Electric Drive Vehicle Slip Ratio Control via Pitching Vibration Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large pitching vibrations in heavy electric drive vehicles, such as dump trucks, interfere with the calculation of the gradient of drive force relative to slip ratio, affecting wheel speed control, especially when vehicle weight changes with load.
Innovation Solution
Incorporating a filter to reduce the pitching vibrational frequency spectrum in the electric drive vehicle's control system, which includes a slip ratio calculation unit, torque command calculation unit, and drive force calculation unit, along with a weight detector and filter characteristic calculation unit to adjust the filter's output based on load, ensuring appropriate slip ratio control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If vehicle weight increases, then power and load capacity improve, but pitching vibration increases and interferes with slip ratio calculation
Solution Approach 1:
The patent extracts and removes the pitching vibrational frequency spectrum from the measured wheel speed and drive force signals using a filter. This separation allows the control system to eliminate the harmful vibration component while preserving the useful signal for accurate slip ratio calculation, directly resolving the contradiction between vehicle power and measurement precision.
Solution Approach 2:
The patent introduces a filter as an intermediary component between the measurement system and the control calculation. This filter acts as a mediator that processes the raw signals containing pitching vibration, removing the vibrational frequency spectrum before the data is used for slip ratio calculation, thereby enabling accurate measurements in heavy vehicles.
2Adaptability or versatility
If load changes, then vehicle weight changes, but the pitching vibrational frequency spectrum also changes making control difficult
Solution Approach 1:
The patent applies dynamics by making the filter characteristics adaptive to changing load conditions. The system dynamically adjusts the filter parameters based on the current pitching vibrational frequency spectrum, which changes with load. This allows the control system to maintain accuracy across different load conditions without requiring a completely different control strategy for each scenario.
3Reliability
If pitching vibration is large, then vehicle stability control becomes difficult, but adding complex filtering may increase system complexity
Solution Approach 1:
The patent replaces complex mechanical vibration isolation systems with an electronic signal processing approach. Instead of using mechanical dampers or isolators to reduce pitching vibration, the system uses electronic filtering of the measurement signals, which achieves the same effect of eliminating vibration interference while maintaining system simplicity and reliability.
Data Source
AI summary
Provided is an electric drive vehicle which can control wheel speed so as to achieve an appropriate slip ratio of the wheels even when pitching vibration of the vehicle is large. This electric drive vehicle is provided with electric motors (1, 4), drive wheels (3, 6), driven wheels (7, 8), an electric motor controller (50) for controlling the electric motors, and speed detectors (9-12) for detecting the wheel speed of the drive wheels and the driven wheels. The electric motor controller is provided with: a slip ratio calculation unit (21) which calculates the slip ratio of the drive wheels from the wheel speed detected values detected by the speed detectors; a torque command calculation unit (20) which calculates torque commands for the drive wheels; a drive force calculation unit (19) which, from the wheel speed detected values of the drive wheels and the torque commands of the drive wheels, calculates the drive force generated in the drive wheels; and filters (54, 55) which reduce the pitching vibration frequency components of the vehicle included in the slip ratio and the drive force.