Adaptive Cruise Control Smooth Acceleration Profiles
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Solution Overview
Problem
Existing driving assist systems for vehicles lack smooth transitions between different speed settings and control modes, particularly when switching between speed and distance control, leading to abrupt acceleration and deceleration, which can be jarring for drivers and passengers.
Innovation Solution
A driving assist system that uses polynomial curves to create smooth, curved acceleration and speed profiles, allowing for seamless transitions between speed settings and control modes by processing data from sensors like cameras and lidar, ensuring continuous acceleration and zero jerk during mode changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing driving assist systems switch between speed and distance control modes, then the vehicle can adapt to different driving conditions, but the transitions cause abrupt acceleration and deceleration that are jarring for drivers and passengers
Solution Approach 1:
The patent applies curvature by replacing linear acceleration profiles with curved polynomial profiles (specifically cubic and quintic polynomials) that provide smooth transitions between control modes. The curved profiles ensure continuous acceleration and zero jerk during mode changes, eliminating the abrupt transitions that occur with linear profiles while maintaining adaptability between speed and distance control modes.
Solution Approach 2:
The system dynamically adjusts the acceleration profile based on the current control mode and desired speed changes. By using polynomial curves with variable coefficients that depend on initial and final speeds, the system creates adaptive, smooth transitions that respond to changing driving conditions while maintaining comfort during mode switches between speed and distance control.
2Device complexity
If linear acceleration profiles are used for speed changes, then the control system is simple to implement, but the transitions between speed settings are abrupt and uncomfortable
Solution Approach 1:
The patent replaces simple linear acceleration profiles with curved polynomial profiles (cubic and quintic polynomials) that provide smooth, continuous transitions. These curved profiles ensure zero jerk at all times during speed changes, eliminating the abrupt transitions of linear profiles while adding only moderate computational complexity through polynomial calculations.
Solution Approach 2:
The system changes the mathematical parameters of the acceleration profile from linear to polynomial form. By using polynomial equations with coefficients determined by initial and final speeds, the system transforms the simple linear control into a smoother polynomial-based control that maintains comfort while achieving the desired speed transitions.
Data Source
AI summary
A driving assist system for a vehicle includes a sensor disposed at the equipped vehicle and having a field of sensing exterior of the equipped vehicle and forward of the equipped vehicle. A controller includes a processor operable to process data captured by the sensor. The controller, responsive at least in part to an initial speed setting of an adaptive cruise control system of the equipped vehicle, controls acceleration of the equipped vehicle. The controller, responsive at least in part to processing by the processor of data captured by the sensor, determines presence of a target vehicle ahead of the equipped vehicle and determines an acceleration profile to adjust the speed of the vehicle from the current vehicle speed to a target speed. The controller adjusts the acceleration of the equipped vehicle responsive to the acceleration profile, which has smooth transitions between the initial speed setting and the target speed.