Autonomous Vehicle Speed Control Reducing Jerk via Look-Ahead Mediation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing driver-assist control devices generate target vehicle speeds that lead to unnecessary acceleration and significant jerk when transitioning from acceleration to deceleration, as they prioritize vehicle speed limits and headway distances set by drivers over impending deceleration needs.
Innovation Solution
A method and device that forecast future vehicle speed command values and select the lowest value among them to generate a target vehicle speed, using a system comprising sensors, autonomous driving control units, and vehicle speed command generation units to calculate and mediate look-ahead vehicle speed command values, thereby reducing unnecessary acceleration and jerk during transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lower of the vehicle speed limit and target vehicle speed based on headway distance is selected, then vehicle speed control is simplified, but unnecessary acceleration occurs and jerk increases during transition from acceleration to deceleration
Solution Approach 1:
The patent calculates look-ahead vehicle speed command values at future time points (t+Δt1, t+Δt2, etc.) before the current time t, and selects the minimum value among these future values. This preliminary action at future time points allows the system to anticipate upcoming deceleration needs and avoid unnecessary acceleration at the current time, thereby reducing jerk during transitions.
Solution Approach 2:
By selecting the minimum vehicle speed command value from future time points, the patent preemptively counteracts potential unnecessary acceleration that would occur if only current speed commands were considered. This preliminary anti-action ensures that the vehicle does not accelerate when future conditions require deceleration, thus preventing harmful jerk during acceleration-deceleration transitions.
2Speed
If target vehicle speed is generated based on current vehicle speed command values only, then response time is reduced, but unnecessary acceleration occurs when deceleration is upcoming
Solution Approach 1:
The system performs preliminary calculations of vehicle speed command values at future time points (t+Δt1, t+Δt2, etc.) before making the current control decision. By evaluating future speed requirements in advance and selecting the minimum value, the system maintains fast response while avoiding unnecessary acceleration that would result from considering only current speed commands.
3Manufacturing precision
If vehicle speed command values are adjusted frequently to match real-time conditions, then control precision is improved, but more frequent acceleration-deceleration transitions increase jerk
Solution Approach 1:
By calculating and selecting the minimum vehicle speed command value from multiple future time points before applying it at the current time, the patent reduces the frequency of control adjustments. This preliminary action ensures that the selected speed command already accounts for upcoming conditions, thereby maintaining control precision while reducing frequent acceleration-deceleration transitions and associated jerk.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Unnecessary acceleration is suppressed and moreover jerk at a time of transition from acceleration to deceleration is reduced when traveling using driver-assistance. A device for generating a target vehicle speed of a driving-assisted vehicle (autonomously driven vehicle) equipped with an autonomous driving control unit (2) (controller) that includes a plurality of vehicle speed command generation units (21) and generates a target vehicle speed for when the vehicle is to travel/stop, wherein the autonomous driving control unit (2) comprises a look-ahead vehicle speed command calculation unit (22) and a lowest vehicle speed command mediation unit (23). The look-ahead vehicle speed command calculation unit (22) calculates a look-ahead vehicle speed command value that comes after the elapse of a prescribed amount of time from a present time for each vehicle speed command value generated by the plurality of vehicle speed command generation units (21). The lowest vehicle speed command mediation unit (23) selects a lowest value among the plurality of look-ahead vehicle speed command values calculated by the look-ahead vehicle speed command calculation unit (22).