11,295 research outputs found
A Control-Oriented Notion of Finite State Approximation
We consider the problem of approximating discrete-time plants with
finite-valued sensors and actu- ators by deterministic finite memory systems
for the purpose of certified-by-design controller synthesis. Building on ideas
from robust control, we propose a control-oriented notion of finite state
approximation for these systems, demonstrate its relevance to the control
synthesis problem, and discuss its key features.Comment: IEEE Transactions on Automatic Control, to appea
H∞ control of nonlinear systems: a convex characterization
The nonlinear H∞-control problem is considered with an emphasis on developing machinery with promising computational properties. The solutions to H∞-control problems for a class of nonlinear systems are characterized in terms of nonlinear matrix inequalities which result in convex problems. The computational implications for the characterization are discussed
Observer-based correct-by-design controller synthesis
Current state-of-the-art correct-by-design controllers are designed for
full-state measurable systems. This work first extends the applicability of
correct-by-design controllers to partially observable LTI systems. Leveraging
2nd order bounds we give a design method that has a quantifiable robustness to
probabilistic disturbances on state transitions and on output measurements. In
a case study from smart buildings we evaluate the new output-based
correct-by-design controller on a physical system with limited sensor
information
On Model Based Synthesis of Embedded Control Software
Many Embedded Systems are indeed Software Based Control Systems (SBCSs), that
is control systems whose controller consists of control software running on a
microcontroller device. This motivates investigation on Formal Model Based
Design approaches for control software. Given the formal model of a plant as a
Discrete Time Linear Hybrid System and the implementation specifications (that
is, number of bits in the Analog-to-Digital (AD) conversion)
correct-by-construction control software can be automatically generated from
System Level Formal Specifications of the closed loop system (that is, safety
and liveness requirements), by computing a suitable finite abstraction of the
plant.
With respect to given implementation specifications, the automatically
generated code implements a time optimal control strategy (in terms of set-up
time), has a Worst Case Execution Time linear in the number of AD bits , but
unfortunately, its size grows exponentially with respect to . In many
embedded systems, there are severe restrictions on the computational resources
(such as memory or computational power) available to microcontroller devices.
This paper addresses model based synthesis of control software by trading
system level non-functional requirements (such us optimal set-up time, ripple)
with software non-functional requirements (its footprint). Our experimental
results show the effectiveness of our approach: for the inverted pendulum
benchmark, by using a quantization schema with 12 bits, the size of the small
controller is less than 6% of the size of the time optimal one.Comment: Accepted for publication by EMSOFT 2012. arXiv admin note:
substantial text overlap with arXiv:1107.5638,arXiv:1207.409
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