time t. b MP at the location b With time t c MP at the location c It gradually increases or remains at a low level. This results in a time t b The power difference at point 404' is greater than that at t n The power difference at that point is 404, but this difference may not be sufficient to trigger a response at time t. b A clamping condition was detected at that point. However, at time t... c The power difference at point 404'' is also greater than that at time t. n The power difference at point 404. Region D detector 362 will detect the clamping condition because the increase in power difference 404', 404'' is related to the time t. n The power difference at point 404 has been maintained for an extended period of time t. b t c Therefore, the fourth scenario 434 may cause a delay in the region D detection 362's identification of soft clamping 306 or hard collision 418. However, the region D detection 362 will still identify the clamping condition.

[0137] Figure 41 The fifth scenario 436 is shown, in which the electrical power 270 is at time t. n EP at the location n With time t b EP at the location bIt increases rapidly between, and at time t b EP at the location b With time t c EP at the location c It continues to increase between. Furthermore, the mechanical power 272 increases over time t. n MP at the location n With time t b MP at the location b The power gradually decreases between t, and then the mechanical power of 272 decreases over time t. b MP at the location b With time t c MP at the location c The level remains low. Region D detection 362 may detect the clamping condition earlier in scenario 436 than in scenario 434, because the electrical power 270 at time t... b With t c The detection index can be based on the amount of energy E consumed within a selected time range, obtained by integrating the power differences 404, 404', and 404'' over the time range. Furthermore, the detection index can be based on a fatigue coefficient affected by speed increases and / or a coefficient based on the rate of change of the power difference 404 over time. For example, even if the electrical power 270 is higher than the normal range, the detection index can decrease in response to an increase in rotational speed 76. Moreover, if the power differences 404, 404', and 404'' decrease over time, the detection index can decrease or reset at a faster rate. (See reference...) Figure 41 When calculating the detection index, at time t b EP at the location b With time t c EP at the location c The portion of the electrical power between 270 and time t is greater than that between 270 and time t. n EP at the location n With time t b EP at the location b The electrical power of 270 is even more critical.

[0138] exist Figure 43 HE flowchart 438 and Figure 44 An exemplary implementation of the P6 clamping detection 340 is shown in power flow diagram 440. The P6 clamping detection 340 is based on a detection index, which is a function of the various factors mentioned above (e.g., power differences 404, 404', 404'', energy difference E, increase in electrical power 270, decrease rate of mechanical power 272, etc., as non-limiting examples). An efficient method includes using full integral detection of power. The detection index is weighted using different types of functions based on the currently identified regions C, D, E in the final calculation.

[0139] Reference Figure 43 When a new measurement value is received, HE flowchart 438 begins at step 442 and proceeds to step 444. Next, in step 444, controller 20 determines whether the received new measurement value is at least X% smaller than the old measurement value in the long-term buffer, where X% is a predetermined value. In step 444, if the new measurement value is not less than the old measurement value by at least X%, controller 20 proceeds to step 446, decrements the HE counter, and proceeds to the end of HE flowchart 438 in step 448. However, in step 444, if controller 20 determines that the new measurement value is at least X% smaller than the old measurement value, controller 20 proceeds to step 450, increments the HE counter, and proceeds to step 452. In step 452, controller 20 determines whether the HE counter is greater than a first threshold TH and whether the power counter is greater than zero. In step 452, if the controller 20 determines that the HE counter is greater than the first threshold TH and the power counter is greater than zero, then in step 454, the controller 20 sends a signal to notify the clamping HE status, and in step 448 proceeds to the end of the HE flowchart 438. However, in step 452, if the controller 20 determines that the HE counter is not greater than the first threshold TH and / or the power counter is not greater than zero, then in step 448, the controller 20 directly proceeds to the end of the HE flowchart 438.

[0140] Reference Figure 44 When a new measurement value is received, power flow chart 440 begins at step 456 and proceeds to step 458. Next, in step 458, controller 20 determines whether the received new measurement value is at least X% greater than the old measurement value in the long-term buffer, where X% is a predetermined value. In step 458, if the new measurement value is not greater than the old measurement value by at least X%, controller 20 proceeds to step 460, decrements the power counter, and proceeds to the end of power flow chart 440 in step 462. However, in step 458, if controller 20 determines that the new measurement value is at least X% greater than the old measurement value, controller 20 proceeds to step 464, increments the power counter, and proceeds to step 466. In step 466, controller 20 determines whether the power counter is greater than a second threshold TH' and whether the HE counter is greater than zero. In step 466, if the controller 20 determines that the power counter is greater than the second threshold TH' and the HE counter is greater than zero, then in step 468, the controller 20 signals the clamping power status, and in step 462, it proceeds directly to the end of the power flow chart 440. However, in step 466, if the controller 20 determines that the power counter is not greater than the second threshold TH' and / or the HE counter is not greater than zero, then in step 462, the controller 20 directly proceeds directly to the end of the power flow chart 440.

