Vehicle Road Load Compensation for Acceleration Consistency
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Solution Overview
Problem
Traditional linear throttle mapping and fixed shift mapping in vehicles result in unpredictable acceleration due to varying road load conditions, leading to driver difficulty in controlling speed and acceleration, as the vehicle's response to accelerator pedal input changes with factors like mass, grade, and air resistance.
Innovation Solution
A vehicle road load compensation system that uses real-time sensor data to dynamically adjust throttle mapping, shift mapping, and torque converter lockup schedules to maintain a consistent relationship between accelerator pedal input and vehicle acceleration, by incorporating control units that update maps based on variables such as mass, drag, and grade load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional linear throttle mapping and fixed shift mapping are used, then the system is simple and easy to control, but the acceleration becomes unpredictable and inconsistent under varying road load conditions
Solution Approach 1:
The patent applies dynamics by transitioning from fixed throttle mapping to dynamic throttle mapping that adjusts in real-time based on road load conditions. The control system continuously monitors vehicle acceleration, pedal position, and road load factors to dynamically recalculate optimal throttle valve positions, ensuring consistent acceleration response despite changing conditions such as grade, wind, or vehicle mass.
Solution Approach 2:
The patent implements parameter changes by modifying the throttle mapping parameters based on detected road load conditions. When road load increases (e.g., uphill grade, headwind), the system adjusts throttle parameters to compensate, maintaining the desired relationship between pedal input and acceleration output. This involves changing mapping parameters dynamically rather than using fixed values.
2Reliability
If engine torque compensation logic is used to maintain acceleration, then acceleration consistency improves, but the system cannot respond to changes in road load and only affects engine torque
Solution Approach 1:
The patent applies segmentation by separating the acceleration control function into distinct components: engine torque control and transmission shift control. This allows independent optimization of each component's response to road load conditions. The system can adjust throttle mapping for torque control while simultaneously adjusting shift mapping for gear selection, providing versatile response capabilities that single-component systems cannot achieve.
Solution Approach 2:
The patent implements universality by creating a control system that handles multiple functions: engine torque management, transmission shift scheduling, and road load compensation. The dynamic mapping system serves as a universal solution that adapts to various road load conditions (grade, wind, mass changes) and works across different operating scenarios, making the system highly adaptable rather than specialized for a single function.
3Ease of operation
If dynamic throttle mapping and shift mapping adjustments are made in real-time, then acceleration consistency under varying road load is maintained, but the control system complexity increases
Solution Approach 1:
The patent applies feedback by continuously monitoring actual vehicle acceleration and comparing it to the expected acceleration based on pedal position. The control system uses this feedback to detect deviations caused by road load changes and automatically adjusts throttle and shift mapping parameters to correct the deviation. This closed-loop feedback mechanism maintains acceleration consistency while automating the complexity of real-time adjustments.
4Productivity
If fixed transmission shift mapping is used, then the transmission control is simple, but periods of flat acceleration occur before gear changes and acceleration feels stuck
Solution Approach 1:
The patent applies dynamics to shift mapping by transitioning from fixed shift points to dynamic shift scheduling. The system continuously monitors vehicle speed, acceleration, and road load conditions to determine optimal shift timing. When road load increases, the system delays upshifts to maintain acceleration momentum; when road load decreases, it can advance shifts for better fuel efficiency. This dynamic approach eliminates flat acceleration periods while adapting to varying conditions.
Data Source
AI summary
Disclosed is a vehicle road load compensation system that includes an accelerator pedal, a throttle, a transmission wherein a vehicle torque is generated proportional to the transmission gear and the motor power, and a control unit disposed within the vehicle and configured to receive real-time sensor data relating to the road load of the vehicle. The control unit includes a real-time throttle map relating the accelerator pedal position to the throttle position, such that a given accelerator pedal position directs a corresponding target throttle position. The control unit also includes a real-time shift map relating a desired transmission gear to a current transmission gear, vehicle speed, and throttle position. In response to the sensor data, the control unit updates the throttle map and shift map such that the vehicle torque is altered based on the road load of the vehicle. The controller may also update a real-time torque converter lockup map.