Optical Bale Length Sensor for Agricultural Balers

Solution Overview

Problem

Existing agricultural balers face inaccuracies and unreliability in determining bale length due to indirect and complex measurement methods, especially under extreme conditions like high temperatures and pressures.

Innovation Solution

The integration of an optical bale length sensor directly adjacent to the crop material in the baling chamber, which measures the bale length without physical contact using techniques like time of flight or Doppler principle, and optionally measuring twine lengths to account for post-compression expansion, providing accurate and reliable measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If indirect measurement methods (measuring wheels, optical sensors on wheels) are used to determine bale length, then device complexity is reduced, but measurement precision and reliability deteriorate under extreme conditions

Engineering Contradiction:

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical measuring wheels and contact-based sensors with a laser-based optical measurement system. The laser sensor emits light that reflects off the bale surface, and the reflected light is detected to calculate bale length and velocity. This substitution eliminates mechanical contact, reducing wear and failure under extreme conditions while maintaining high measurement precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces light as an intermediary medium between the sensor and the bale. Instead of direct mechanical contact or indirect wheel-based measurement, the laser beam serves as a non-contact intermediary that carries measurement information across the gap between the sensor and the moving bale, enabling accurate measurement without physical interaction.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If contact-based sensors are used to measure bale movement, then measurement precision may be maintained, but reliability deteriorates due to physical contact under extreme conditions

Engineering Contradiction:

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent replaces contact-based mechanical sensors with a laser-based optical system. The laser sensor measures bale position and velocity by detecting reflected light from the bale surface, eliminating all mechanical contact points that would wear, freeze, or fail under the extreme temperatures and pressures inside the baling chamber.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts the measurement function from the mechanical contact system and relocates it to a non-contact optical system. By taking the sensing function out of the harsh mechanical environment and placing it in a protected optical system outside the baling chamber, the reliability is significantly improved while maintaining measurement precision.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If mechanical linkages are used to synchronize plunger and slice pushing movements, then synchronization reliability is improved, but device complexity increases

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical linkages with an optical measurement and control system. Laser sensors continuously measure the position and velocity of the bale, and this data is fed to a control system that independently coordinates the plunger and slice pushing mechanisms, achieving synchronization through electronic control rather than mechanical coupling.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback-based synchronization system where laser sensors continuously monitor bale position and velocity, and this real-time information is used by the control system to adjust the timing and coordination of the plunger and slice pushing mechanisms. This closed-loop feedback approach achieves reliable synchronization without complex mechanical linkages.

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

The optical sensor system ensures precise and reliable bale length measurement, even in harsh environments, allowing for real-time process optimization and detection of bale shape deviations, enhancing the overall baling process accuracy and efficiency.

Implementation Method 1

measuring the length of the passing-by bale by detecting the surface of the crop material in the baling chamber

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Implementation Method 2

measuring the length of the passing-by bale by detecting the surface of the crop material in the baling chamber

Methodology Applied

Scientific EffectDoppler principle: Doppler Effect

Data Source

PatentUS10098283B2Baling chamber sensor

Publication Date: 2018.10.16

AI summary

An agricultural baler having a baling chamber and a pre-compression chamber, wherein the pre-compression chamber is adapted to periodically form a slice of crop material and push the slice towards the baling chamber into a first segment of the baling chamber, the baling chamber has a plunger provided for reciprocally moving in the baling chamber thereby compressing slices of crop material into a bale, wherein at least one optical bale length sensor is provided in the baling chamber for measuring the length of the bale.