Adaptive Machine Speed Control for Cross-Track Error Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Modern mobile machinery, such as agricultural and earthmoving machines, face challenges in maintaining precise control over velocity and horizontal steering due to sources like measurement device limitations, imprecise steering linkages, and external environmental factors, leading to cross track errors that affect efficiency and soil compaction.

Innovation Solution

A computer-implemented method that captures sensor data to estimate the actual position of the machine, calculates cross track errors, and adjusts velocity to reduce these errors by comparing actual and target cross track error metrics, using a velocity control loop in conjunction with a steering control loop to achieve optimal horizontal control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the machine operates at higher velocity to increase productivity, then productivity improves, but cross track error increases leading to reduced manufacturing precision

Engineering Contradiction:
Improveoperating velocityVSAvoidhorizontal control accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system continuously measures actual position using sensors (GNSS, IMU, wheel encoders) and compares it to the desired guidance path, calculating cross-track error in real-time. This feedback loop enables dynamic velocity adjustment to maintain precision while operating at high speeds, resolving the contradiction between productivity and manufacturing precision.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The velocity control system dynamically adjusts operating velocity based on real-time cross-track error measurements and machine dynamics characteristics. By making velocity adaptive rather than fixed, the system can operate at higher average speeds while automatically reducing velocity when precision requirements demand, thus resolving the contradiction between productivity and manufacturing precision.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If steering linkage precision is increased to improve horizontal control, then manufacturing precision improves, but device complexity increases

Engineering Contradiction:
Improvehorizontal control accuracyVSAvoidsteering linkage complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system replaces complex mechanical steering precision requirements with electronic control and sensor-based feedback. Instead of relying solely on precision mechanical linkages, the invention uses GNSS receivers, IMUs, and electronic velocity control to achieve high horizontal control accuracy, thereby reducing mechanical complexity while improving or maintaining precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The introduction of electronic sensors and control systems acts as an intermediary between the operator and the steering mechanism. This intermediary layer provides real-time position feedback and automated velocity adjustment, achieving high precision horizontal control without requiring overly complex mechanical steering linkages.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If measurement device precision is increased to reduce cross track error, then manufacturing precision improves, but device complexity increases

Engineering Contradiction:
Improveposition measurement accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system uses a multi-functional sensor suite where GNSS receivers, IMUs, and wheel encoders serve multiple purposes simultaneously. These sensors not only measure position for cross-track error calculation but also provide velocity, orientation, and terrain information. This multi-functionality reduces the need for additional specialized sensors, thereby limiting the increase in device complexity while improving measurement precision.

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

4Manufacturing precision

If velocity control adjustments are made frequently to reduce cross track error, then manufacturing precision improves, but loss of time increases due to continuous velocity changes

Engineering Contradiction:
Improvecross track error reductionVSAvoidtime lost to velocity adjustments
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system calculates predicted cross-track error based on current position, velocity, and guidance path information before the deviation occurs. By taking preliminary action to adjust velocity in anticipation of potential deviations, the system maintains precision without requiring continuous reactive adjustments, thereby reducing time loss while improving manufacturing precision.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4062730A1Speed control for reducing cross track error of implement-equipped machines
Publication Date: 2022.09.28 PTX TRIMBLE LLC
  • EP4062730A1 patent drawingFigure 1
  • EP4062730A1 patent drawingFigure 2
  • EP4062730A1 patent drawingFigure 3

AI summary

Described herein are systems, methods, and techniques for controlling a velocity of an implement-equipped machine (150). An actual position (122) of the implement-equipped machine is estimated based on sensor data captured using the machine's sensors (155). A cross track error (168) between a target position (129) and the actual position is calculated. An actual cross track error metric is calculated based on the cross track error. The actual cross track error metric is compared to a target cross track error metric to determine a velocity adjustment, where the velocity adjustment is determined so as to reduce a difference between the actual cross track error metric and the target cross track error metric. The velocity of the implement-equipped machine (150) is adjusted by the velocity adjustment.