Cab Suspension Control Using Road Information

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Solution Overview

Problem

Conventional methods for controlling driver's cab suspension in commercial vehicles fail to adequately balance comfort and safety, particularly due to delayed adjustments in response to changing driving dynamics and insufficient coupling between chassis and cab mounting systems, leading to undesirable pitching and rolling movements.

Innovation Solution

A method and device that anticipatorily adjust the spring-damper device of the driver's cab suspension based on road information ahead, using adjustable semi-active or active dampers to proactively set optimal damping properties and inclinations, thereby enhancing comfort and safety by preemptively addressing road conditions such as bumps and curves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If passive damper systems are used with fixed damping characteristics, then the device complexity is reduced, but the adaptability to different driving conditions deteriorates

Engineering Contradiction:
Improvedamping system complexityVSAvoidadaptability to driving conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system uses road information detection devices (cameras, sensors) to detect upcoming road conditions in advance, and the control unit pre-adjusts the damping characteristics before the vehicle encounters the actual road irregularities. This preliminary action allows the suspension to be optimally prepared for upcoming bumps, curves, or uneven surfaces, improving comfort without requiring complex real-time reaction systems

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs adjustable spring-damper devices that can dynamically change their damping characteristics based on detected road conditions. The system transitions from static passive dampers to dynamically adjustable semi-active or active dampers, allowing real-time optimization of suspension performance for different driving situations while maintaining manageable system complexity through controlled adjustability

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If feedback systems adjust damping force based on detected driving dynamics, then the adaptability improves, but the response time deteriorates due to detection and evaluation delays

Engineering Contradiction:
Improvedamping adjustment responsivenessVSAvoidresponse delay
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

Instead of waiting for feedback from vehicle sensors detecting actual cab movements, the system proactively detects road conditions ahead using forward-facing cameras and sensors. The control unit calculates optimal damping settings in advance and applies them before the vehicle encounters the road irregularities, eliminating the time delay inherent in feedback systems that react to already-occurred movements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system introduces road information detection devices as an intermediary between the road conditions and the suspension system. These devices detect upcoming road irregularities and transmit this information to the control unit, which then adjusts the damping characteristics accordingly. This intermediary approach allows the system to anticipate and prepare for road conditions rather than react to them, significantly reducing response time

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the driver's cab is resiliently mounted on the chassis frame, then the comfort is improved by damping vibrations, but the stability deteriorates due to undesirable pitching and rolling movements

Engineering Contradiction:
Improvedriver comfortVSAvoidcab stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The system uses adjustable spring-damper devices that can dynamically modify their damping characteristics based on detected road conditions. When upcoming curves or uneven roads are detected, the system increases damping forces to reduce pitching and rolling movements, maintaining cab stability. On smooth roads, the damping is reduced to allow better vibration isolation, maintaining comfort. This dynamic adjustment resolves the contradiction between comfort and stability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit changes the damping parameters of the spring-damper devices based on detected road conditions. By adjusting damping force parameters in response to upcoming road irregularities, the system optimizes the balance between comfort and stability. The damping characteristics are modified to counteract expected pitching and rolling movements while maintaining vibration damping benefits

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If semi-active or active dampers are used to control cab vibrations, then the comfort is improved, but the device complexity increases

Engineering Contradiction:
Improvevibration damping performanceVSAvoidsuspension system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system uses road information detection to pre-determine optimal damping settings before the vehicle encounters road irregularities. This approach allows the use of semi-active or active dampers with controlled complexity, as the system only needs to adjust to pre-calculated settings rather than requiring complex real-time control algorithms. The preliminary detection and calculation simplifies the control requirements while maintaining improved vibration damping performance

Inventive Principle:
Principle #10Preliminary action

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 approach significantly improves comfort and safety by allowing for proactive adjustments to the driver's cab suspension, reducing the impact of road irregularities and cornering forces, thereby enhancing the overall driving experience and safety.

Implementation Method 1

such shock absorbers can be based on (proportional) adjustment valves that change the oil flow

Methodology Applied
Scientific EffectHydraulic flow control: Hydraulic Press

Implementation Method 2

on magneto- or electrorheological fluids, with a magnetic or electric field influencing the viscosity of the fluid and thus the damping force

Methodology Applied
Scientific EffectMagneto-rheological effect: Magnetorheological Fluid

Implementation Method 3

on magneto- or electrorheological fluids, with a magnetic or electric field influencing the viscosity of the fluid and thus the damping force

Methodology Applied
Scientific EffectElectro-rheological effect: Electrorheological Effect

Data Source

PatentEP3323699B1Method and device for controlling or regulating a cab suspension of a motor vehicle
Publication Date: 2019.07.31 MAN TRUCK & BUS SE
  • EP3323699B1 patent drawingFigure 1
  • EP3323699B1 patent drawingFigure 2
  • EP3323699B1 patent drawingFigure 3

AI summary

The invention relates to a method for controlling or regulating the cab mounting of a motor vehicle, in particular a commercial vehicle. The invention further relates to a device for controlling or regulating the cab mounting of a motor vehicle. According to the method for controlling or regulating the cab mounting of a motor vehicle, the control or regulation of the cab mounting is carried out depending on at least one piece of road information (S1) obtained, which relates to a road segment ahead in the direction of travel of the motor vehicle, such that an adjustment (S2) of a spring-damper assembly of the cab mounting is made depending on the obtained road information. This enables a preventive adjustment of the spring-damper assembly of the cab mounting, thereby increasing comfort in the cab.