Trapping prevention guard and method for controlling a motor-driven adjusting device

• US 7,786,689 B2
• Filed: 02/15/2007
• Issued: 08/31/2010
• Est. Priority Date: 02/17/2006
• Status: Active Grant

• Current Assignee: Brose Fahrzeugteile GmbH & Co. KG
• Original Assignee: Brose Fahrzeugteile GmbH & Co. KG
• Inventors: Rösch, Thomas
• Primary Examiner(s): Duda; Rina I
• Application Number:
  US12/279,706
• Publication Number:
  US 20090039814A1
• Time in Patent Office: 1,293 Days
• Field of Search: 318/432, 318/434, 318/538, 318/445, 318/466, 701/36, 701/49
• US Class Current: 318/432
• CPC Class Codes: H02H 3/006 Calibration or setting of parameters
• CPC Class Codes: H02H 7/0851 for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal

Abstract

In order to reliably detect a jamming situation, in particular in a seat adjusting means, provision is made for a total loading exerted by the drive during a start phase to be determined and for this to be fixed as the basic loading. The existence or non-existence of a jamming situation is finally determined during a monitoring phase by comparing the basic loading and the total loading that varies during operation of the adjusting apparatus.

Claims

1. A trapping prevention guard for an adjusting device, the trapping prevention guard comprising

a motorized drive and

a control unit that is configured to derive an initial total load exerted by the motorized drive from at least one detected characteristic variable of the motorized drive in order to monitor for a trapping instance,

wherein the control unit is configured to derive the initial total load during a start phase at the beginning of an actuation operation of the adjusting device and to store the initial total load as the nominal load of the adjusting device

wherein the control unit is configured to determine whether trapping has occurred during a monitoring phase from a comparison between the nominal load and a total load which varies during the actuation operation of the adjusting device and

wherein the control unit employs a first mathematical model in order to determine the total load, and changes over to a second mathematical model that takes into account the trapping instance only if there is a significant deviation between the total load and the nominal load or if there is a significant deviation in the detected characteristic variable for assessing whether trapping has occurred.

2. The trapping prevention guard according to claim 1, wherein only the second model comprises a spring model which takes into account the trapping instance.

3. The trapping prevention guard according to claim 1, wherein, when a changeover is made to the second model, at least some of the variables previously determined with the first model are used as input variables for the second model.

4. The trapping prevention guard according to claim 1, wherein the significant deviation occurs as the result of

exceeding a limit value for the difference between the total load and nominal lead or

exceeding a limit value for a derivative of the difference, or both.

5. The trapping prevention guard according to claim 1, wherein the nominal load is stored when the significant deviation occurs, and the further profile of the total load, represented as the difference between the current total load and the previously stored nominal load, is monitored for the presence of a trapping instance.

6. A trapping prevention guard for an adjusting device, the trapping prevention guard comprising

a motorized drive and

a control unit that is configured to derive an initial total load exerted by the motorized drive from at least one detected characteristic variable of the motorized drive in order to monitor for a trapping instance,

wherein the control unit is configured to derive the initial total load during a start phase at the beginning of an actuation operation of the adjusting device and to store the initial total load as the nominal load of the adjusting device

wherein the control unit is configured to determine whether trapping has occurred during a monitoring phase from a comparison between the nominal load and a total load which varies during the actuation operation of the adjusting device,

wherein the at least one detected characteristic variable of the motorized drive is used to determine the total torque of the motorized drive and, in the start phase, a nominal torque, to derive a trapping moment,

wherein the trapping moment is weighted with a weighting parameter that takes into account the mechanics of the adjusting device, in order to determine the resulting trapping force, and

wherein, in order to determine the weighting parameter, the trapping prevention guard makes measurements on a physical model and stores the measurement in a table, from which table the association of the resulting trapping moment to the resulting trapping force can be made.

7. A trapping prevention guard for an adjusting device, the trapping prevention guard comprising

a motorized drive and

a control unit that is configured to derive an initial total load exerted by the motorized drive from at least one detected characteristic variable of the motorized drive in order to monitor for a trapping instance,

wherein the control unit is configured to derive the initial total load during a start phase at the beginning of an actuation operation of the adjusting device and to store the initial total load as the nominal load of the adjusting device

wherein the control unit is configured to determine whether trapping has occurred during a monitoring phase from a comparison between the nominal load and a total load which varies during the actuation operation of the adjusting device,

wherein a spring model for a trapping instance is used as a basis for assessing whether trapping has occurred,

wherein the trapping prevention guard is configured to determine the value of at least one spring constant and to use value of the spring constant to determine whether trapping has occurred, and

wherein the trapping prevention guard is configured to use the absolute value of the spring constants or their profile or both to decide whether trapping has occurred.

8. A trapping prevention guard for an adjusting device, the trapping prevention guard comprising

a motorized drive and

a control unit that is configured to derive an initial total load exerted by the motorized drive from at least one detected characteristic variable of the motorized drive in order to monitor for a trapping instance,

wherein the control unit is configured to derive the initial total load during a start phase at the beginning of an actuation operation of the adjusting device and to store the initial total load as the nominal load of the adjusting device, and

wherein the control unit is configured to determine whether trapping has occurred during a monitoring phase from a comparison between the nominal load and a total load which varies during the actuation operation of the adjusting device, in which at least three load threshold values are defined and a value of the decision criterion is determined and evaluated between two load threshold values in each case.

9. A trapping prevention guard for an adjusting device, the trapping prevention guard comprising

a motorized drive and

a control unit configured to determine a characteristic variable of the motorized drive and to evaluate the characteristic variable using a first mathematical model in order to monitor for a trapping instance, and

wherein the control unit is configured to changeover to a second mathematical model that takes into account the trapping instance if there is a significant deviation in the characteristic variable for assessing whether trapping has occurred.