Radiation-Tolerant Flight Control Voting With Feedback Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aerospace vehicles operating in environments with high levels of ionizing radiation, such as cosmic rays and atmospheric neutrons, face challenges with control systems due to single event effects (SEEs) that cause errors in control blocks, leading to faulty output signals without correction, affecting system reliability and requiring downtime.
Innovation Solution
A control system with a voter and multiple control blocks, each equipped with a controller and feedback controller, uses integral, proportional, and derivative functions, along with voting algorithms to correct errors in real time, ensuring only correct output signals are provided to the external plant, thereby maintaining system operation without downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional control system with integral function is used in a radiation environment, then the system provides basic control functionality, but errors in control blocks are not corrected and the system requires downtime for error correction
Solution Approach 1:
The patent implements a feedback controller that receives the output signal from the controller, compares it with a reference signal and plant feedback signal, and generates a feedback control signal. This feedback mechanism enables the system to detect errors in control blocks and automatically correct them by adjusting the input signal to the controller, thereby maintaining continuous operation without requiring system downtime for error correction.
Solution Approach 2:
The control system performs self-diagnosis and self-correction through the feedback controller. When an error occurs in a control block, the feedback controller detects the discrepancy between the faulty output signal and the expected signal (derived from reference and plant feedback), and automatically corrects the error by adjusting the input signal, enabling the system to service itself without external intervention or downtime.
2Reliability
If modular redundancy control system is used to address radiation errors, then system reliability is improved, but system resources such as silicon in microprocessors and power consumption increase
Solution Approach 1:
Instead of using multiple redundant control blocks that would consume additional silicon and power, the patent employs a feedback controller that monitors the output of a single control block and automatically corrects errors. This feedback-based approach achieves the same reliability improvement as modular redundancy but with significantly reduced system resources, as it requires only one control block plus a relatively simple feedback controller rather than multiple full control blocks.
3Measurement precision
If voting algorithm is used to ensure only correct output signal is provided to plant, then control accuracy is maintained, but the control blocks cannot identify their own faulty output
Solution Approach 1:
The feedback controller enables each control block to indirectly detect its own fault status by comparing its output signal with the feedback control signal generated from the reference signal and plant feedback signal. When a control block produces a faulty output, the feedback controller detects the discrepancy and generates a corrective feedback signal, allowing the control block to identify that its output is faulty without requiring complex self-diagnosis circuitry.
Data Source
AI summary
A control system for an aerospace vehicle includes a voter and a plurality of control blocks. Each control block includes: a controller configured to receive an input signal and perform a control algorithm that includes an integral function on the input signal to provide an output signal; and a feedback controller that is configured to: receive the output signal from the controller, a reference signal from an external controller, and a plant feedback signal from an external plant; perform a feedback algorithm on the output signal to provide an feedback control signal; and perform a combinator algorithm using the reference signal, the plant feedback signal and the feedback control signal to provide the input signal to the controller; wherein the voter is configured to receive the output signals and perform a voting algorithm on the output signals to determine a control signal to provide to the external plant.