[0141] Figure 45 The detection flowchart 470 illustrates a second exemplary implementation of the P6 clamping detection 340. (Refer to...) Figure 45 The detection flowchart 470 begins at step 472 and proceeds to step 474. In step 474, controller 20 determines whether motor 22 is moving. If controller 20 determines that motor 22 is not moving in step 474, controller 20 proceeds to the end of detection flowchart 470 in step 476. However, if controller 20 determines that motor 22 is moving in step 474, controller 20 proceeds to step 478 and determines whether the current long-term counter is less than or equal to the current long-term count. In step 478, if controller 20 determines that the current long-term counter is less than or equal to the current long-term count, controller 20 proceeds to step 480. In step 480, controller 20 determines whether the current short-term counter is less than or equal to the current short-term count. If controller 20 determines that the current short-term counter is less than or equal to the current short-term count, controller 20 proceeds to step 482, where the current buffer is filled, and proceeds to step 484. In step 484, controller 20 detects clamping behavior by both power and HE, or only when the power is greater than the boundary threshold TH. b The clamping behavior is detected by power detection.

[0142] In one implementation, the boundary threshold TH b It is a predetermined value. In another embodiment, the boundary threshold TH b yes Figure 46 The detection boundary is shown in the figure. An example boundary threshold TH. b Defined as a function of the calculated power and HE Delta T, as shown in Equation 1 below (as one possible option). More specifically, the boundary threshold TH is defined as the calculated power varies from 0 to the second threshold TH' and HE Delta T varies from 0 to TH. b It is calculated as ((calculated power / TH') 2 +(HE Delta T / TH) 2 The square root of ) is 1. The function f(pwr,HE) can be used as an exponent to detect and indicate the clamping state.

[0143]

[0144] Figure 46A graph is shown with HE Delta_T on the y-axis and the calculated power on the x-axis. Region A includes part A1 of the graph where HE Delta_T is equal to or greater than a first threshold TH. Region A also includes part A2 of the graph where the calculated power is equal to or greater than a second threshold TH'. Region A represents a first clamping interval where the motor 22 is encountering a clamping behavior. Additionally, the value V1 lies within Region A because the value V1 has a calculated power and / or HE delta T HEC3 TH.

[0145] Region C is defined as the portion bounded by the curve TH b i.e., f(pwr, HE) < 1, the x-axis is between 0 and TH', and the y-axis is between 0 and TH. Region C represents the normal operating interval for the motor 22 when the motor 22 is not experiencing any clamping behavior. For example, the value V2 lies within Region C because the value V2 has a calculated power of PC1 < TH', HE Delta_T HEC1 < TH, and the value V2 lies below the curve TH b below.

[0146] In contrast, Region B is bounded by the curve TH b and Region A. Region B represents a second clamping interval where the motor 22 is encountering a clamping behavior. For example, the value V3 lies within Region B because the value V3 has a calculated power PC2 < TH', HE Delta_THEC2 < TH, and the position (PC2, HEC2) is outside Region C (f(pwr, HE) > 1 at V3).

[0147] Referring Figure 45 to, after the controller 20 completes step 484, the controller 20 proceeds to the end of the detection flowchart 470 in step 476. However, in step 480, if the controller 20 determines that the current short-term counter is greater than the current short count, the controller 20 proceeds to step 486, where the power buffer is filled, and then proceeds to step 484. The controller 20 continues to follow the detection flowchart 470 as described above starting from step 484.

[0148] However, in step 478, if the controller 20 determines that the current long-term counter is greater than the current long-term count, the controller 20 proceeds to step 488. In step 488, the controller 20 detects clamping behavior via power and proceeds to step 490. In step 490, the controller 20 determines whether the HE long-term counter is less than or equal to the HE long-term count. If the controller 20 determines that the HE long-term counter is greater than the HE long-term count, the controller 20 proceeds to step 492. In step 492, the controller 20 detects clamping behavior via HE and proceeds to step 484, and from step 484 onwards continues to follow the detection flowchart 470 as described above.

