System and method for control scheduling

• US 6,553,271 B1
• Filed: 05/28/1999
• Issued: 04/22/2003
• Est. Priority Date: 05/28/1999
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Morrell, John B.
• Primary Examiner(s): Picard, Leo
• Assistant Examiner(s): Garland, Steven R.
• Application Number:
  US09/322,431
• Time in Patent Office: 1,425 Days
• Field of Search: 700/28, 700/37, 700/40-43, 700/46, 700/52, 700/54, 700/55, 700/75, 700/76, 700/77, 60/39, 602/81, 604/49, 123/357, 180/178, 415/15
• US Class Current: 700/75
• CPC Class Codes: A61G 5/061 for climbing stairs
• CPC Class Codes: A61G 5/063 with eccentrically mounted wheels
• CPC Class Codes: A61G 5/1054 Large wheels, e.g. higher than the seat portion
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• CPC Class Codes: G05B 13/024 in which a parameter or coefficient is automatically adjusted to optimise the performance
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A system and method for controlling a device such that device operates in a smooth manner. The system may switch between control architectures or vary gain coefficients used in a control loop to control the device. As the architecture or gains are switched, the control signal may be smoothed so that the device does not experience an abrupt change in the control signal it receives. In one embodiment, the control signal may be smoothed by adding a decaying offset value to the control signal to create a smoothed control signal that is applied to the device.

Claims

1. A system for converting between a first operating mode and a second operating mode in a device, system comprising:

a control loop which utilizes gain coefficients associated with the first operating mode to control the system in the first operating mode and utilizes gain coefficients associated with the second operating mode when operating in the second operating mode;

a gain selector which causes the control loop to operate using the coefficients associated with the second operational mode at substantially the same instant that the device transitions from the first operational mode to the second operational mode, wherein the gain selector determines whether the control loop utilizes the coefficients associated with the first mode or the coefficients associated with the second mode based upon a current operational mode of the device;

a gain table which is accessed by the control loop and contains the coefficients which are associated with a current mode of operation; and

a smoother which smoothes the output of the control loop before a control signal created by the control loop is provided to the device, wherein the smoother adds a decaying offset value to the control signal.

2. A system for converting between a first operating mode and a second operating mode in a device, system comprising:

a control loop which utilizes gain coefficients associated with the first operating mode to control the system in the first operating mode and utilizes gain coefficients associated with the second operating mode when operating in the second operating mode;

a gain selector which causes the control loop to operate using the coefficients associated with the second operational mode at substantially the same instant that the device transitions from the first operational mode to the second operational mode, wherein the gain selector determines whether the control loop utilizes the coefficients associated with the first mode or the coefficients associated with the second mode based upon a current operational mode of the device;

a gain table which is accessed by the control loop and contains the coefficients which are associated with a current mode of operation; and

a smoother which smoothes the output of the control loop before a control signal created by the control loop is provided to the device, wherein the smoother adds a decaying offset value to the control signal, and wherein the offset value is determined by comparing a smoothed control signal applied to the device before the transition and a control signal created after the transition.

3. A method of smoothly switching between modes in a multi-modular apparatus, the method comprising steps of:

determining whether a mode change has occurred;

determining an offset value if the mode has changed; and

adding a decaying version of the offset value to a control signal before the control signal is applied to the apparatus to create a smoothed control signal;

applying the smoothed control signal to the apparatus; and

storing the smoothed control signal;

wherein a difference between the stored smoothed control signal and a control signal created after the apparatus has changed modes is used to determine the offset value.

4. The method of claim 3, further comprising steps of:

determining whether an offset value is currently decaying; and

replacing the currently decaying offset value with a new offset value when the apparatus changes modes.