Driveline Pedal Mapping for Load-Adaptive Standstill Force Limiting
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Solution Overview
Problem
The drivability of trucks is affected by the inconsistent limitation of propulsion force based on load weight, leading to unpredictable driving experiences due to varying pedal mappings, especially at standstill.
Innovation Solution
A control unit adjusts the driveline propulsion force to a maximal threshold value based on vehicle weight, road inclination, and acceleration, adapting pedal mapping to ensure each pedal position corresponds to a predefined percentage of this threshold, independent of the actual threshold value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the propulsion force is limited based on vehicle weight to prevent loss of control, then vehicle safety is improved, but the driving experience becomes inconsistent and unpredictable
Solution Approach 1:
The patent implements dynamic adaptation of pedal mapping based on real-time vehicle weight detection. The control unit adjusts the relationship between pedal position and propulsion force request according to the actual load, transforming a static limitation system into a dynamic one that maintains consistent driver feedback across different loading conditions while still enforcing safety limits.
Solution Approach 2:
The system changes the parameter of pedal mapping (the functional relationship between pedal position and force request) based on vehicle weight. By detecting weight and adapting the mapping parameters, the system ensures that each pedal position corresponds to the same percentage of the maximal force threshold regardless of load, thereby maintaining driving consistency while preserving safety limits.
2Ease of operation
If the propulsion force limitation is adapted to vehicle weight, then driving consistency is improved, but the system complexity increases
Solution Approach 1:
The control unit automatically detects vehicle weight and performs self-adjustment of the pedal mapping without requiring manual intervention or complex external calibration systems. The system serves itself by using its own sensors and processing capabilities to adapt the propulsion force limitation, thereby improving driving consistency while minimizing the added complexity.
3Measurement precision
If the maximal force threshold is calculated based on vehicle weight, road inclination, and acceleration, then force limitation accuracy is improved, but the calculation complexity increases
Solution Approach 1:
The control unit calculates the maximal force threshold in advance based on detected vehicle weight, assumed road inclination, and reference acceleration before the driver operates the pedal. This preliminary calculation allows the system to have the threshold ready for immediate comparison with actual force requests, improving accuracy without requiring complex real-time calculations during dynamic driving situations.
Data Source
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AI summary
The invention relates to a vehicle (1) comprising a driveline (7) which comprises a motor (15) configured to provide a propulsion force to propel the vehicle, a pedal (11) configured to control a power provided by the motor when a driver press the pedal to tilt the pedal in different positions, and a control unit (9) configured to limit, at standstill, in function of an estimation of a weight of the vehicle, the propulsion force provided by the driveline to a maximal force threshold value. The control unit is configured to adapt, at standstill, the pedal mapping so that each position of the pedal corresponds to a predefined percentage of the maximal force threshold value, independently of the maximal force threshold value. The maximal force threshold value is calculated as a function of the weight of the vehicle, a reference inclination of the road and a reference acceleration of the vehicle. The invention further relates to a corresponding method.