[0149] like Figure 45 As shown, in step 490, if controller 20 determines that the HE long-term counter is less than or equal to the HE long-term count, controller 20 proceeds to step 494. In step 494, controller 20 determines whether the HE short-term counter is less than or equal to the HE short-term count. If controller 20 determines that the HE short-term counter is less than or equal to the HE short-term count, controller 20 proceeds to step 496, where the position buffer is filled, and proceeds to step 484. From step 484, controller 20 continues to follow the detection flowchart 470 as described above. However, if in step 494 controller 20 determines that the HE short-term counter is greater than the HE short-term count, controller 20 proceeds to step 498 and fills the travel buffer. After controller 20 fills the travel buffer in step 498, controller 20 then proceeds to step 484 and continues to follow the detection flowchart 470 as described above.

[0150] like Figure 10 As shown, after controller 20 initiates P6 clamping detection 340 (step 342), controller 20 initiates P7 threshold update 500 in step 502. P7 threshold update 500 continues until terminated by controller 20. (See reference...) Figure 42The P7 threshold update 500 adjusts the value of the threshold TH used in various calculations by the P5 event analysis 280 and the P6 clamping detection 340. In some implementations, a fixed threshold TH is included in a specific calculation. In other implementations, several different values ​​are used to calibrate the threshold TH in response to various conditions. The P7 threshold update 500 includes a self-adjustable threshold TH within a certain range. More specifically, the maximum-minimum range (Pwr_max, Pwr_min) of the power difference 404, 404', 404'' and the maximum-minimum range of the energy difference E are defined based on the stall current and nominal operation. Within the boundaries of the maximum-minimum range (Pwr_max, Pwr_min) of the power difference 404, 404', 404'' and the optional maximum-minimum range of the energy difference E, if the detection of the clamping condition is missed but protected by hardware current C max If a clamping condition is detected, the threshold TH is adjusted to be lower. The P6 clamping detection 340 may miss clamping conditions due to variations caused by aging or temperature effects. Furthermore, if a detected initial clamping condition is cleared by an additional PWM duty cycle of 52, the threshold TH is adjusted to be higher.

[0151] exist Figure 42 In the illustrated implementation, the value of the threshold TH is adjusted between an upper threshold 504 (for the power differences 404, 404', 404'') and a lower threshold 506 (for the power differences 404, 404''). The power range 508 represents the nominal power during normal operating conditions. Stall power / current is indicated by element 510. Therefore, the adjustable threshold TH range is smaller than the stall power / current 510 but larger than the nominal power range during normal operating conditions. The P7 threshold update 500 evaluates and adjusts the value of the threshold TH at the end of each detected clamping event. When ignition is off, the adjusted threshold TH is saved to NVRAM for future use.

[0152] like Figure 10As shown in the sequence flowchart 142A, after controller 20 initiates P7 threshold update 500 in step 502, controller 20 proceeds to step 512 and determines whether the vehicle ignition is off. In step 512, if the vehicle ignition is on, controller 20 returns to step 146 and continues the process in sequence flowchart 142A. However, if controller 20 determines in step 512 that the vehicle ignition is off, controller 20 proceeds to step 514 and initiates P8 NVRAM process 516. P8 NVRAM process 516 handles functions similar to P1 NVRAM process 147, including the data readout process, data recording, ignition cycle counting, and updating health status information as described above. Furthermore, P8 NVRAM process 516 terminates P1 NVRAM process 147, P2 Hall effect process 260, P3 power calculation 266, P4 area identifier 276, P5 event analysis 280, P6 clamping detection 340, and P7 threshold update 500, and stores the current values ​​of various adjustable parameters such as threshold TH, maximum limit, and minimum limit. Additionally, P8 NVRAM process 516 stores values ​​such as the number of ignition cycles and the number of times the motor 22 is energized. After P8 NVRAM process 516 terminates processes P1 to P7 in step 514 and stores the values ​​in NVRAM, controller 20 proceeds to step 518, shuts off the power to controller 20, and proceeds to step 520, ending the sequence flowchart 142A.

[0153] As discussed above, the seat assembly 10 of the present invention includes an anti-pinch detection system 12 that focuses on the amount of energy used by the electric motor 22 to move the components 26 of the seat assembly 10. The anti-pinch detection system 12 can detect abnormal obstruction of movement and can detect obstruction of movement of the electric motor 22. Furthermore, the anti-pinch detection system 12 is capable of drawing the maximum hardware current C from the electric motor 22. max Hard collisions and soft clamping conditions were detected previously.

