Adaptive Cruise Torque Control for Slope-Stable Following Distance
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Solution Overview
Problem
Conventional adaptive cruise control systems fail to accurately adjust torque values to maintain a constant following distance when the subject vehicle is traveling on varying slopes or experiencing changes in pitch, leading to suboptimal torque adjustments on upward sloping or flat surfaces.
Innovation Solution
The system employs slope-detecting and pitch-detecting sensors connected to the electronic control unit (ECU) to calculate a new desired torque value, which adjusts the throttle valve position in gasoline engines or fuel injection in diesel engines, ensuring optimal torque management for maintaining a constant following distance relative to a target vehicle across different surface slopes and vehicle pitches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ACC systems adjust torque based on standard deceleration models calibrated for downward slopes, then the system can maintain following distance on downward slopes, but the system over-compensates and requests excessive torque reduction on upward sloping or flat surfaces
Solution Approach 1:
The system dynamically adjusts the deceleration model based on real-time slope detection. When an upward slope is detected, the system modifies the torque reduction calculation to account for the slope angle, transitioning from a static downward-slope-calibrated model to a dynamic model that adapts to the current terrain condition. This prevents over-compensation by making the torque adjustment proportional to the actual slope rather than applying a fixed model.
Solution Approach 2:
The system changes the torque reduction parameter based on detected slope conditions. Instead of using a fixed torque reduction value calibrated for downward slopes, the system modifies the torque parameter dynamically - reducing the torque reduction amount when upward slopes are detected and maintaining appropriate reduction when downward slopes are present. This parameter adaptation ensures accurate torque management across varying terrain.
2Productivity
If the ACC system uses a deceleration model calibrated for downward sloping environments, then torque reduction can be effective on downward slopes, but the system cannot accurately identify optimal torque values on upward sloping or flat surfaces
Solution Approach 1:
The system incorporates slope detection feedback into the torque calculation process. The slope detector provides real-time information about the terrain inclination, which feeds back to the ACC controller to modify torque requests. This feedback loop enables the system to identify optimal torque values by continuously adjusting based on actual slope conditions rather than relying on a predetermined calibration model.
Solution Approach 2:
The system performs preliminary slope detection and pitch measurement before calculating torque adjustments. By detecting the slope and vehicle pitch in advance, the system can pre-calculate the appropriate torque reduction amount specific to the current terrain condition, ensuring accurate torque identification before the deceleration maneuver begins rather than relying on post-calibration models.
Data Source
AI summary
Disclosed herein are systems and methods, implementable in a vehicle equipped with adaptive cruise control, for maintaining in a subject vehicle substantially constant following distance relative to a preceding target vehicle where there has been a change in slope of a surface on which the subject vehicle is travelling and/or where pitch of the subject vehicle has changed. Systems and methods disclosed herein may maintain such substantially constant following distance by managing engine torque. Such engine torque management effective for maintaining substantially constant following distance relative to a preceding target vehicle, notwithstanding change in driving surface slope and/or change in pitch of the subject vehicle, may be realized, according to the subject vehicle's torque map, based on data received into the subject vehicle's electronic control unit through sensors for detecting surface slope and sensors for detecting vehicle pitch, which may be located on the subject vehicle.