ETM Crankshaft Position Control for Lightweight Engine Starting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing internal combustion engine starting systems, particularly in small vehicles like snowmobiles, face challenges with weight, fuel efficiency, and handling due to the use of electric starting systems, which also require larger batteries and additional components, and lack efficient torque control and voltage management during starting and generating operations.
Innovation Solution
A system and method utilizing an electric turning machine (ETM) connected to the crankshaft, with a controller determining torque levels based on the absolute angular position of the crankshaft to efficiently start the engine using a smaller power source, incorporating vector control for precise torque delivery and fuel injection timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an electric starting system with battery and starter is used, then the engine can be started conveniently, but the vehicle weight increases and fuel efficiency decreases
Solution Approach 1:
The patent extracts the starting function from the traditional heavy battery-starter system and implements it through a lighter alternative using a capacitor bank and motor-generator unit, removing unnecessary weight while preserving the starting capability
Solution Approach 2:
The patent employs a capacitor bank that can be recharged from the vehicle's electrical system, using a lighter energy storage solution that is replenished during operation rather than relying on a heavy primary battery
2Reliability
If a larger motor-generator unit is used to provide sufficient starting torque, then the engine can be started reliably, but the device complexity and cost increase
Solution Approach 1:
The system determines the absolute angular position of the crankshaft before initiating the starting sequence, allowing the controller to pre-calculate the required torque profile and deliver it optimally through the motor-generator unit, ensuring reliable starting without excessive complexity
Solution Approach 2:
The patent incorporates feedback through absolute position sensing of the crankshaft, allowing the controller to monitor the starting process in real-time and adjust the motor-generator torque delivery to ensure reliable engine starting while optimizing system performance
3Reliability
If the starting sequence is extended to ensure proper ignition timing, then the engine can start more reliably, but the productivity and efficiency decrease
Solution Approach 1:
The system determines the absolute angular position of the crankshaft before starting, allowing the controller to pre-position the ignition and fuel injection systems for optimal timing, enabling rapid engine starting without compromising ignition reliability
Solution Approach 2:
The patent replaces traditional mechanical timing mechanisms with electronic control based on absolute position sensing, allowing precise ignition timing to be achieved through electronic synchronization rather than mechanical delays, thus reducing starting time while maintaining reliability
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
Enables a lighter and more efficient starting system that reduces weight and improves fuel efficiency by using a smaller power source, while ensuring effective torque delivery and precise fuel injection for efficient engine starting and operation.
Implementation Method 1
an electric turning machine (ETM) operatively connected to the crankshaft... Electric power is delivered to the ETM to rotate the crankshaft
Data Source
AI summary
An internal combustion engine (ICE) includes a crankshaft, a cylinder head defining in part a variable combustion chamber of the ICE, a direct fuel injector mounted on the cylinder head, a power source, an electric turning machine (ETM) rotating the crankshaft, an absolute position sensor providing an indication of an angular position of a rotor of the ETM, and an engine control unit (ECU) operatively connected to the absolute position sensor. The ECU controls a delivery of electric power from the power source to the ETM based on the angular position of the rotor of the ETM and causes the direct fuel injector to inject fuel directly in the combustion chamber at a time selected based on the angular position reached by the rotor of the ETM.