[0154] More specifically, the anti-pinch detection system 12 evaluates power conversion and dissipation rates to detect clamping conditions. Furthermore, the anti-pinch detection system 12 includes robust threshold generation with balanced and effective detection performance. The anti-pinch detection system 12 also includes event-based data analysis, making clamping condition detection robust and reliable. Event-based data analysis enables efficient detection of clamping conditions and reduces calibration work based on various voltage ranges or specific conditions. In addition to detecting clamping conditions, the anti-pinch detection system 12 is configured to identify potential changes in the performance of the motor 22 due to aging or overuse scenarios. Power and energy dissipation-based approaches support a unified solution for detecting hard impacts and soft clamping conditions. Furthermore, detection statistics can be used to determine short-term and long-term compensation based on changing conditions. Additionally, the anti-pinch detection system 12 includes aggregated statistical data collected over time, which is used for health status assessment to determine the health status of the motor 22. Moreover, the aggregated statistical data provides additional insights for further service.

[0155] The present invention has been described in an illustrative manner, and it should be understood that the terminology used is intended to describe the nature of the words rather than to limit their nature. In view of the above teachings, many modifications and variations of the invention are possible. Therefore, it should be understood that the invention can be practiced in ways other than those specifically described within the scope of the appended claims.

Claims

1. A method for detecting the clamping condition of a seat assembly used in a motor vehicle, wherein, The seat assembly includes a controller operatively coupled to a motor having an output shaft and a Hall effect sensor configured to output a Hall effect pulse to the controller when the motor rotates the output shaft. The method includes the following steps: Provides calibration coefficient G, predetermined time quantity H1, and predetermined time constant TC. n ; Acquire the first plurality of Hall effect pulses received from the Hall effect sensor during the first time period; The first rotational speed of the output shaft during the first time period is determined based on the first plurality of Hall effect pulses; Determine a new time constant TC related to the amount of change of the first rotational speed during the first time period. new ; Determine the new time constant TC new Is it greater than the calibration coefficient G multiplied by the time constant TC? n At least the time amount H1; and If the new time constant TC new Greater than the calibration coefficient G multiplied by the time constant TC n If at least the specified time H1 is reached, it is determined that a preliminary clamping condition has occurred.

2. The method according to claim 1, further comprising: Provide a predetermined quantity J1 and a predetermined displacement quantity K1; After the initial clamping condition has occurred, the amount of the PWM duty cycle of the motor is increased by the predetermined amount J1 and the second time period is started; Displacement K is acquired during the second time period, wherein the displacement K is based on a second plurality of Hall effect pulses received during the second time period; as well as If the displacement K at the end of the second time period is less than the predetermined displacement K1, then it is determined that a complete clamping condition has occurred.

3. The method according to claim 2, further comprising: If the displacement K is greater than or equal to the predetermined displacement K1, then the initial clamping state is reset.

4. The method according to claim 3, further comprising: Provide G delta The predetermined value and G max The predetermined value; as well as If the displacement K is greater than or equal to the predetermined displacement K1, then the calibration coefficient G is set to be equal to G+G. delta With G max The minimum value in.

5. The method according to claim 1, further comprising: Provides maximum hardware current C max The predetermined value; Provide G delta The predetermined value and G min The predetermined value; If the new time constant TC new Less than or equal to the calibration coefficient G multiplied by the time constant TC n If at least the specified time H1 is reached, it is determined that the initial clamping condition has not occurred; Obtain the first current drawn by the motor during the first time period; Determine whether the amount of the first current drawn by the motor during the first time period is equal to or greater than the maximum hardware current C. max ; as well as If the first current drawn by the motor is equal to or greater than the maximum hardware current C max If the initial clamping condition does not occur, then the calibration coefficient G is set to be equal to GG. delta With G min The maximum value in.

6. The method according to claim 1, wherein: The calibration coefficient G is adjusted over time in response to resetting the initial clamping condition.

7. The method according to claim 1, further comprising: Provides maximum hardware current C max The predetermined value; Obtain the first current drawn by the motor during the first time period; as well as If the initial clamping condition does not occur, then in response to the first current exceeding the maximum hardware current C max To adjust the calibration coefficient G.

