Hybrid Drive Torque Control via Segmented Paths
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Solution Overview
Problem
Hybrid vehicles experience jerking vibrations due to rapid load changes and torque oscillations, which affect driving comfort, and existing methods struggle to precisely control the dynamics of internal combustion engine and electric machine torques, leading to inefficiencies and potential temperature peaks in the catalytic converter.
Innovation Solution
The method involves using the unfiltered total target torque to allocate setpoint torques directly to the internal combustion engine and electric machine, bypassing the guide shaper's filtering, allowing for high dynamic torque control with minimized ignition angle interventions, thereby achieving precise torque shaping and smooth transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the total setpoint torque is filtered by a guide shaper before allocation to drive units, then jerking vibrations are reduced, but the dynamic response of the hybrid drive is delayed and torque control precision is reduced
Solution Approach 1:
The patent segments the torque control into two independent paths: a slow path through the guide shaper for vibration reduction, and a fast path that bypasses the guide shaper for dynamic response. The operating strategy block allocates torque to drive units through both paths simultaneously, allowing the fast path to provide immediate torque changes while the slow path handles smooth transitions, thus resolving the contradiction between vibration reduction and dynamic response speed
Solution Approach 2:
The operating strategy block acts as an intermediary that receives the filtered total setpoint torque and the unfiltered lead setpoint torque, then combines them to generate setpoint torques for individual drive units. This intermediary process enables the system to benefit from both the vibration-reducing filtered torque and the responsive unfiltered torque without requiring additional filtering of the fast path signal
2Stability of the object's composition
If the guide shaper filters the total setpoint torque before allocation, then torque oscillations are reduced, but the precision of torque control at zero crossings is reduced
Solution Approach 1:
The patent segments torque control into filtered and unfiltered paths, allowing precise torque control at zero crossings through the unfiltered fast path while the filtered slow path handles overall stability. The operating strategy block independently manages torque allocation for each path, enabling precise control during transient operations without the smoothing effects that would reduce precision
3Ease of operation
If rapid load changes are avoided to reduce jerking vibrations, then driving comfort is improved, but the responsiveness of the hybrid drive to driver input is reduced
Solution Approach 1:
The patent segments the torque response into a slow filtered component for comfort and a fast unfiltered component for responsiveness. The guide shaper processes the total setpoint torque to generate a smooth, comfortable torque profile, while the fast path preserves rapid torque changes for immediate driver response. The operating strategy block combines these paths to achieve both comfort and responsiveness simultaneously
Data Source
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AI summary
The invention relates to a method for operating a hybrid drive comprising at least one first and a second drivingly connected driving machine (18, 20). According to said method, an actual torque (trq) of at least one of the driving machines (18, 20) is influenced with the aid of a reference governor (10) by generating a first setpoint torque (trqLeadEng) for a slow influence path and a second setpoint torque (trqDesEng) for a fast influence path for the first driving machine (18) as well as a setpoint torque (trqDesElm) for a fast influence path of the second driving machine (20) from a cumulative setpoint torque (trqDes). The lead setpoint torque (trqLeadEng) is obtained from the unfiltered cumulative setpoint torque (trqDes) so as to influence the slow influence path of the first driving machine (18) before the cumulative setpoint torque (trqDes) is processed in the reference governor (10).