Hot Spot Sensoring Controller for Linear Motor Position Control
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Solution Overview
Problem
Existing linear motor systems face challenges with position sensor failures, particularly in long linear motors, which lead to system instability and increased complexity, as well as limitations in sensorless control techniques due to environmental stresses and high-speed changes during applications like aircraft launch, where precise control is critical.
Innovation Solution
A Hot Spot Sensoring Controller that detects and reorganizes itself using distributed position sensors, a decision matrix, and switches to operate without sensors, employing mathematical models and observers for adaptive control, allowing for fault-tolerant operation and reduced sensor dependency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position sensors are extended along the entire length of the track to maintain control precision, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent divides the long linear motor track into multiple segments, each with its own position sensor. The controller selectively activates sensors based on the shuttle's location, using only the necessary portion of the sensor system at any given time. This segmentation approach maintains measurement precision where needed while reducing overall system complexity and cost.
Solution Approach 2:
The patent employs predictive control techniques that use mathematical models to anticipate future shuttle positions and pre-position the active sensor segments. By predicting where the shuttle will be next, the system prepares the appropriate sensor in advance, ensuring continuous precise measurement without requiring sensors along the entire track length.
2Measurement precision
If position sensors are used for vector control to maintain reliability, then control precision is improved, but system reliability deteriorates due to sensor fragility and failure risk
Solution Approach 1:
The patent implements different control strategies in different spatial locations along the track. In regions where sensors are installed, precise vector control is used. In sensorless regions, the system transitions to model-based control. This local differentiation allows the system to maintain high precision where sensors are present while improving overall reliability by reducing sensor dependency in critical areas.
Solution Approach 2:
The patent dynamically switches between sensor-based control and sensorless control modes based on real-time operating conditions and shuttle position. The controller adapts its control strategy, mathematical models, and active sensor segments according to the current state, enabling seamless transition between control modes and maintaining both precision and reliability across varying operational requirements.
3Device complexity
If sensorless control techniques are used to reduce complexity, then device complexity is reduced, but measurement precision and control accuracy deteriorate due to large air gap and end effects
Solution Approach 1:
The patent introduces mathematical models and observers as intermediary elements that bridge the gap between electrical measurements and mechanical position. These models compensate for the large air gap and end effects by calculating position and velocity from current and voltage measurements, combined with motor parameters and dynamic models, thereby achieving acceptable precision without direct position sensors.
Solution Approach 2:
The patent dynamically adjusts control parameters and mathematical model parameters based on operating conditions, shuttle position, and detected characteristics. By adapting parameters such as motor resistance, inductance, and back-EMF constants according to the current operating point, the sensorless control system maintains improved precision across varying speeds and positions despite the inherent limitations of sensorless operation.
4Area of stationary object
If discrete sensors are used per motor block to determine shuttle position, then measurement coverage is improved, but device complexity and cost increase
Solution Approach 1:
The patent designs the position sensor system to serve multiple functions: providing position feedback for block switching, enabling vector control, and supporting sensorless operation transitions. By making the sensor system multi-functional, the patent reduces the need for separate sensor systems for different control modes, thereby improving measurement coverage while limiting the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system maintains operational resilience and reduces sensor-related transients, enabling seamless performance even with sensor failures, and minimizes the need for extensive position feedback, thus enhancing reliability and control precision in demanding applications.
Implementation Method 1
The voltages are applied to the stator coils 102, 104, 106, 108 which generate currents in the conductors and ultimately generate electromagnetic force that propels shuttle 110 along the track
Data Source
AI summary
A system implementing a controller for linear motors is disclosed having a plurality of switches, a reorganization switch control detecting available hot spot sensors, encoder failures, and current sensor failures, and a storage storing a decision matrix having controller reorganization conditions. Upon detecting available hot spot sensors, encoder failures and recoveries, and current sensor failures and recoveries, the reorganization switch control reorganizes itself via configuring at least one of the switches based on information in said decision matrix to operate without available sensors and using available sensors.