Electric Trailer Drive Control Using Mass and Towing Force
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Solution Overview
Problem
Current systems for controlling electric drives in trailer vehicles are inefficient and require additional components to monitor and regulate the drive, leading to unstable driving conditions and reduced efficiency, especially in stability-critical situations.
Innovation Solution
A method that determines the current mass and driving force of the towing vehicle and trailer, using existing sensor systems, to calculate the acceleration request for the electric drive of the trailer, allowing for precise control without additional sensors, thereby reducing the risk of unstable driving and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors are installed on the towing vehicle to monitor the actual reaction of the trailer drive, then measurement precision is improved, but device complexity increases and costs rise
Solution Approach 1:
The control unit of the trailer vehicle independently determines the acceleration request based on data from its own sensors (wheel speed sensors, mass determination) and existing communication with the towing vehicle. This self-service approach eliminates the need for additional monitoring sensors on the towing vehicle, as the trailer's own control system performs the measurement and control functions.
Solution Approach 2:
Existing sensors and control units are made multi-functional. The trailer's control unit not only controls the electric drive but also determines acceleration requests and monitors driving stability. The wheel speed sensors serve both for speed measurement and for deriving acceleration information, eliminating the need for dedicated additional sensors.
2Stability of the object's composition
If iterative control is used to decelerate or accelerate the trailer vehicle, then stability is improved, but productivity decreases due to slower control response
Solution Approach 1:
The control unit determines the acceleration request in advance by calculating the difference between the desired acceleration (from towing vehicle communication) and the actual acceleration (from wheel speed sensors). This preliminary calculation of the acceleration request allows the system to proactively adjust the electric drive torque to maintain stability, rather than reacting iteratively after instability occurs.
Solution Approach 2:
The system continuously monitors wheel speeds to determine actual acceleration and compares it with the desired acceleration from the towing vehicle. This feedback loop allows the control unit to dynamically adjust the acceleration request and electric drive torque in real-time, maintaining stability while enabling faster response compared to iterative trial-and-error control.
3Use of energy by moving object
If the electric drive is used for recuperation, then energy efficiency is improved, but loss of time occurs due to delay in control response
Solution Approach 1:
The control unit continuously determines the acceleration request in advance by comparing desired and actual acceleration. This preliminary determination allows the system to proactively switch between motor and generator modes for optimal energy management, enabling timely recuperation actions without delay when braking or deceleration is required.
Solution Approach 2:
The system dynamically adjusts the acceleration request and electric drive operating mode based on real-time conditions. The control unit can rapidly transition between motor operation (for acceleration) and generator operation (for recuperation and braking) by dynamically modifying the acceleration request, enabling efficient energy recovery without time loss in stability-critical situations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables more efficient and targeted use of the electric drive, reducing the risk of unstable driving conditions and eliminating the need for additional sensors, thus lowering costs and enhancing the stability of the towing and trailer vehicle combination.
Implementation Method 1
An electric drive (52) of the trailer vehicle (16) is activated depending on the acceleration request, in particular in order to achieve a desired driving force through a torque with the electric drive (52)
Implementation Method 2
In generator operation, kinetic energy of a wheel connected to the electric motor is converted into electrical energy and this is fed into the energy store via the converter and stored there. This regenerative operation is also called recuperation
Data Source
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AI summary
The invention relates to a method for actuating an electrical drive (52) of a trailer vehicle (16) with a towing vehicle (12), comprising the steps of: determining (90) a current mass (92) of the trailer vehicle (12); determining (94) a current drive force of the towing vehicle (12); determining (102) an acceleration requirement (46) according to the current mass (92) and the current drive force (96); and actuating (118) the electrical drive (52) with an actuation signal (60) according to the acceleration requirement (46). The invention also relates to a control device (32, 48) for executing the method, a towing vehicle (12), a trailer vehicle (16) and a semi-trailer truck (10).