8. A method for detecting the clamping condition of a seat assembly used in a motor vehicle, wherein, The seat assembly includes a controller operatively coupled to a motor having an output shaft and a Hall effect sensor configured to output a Hall effect pulse to the controller when the motor rotates the output shaft. The method includes the following steps: Provide a predetermined energy threshold TH; Acquire the first voltage and first PWM power supplied to the motor during the first time period, the first current drawn by the motor, and the first plurality of Hall effect pulses received from the Hall effect sensor; The first electrical power supplied to the motor is determined based on the first voltage and the first current during the first time period; The first mechanical power supplied by the motor is determined based on the first PWM power supplied to the motor during the first time period and the first plurality of Hall effect pulses received from the Hall effect sensor; Determine a first power difference between the first electrical power and the first mechanical power during the first time period; The amount of the first energy, E1, is determined by integrating the first power difference over the first time period; and When the amount of the first energy E1 is greater than the predetermined energy threshold TH, it is determined that a preliminary clamping condition has occurred.

9. The method according to claim 8, further comprising: Provide the target scope; Before starting the first time period, determine the rotational speed of the output shaft; as well as If the rotational speed is within the target range, then the first time period is initiated.

10. The method according to claim 9, wherein, The rotational speed is based on the count of Hall effect pulses received within a predetermined time interval.

11. The method according to claim 9, wherein, The rotational speed is based on the amount of time between consecutive leading edges of the Hall effect pulse.

12. The method according to claim 8, further comprising: Acquire the second voltage and second PWM power supplied to the motor during a second time period following the first time period, the second current drawn by the motor, and the second plurality of Hall effect pulses received from the Hall effect sensor; The second electrical power supplied to the motor is determined based on the second voltage and the second current during the second time period; The second mechanical power supplied by the motor is determined based on the second PWM power supplied to the motor during the second time period and the second plurality of Hall effect pulses received from the Hall effect sensor; Determine a second power difference between the second electrical power and the second mechanical power during the second time period; as well as The amount of the second energy, E2, is determined by integrating the second power difference over the second time period.

13. The method of claim 12, further comprising: When the amount of the second energy E2 is greater than the predetermined energy threshold TH, it is determined that a complete clamping condition has occurred.

14. The method of claim 12, further comprising: When the amount of the second energy E2 is greater than the amount of the first energy E1, it is determined that a complete clamping state has occurred.

15. The method of claim 12, further comprising: If the amount of the second energy E2 is less than or equal to the predetermined energy threshold TH, then the initial clamping condition is reset.

16. The method of claim 13, further comprising: Obtain the third PWM power amount supplied to the motor during a third time period after the first time period and after the second time period; as well as If the third PWM power is less than the second PWM power, then the full clamping state is reset.

17. The method of claim 13, further comprising: The second rotational speed is determined based on the second plurality of Hall effect pulses received during the second time period; Acquire a third plurality of Hall effect pulses received from the Hall effect sensor during a third time period following the first time period and following the second time period; The third rotational speed is determined based on the third plurality of Hall effect pulses; as well as If the third rotational speed is greater than the second rotational speed, then the fully clamped state is reset.

18. A method for detecting the clamping condition of a seat assembly used in a motor vehicle, wherein, The seat assembly includes a controller operatively coupled to a motor having an output shaft and a Hall effect sensor configured to output a Hall effect pulse to the controller when the motor rotates the output shaft. The method includes the following steps: Provide a predetermined energy threshold TH; Acquire the first voltage and first PWM power supplied to the motor during the first time period, the first current drawn by the motor, and the first plurality of Hall effect pulses received from the Hall effect sensor; The first electrical power supplied to the motor is determined based on the first voltage and the first current during the first time period; The first mechanical power supplied by the motor is determined based on the first PWM power supplied to the motor during the first time period and the first plurality of Hall effect pulses received from the Hall effect sensor; Determine a first power difference between the first electrical power and the first mechanical power during the first time period; Acquire the second voltage and second PWM power supplied to the motor during the second time period, the second current drawn by the motor, and the second plurality of Hall effect pulses received from the Hall effect sensor; The second electrical power supplied to the motor is determined based on the second voltage and the second current during the second time period; The second mechanical power supplied by the motor is determined based on the second PWM power supplied to the motor during the second time period and the second plurality of Hall effect pulses received from the Hall effect sensor; Determine the second power difference between the second electrical power and the second mechanical power during the second time period; and When the second power difference is greater than the first power difference and greater than the predetermined energy threshold TH, it is determined that a clamping situation has occurred.

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