Wastegate Actuator Position Control via H-Bridge Current Sensing
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Solution Overview
Problem
The existing method for monitoring the position of a wastegate in a turbocharger requires a position sensor, which is costly and prone to malfunctions due to wear or defective electrical contacts, and necessitates three connection pins to the Engine Control Unit (ECU), contradicting the trend of minimizing connections.
Innovation Solution
A method that eliminates the need for a position sensor by using the measurement of electrical current through an H bridge to determine the torque and displacement of the electrical actuator, allowing for the estimation of the wastegate position through integration, and applying correction factors to achieve precise control of the valve's position without a physical sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a position sensor is used to monitor the wastegate position, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical/electrical position sensor system with an electromagnetic measurement system. By measuring the current through the H-bridge that controls the electrical actuator, the system infers wastegate position without physical sensors, thereby reducing device complexity while maintaining measurement capability
Solution Approach 2:
The patent introduces current measurement as an intermediary parameter to indirectly determine wastegate position. Instead of directly measuring position with a sensor, the system measures the electrical current flowing through the actuator's H-bridge, which serves as a mediator that correlates with position through the actuator's electrical characteristics
2Measurement precision
If a position sensor is installed on the wastegate, then position monitoring accuracy is improved, but reliability decreases due to wear and defective contacts
Solution Approach 1:
The patent eliminates mechanical wear components by replacing the position sensor with an electrical measurement system. The H-bridge current measurement requires no moving parts or contact wear, thereby significantly improving reliability while maintaining the ability to monitor wastegate position
Solution Approach 2:
The patent utilizes the existing electrical actuator and H-bridge circuitry to provide position information, rather than adding a separate sensing system. The actuator's own electrical characteristics are leveraged to generate position data, eliminating the need for additional reliability-prone components
3Measurement precision
If three connection pins are used for position sensor feedback to the ECU, then measurement precision is improved, but the number of connections increases
Solution Approach 1:
The patent merges the position measurement function with the existing actuator control circuitry. By using the same H-bridge that controls the actuator to also measure position through current sensing, the system combines two functions into one circuit, eliminating separate connection pins to the ECU
Solution Approach 2:
The H-bridge circuit is given multiple functions: it both controls the electrical actuator and measures the wastegate position through current sensing. This multi-functionality eliminates the need for dedicated position sensor connections, reducing the number of pins required at the ECU
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
This approach reduces hardware costs, minimizes connection requirements, and enhances reliability by using existing current measurement tools to accurately regulate the wastegate position, providing a cost-effective and fault-tolerant solution for turbocharger control.
Implementation Method 1
an H bridge is present in the circuit for controlling the rotation of the electric motor to permit said electric motor to rotate in both rotational directions
Implementation Method 2
an electrical actuator of the electric motor type controls such a valve
Data Source
AI summary
Method for regulating the control of an electrical wastegate actuator controlled via an H bridge to permit displacement of the wastegate in its closure and opening directions according to whether the current passes through the actuator in one or opposite direction, includes:determining a set position which the wastegate has to reach, and an activation time of the actuator defining a monitoring time;applying a control signal to the actuator to displace the valve into the set position;measuring the current passing through the H bridge and applying a correction factor to the current to obtain the motor torque;obtaining the displacement speed of the wastegate by integration of the motor torque;obtaining the position reached by the wastegate at the end of the monitoring time by integration of the speed;comparing the position reached with the set position; andrepeating the method until the set position is reached.