Linear parameter varying model predictive control for engine assemblies

Patent metadata

Field	Value
Publication number	US-10060373-B2
Application number	US-201715408776-A
Country	US
Kind code	B2
Filing date	Jan 18, 2017
Priority date	Jan 18, 2017
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

An LPV/MPC engine control system is disclosed that includes an engine control unit connected to multiple sensors. The engine control unit receives, from the sensors, signals indicative of desired engine torque and engine torque output, and determines, from these signals, optimal engine control commands using a piecewise LPV/MPC routine. This routine includes: determining a nonlinear and a linear system model for the engine assembly, minimizing a control cost function in a receding horizon for the linear system model, determining system responses for the nonlinear and linear system models, determining if a norm of an error function between the system responses is smaller than a calibrated threshold, and if the norm is smaller than the predetermined threshold, applying the linearized system model in a next sampling time for a next receding horizon to determine the optimal control command. Once determined, the optimal control command is output to the engine assembly.

First claim

What is claimed:

1. A linear parameter varying (LPV) model predictive control (MPC) engine control system for an engine assembly, the LPV/MPC engine control system comprising:
an engine sensor configured to detect engine torque output of the engine assembly and generate a signal indicative thereof;
an input sensor configured to detect desired engine torque for the engine assembly and generate a signal indicative thereof; and
an engine control unit communicatively connected to the engine sensor, and the input sensor, the engine control unit being programmed to:
receive, from the engine and input sensors, signals indicative of a desired engine torque and an engine torque output;
determine, from the desired engine torque and engine torque output, an optimal control command using a piecewise LPV/MPC routine, including:
determine a nonlinear system model of engine torque for the engine assembly,
determine a linear system model for the engine assembly at a current engine operating condition,
minimize a control cost function in a receding horizon for the linear system model,
determine respective system responses for the nonlinear and linear system models with a current optimal control input,
determine if a norm of an error function between the system responses is smaller than a predetermined threshold, and
responsive to a determination that the norm is smaller than the predetermined threshold, apply the linearized system model in a next sampling time for a next receding horizon to determine the optimal control command; and

output the determined optimal control command to the engine assembly.

2. The LPV/MPC engine control system of claim 1 , wherein the piecewise LPV/MPC routine further includes, responsive to the determination that the norm is smaller than the predetermined threshold, executing the following in a continuous loop, starting at sample time k, until it is determined that the norm is not smaller than the predetermined threshold:
minimize the control cost function at next sampling times k+1, 2 . . . N in respective next receding horizons for the linear system model,
determine new respective system responses for the nonlinear and linear system models with the current optimal control input, and
determine if the norm of the error function between the new system responses is smaller than the predetermined threshold.

3. The LPV/MPC engine control system of claim 1 , wherein the piecewise LPV/MPC routine further includes, responsive to a determination that the norm is not smaller than the predetermined threshold:
determine a new linear system model for the engine assembly,
minimize the control cost function in a new receding horizon for the new linear system model,
determine new respective system responses for the nonlinear system model and the new linear system model with the current optimal control input, and
determine if the norm of the error function between the new system responses is smaller than the predetermined threshold.

4. The LPV/MPC engine control system of claim 1 , wherein determining the linear system model for the engine assembly includes calculating a system dynamic matrix A, B, C, D and V at a sample time k.

5. The LPV/MPC engine control system of claim 1 , wherein determining the linear system model includes linearizing the nonlinear system model at sample time k according to:

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Assignees

• Gm Global Tech Operations Llc

Inventors

• Wang Yue-Yun
• Long Ruixing
• Verdejo Julian R
• Chen Jyh-Shin

Classifications

• F02D2041/1412

  using a predictive controller · CPC title

• F02D2200/1002

  Output torque · CPC title

• F02D2250/18

  Control of the engine output torque · CPC title

• G05B13/042 Primary

  in which a parameter or coefficient is automatically adjusted to optimise the performance · CPC title

• F02D2200/602

  Pedal position · CPC title