Hybrid Vehicle Engine Starting Control System for Cold Temperatures
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Solution Overview
Problem
Conventional hybrid electric vehicle (HEV) starting systems face challenges in cold temperatures due to limited battery performance, which leads to undesirable vibrations and oscillations caused by the resonance frequency of the damper, and existing solutions increase system complexity and cost.
Innovation Solution
A method and system that adjust engine speed during starting using a control system to reach a fixed value or time-based threshold, transitioning out of engine start mode to minimize time in the resonance frequency zone, thereby reducing vibrations and oscillations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the engine is started using conventional battery power in cold temperatures, then the engine can be started, but the battery performance is limited and excessive power usage occurs
Solution Approach 1:
The control system dynamically adjusts engine speed parameters during the starting process. By optimizing the cranking speed and transition timing, the system reduces the energy demand on the battery while ensuring reliable engine start in cold conditions. The fixed value threshold and time-based threshold work together to optimize the starting profile.
Solution Approach 2:
The control system continuously monitors engine speed and compares it against predetermined thresholds. Based on this feedback, the system adjusts the starting process in real-time, transitioning from engine start mode to normal operating mode when thresholds are met, thereby optimizing battery power usage while maintaining starting reliability.
2Use of energy by moving object
If the engine starts slowly to conserve battery power, then battery power usage is reduced, but the engine remains in the resonance frequency zone longer causing increased vibrations
Solution Approach 1:
The control system rapidly accelerates the engine through the resonance frequency zone by implementing a controlled transition to higher speeds once the fixed value threshold is reached. This strategy minimizes the time spent in the harmful resonance frequency range, reducing vibrations and oscillations while still conserving battery power overall.
Solution Approach 2:
The starting process is divided into distinct phases: an initial acceleration phase to reach the fixed value threshold, followed by a transition phase to normal operating mode. This periodic structure allows the engine to efficiently pass through the resonance zone without prolonged exposure, balancing power consumption and vibration reduction.
3Reliability
If existing solutions like additional batteries or self-heating systems are used, then cold starting performance is improved, but system complexity and cost increase
Solution Approach 1:
The control system utilizes the existing battery and engine components to achieve improved cold starting performance. By intelligently managing the starting process through optimized speed control and threshold-based transitions, the system eliminates the need for additional batteries, heating elements, or complex auxiliary systems, thereby maintaining simplicity while enhancing reliability.
Data Source
AI summary
The present invention provides a system and method for starting a vehicle in a cold temperature environment and minimizing the time spent by the vehicle within a resonance frequency zone during operation. The present invention includes a method of starting a vehicle engine comprising adjusting the speed of the engine during an engine start mode in accordance with a fixed value threshold. The method also includes determining whether the engine speed has reached the fixed value threshold or whether a time-based threshold has been reached. The method further includes transitioning out of the engine start mode into a normal operating mode when either the fixed value threshold or the time-based threshold has been reached.