Hydraulic Towing Control via Optical Speed Detection

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Solution Overview

Problem

Existing systems for controlling tractor drive slip in agricultural tractors are complex, costly, and imprecise, particularly when determining actual speed and environmental conditions, leading to potential stalling and getting stuck in wet soils.

Innovation Solution

A device with a hydraulic actuating unit featuring two distance determination sensors and an evaluation unit to determine actual speed by measuring soil profiles and time offsets, connected to a hydraulic operating system for adjusting the towing device's operation, including an acceleration sensor for additional speed measurement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar or ultrasonic sensors are used to measure actual speed based on the Doppler effect, then drive slip determination accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedrive slip determination accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential measurement function from complex radar/ultrasonic speed measurement systems and implements it using simple optical sensors (LEDs and photodetectors) that detect ground reflection patterns. This removes the need for expensive Doppler effect-based systems while maintaining the ability to determine actual vehicle speed and calculate drive slip accurately.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive, complex radar or ultrasonic sensors with inexpensive optical components (LEDs and photodetectors) that can be easily manufactured and replaced. These simple optical sensors provide sufficient measurement capability for drive slip determination without the high cost and complexity of electromagnetic wave-based systems.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If multiple sensors and complex control loops are added to improve reliability in wet soil conditions, then tractor performance is improved, but device complexity and cost increase

Engineering Contradiction:
Improveoperational reliability in wet soilVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a self-regulating system where the comparison between actual speed (measured by simple optical sensors) and target speed automatically triggers plow depth adjustments. The system uses basic feedback control without complex algorithms or multiple sensor types, allowing the tractor to self-adjust to prevent getting stuck in wet soil while maintaining simplicity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The simple optical sensor system serves multiple functions: it measures actual vehicle speed, detects ground conditions indirectly through speed variation, and provides input for both drive slip calculation and plow depth control. This multi-functionality reduces the need for separate specialized sensors for different measurement tasks.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If simple speed measurement methods are used, then device complexity is reduced, but measurement precision and reliability deteriorate

Engineering Contradiction:
Improvesystem simplicityVSAvoidactual speed determination accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses continuous feedback from the optical sensors that monitor ground reflection patterns as the vehicle moves. By tracking changes in reflected light patterns over time and comparing actual speed with target speed, the system achieves accurate speed measurement and automatic adjustment, ensuring reliability without complex hardware.

Inventive Principle:
Principle #23Feedback

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 solution provides a reliable, accurate, and simple method to control drive slip, reducing time and fuel consumption, minimizing tire wear, protecting the soil, and preventing the tractor from getting stuck, while ensuring efficient operation.

Implementation Method 1

Both distance sensors can each have a transmitter and a receiver and, upon request from the evaluation unit, emit, for example, light waves or sound waves towards the ground and receive the sound waves reflected from the ground

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

The speed detection unit additionally includes an acceleration sensor (18) which is connected to the evaluation unit (10) via data transmission

Methodology Applied
Scientific EffectAcceleration measurement: Accelerometer

Data Source

PatentEP3146822B1Device and method for controlling the operation of a hydraulically actuated towing device on a vehicle
Publication Date: 2019.03.20 ROBERT BOSCH GMBH
  • EP3146822B1 patent drawingFigure 1
  • EP3146822B1 patent drawingFigure 2~3
  • EP3146822B1 patent drawingFigure 4

AI summary

The invention relates to a device (1) for a vehicle (2), in particular a tractor, with a hydraulic actuation unit (3) for controlling the operation of a towing device (4) on the vehicle (2), comprising at least a speed detection unit (5) with two distance sensors (8, 9) positioned one behind the other in the direction of travel (6) of the vehicle (2) and directed towards the ground (7), and an evaluation unit (10), as well as data-conducting connections (11) to a vehicle operating system (12) and a hydraulic operating system (13) associated with the hydraulic actuation unit (3). Furthermore, a method is proposed in which the actual speed of the vehicle (2) and the current drive slip can be determined by means of such a speed detection unit (5), and the drive slip can be adjusted as required by suitable operation of the hydraulic actuation unit (3).