Forklift Surroundings Sensing for Predictive Speed Limiting

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Solution Overview

Problem

Conventional industrial trucks face challenges in effectively avoiding collisions with obstacles that are not directly in their monitoring area but are close by, leading to potential collisions, and existing collision avoidance systems cause unnecessary speed reductions and driver dissatisfaction due to false alarms.

Innovation Solution

A forklift truck equipped with environmental sensing sensors and a control system that monitors both critical and semi-critical areas around the truck, determining predicted travel corridors and adjusting speed limits based on the distance and angle of obstacles to ensure effective collision avoidance without undue operational interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the monitoring area is expanded to detect obstacles outside the critical area, then collision avoidance capability is improved, but false alarms increase and driver acceptance decreases

Engineering Contradiction:
Improvecollision avoidance capabilityVSAvoiddriver acceptance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system divides the monitoring area into two distinct zones with different functions: a critical monitoring area that triggers speed limitation only when obstacles are detected, and a semi-critical monitoring area that triggers speed limitation only when obstacles are detected combined with specific driving conditions (steering angle and speed thresholds). This local differentiation allows the system to expand monitoring coverage while maintaining driver acceptance by reducing false alarms in areas where obstacles pose minimal risk.

Inventive Principle:
Principle #3Local quality

2Reliability

If the monitoring area is expanded to detect obstacles outside the critical area, then collision avoidance capability is improved, but unnecessary speed reductions occur and throughput decreases

Engineering Contradiction:
Improvecollision avoidance capabilityVSAvoidthroughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Different monitoring zones are implemented with differentiated response strategies. The critical monitoring area applies speed limitation immediately upon obstacle detection, while the semi-critical monitoring area applies speed limitation only when combined with specific driving conditions (steering angle and speed thresholds). This allows the system to expand monitoring coverage while maintaining productivity by avoiding unnecessary speed reductions in low-risk areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts the monitoring and response strategy based on real-time driving conditions. When the forklift is moving at low speed with small steering angles in the semi-critical area, speed limitation is activated to prevent collisions. When driving conditions change (higher speed or larger steering angles), the system adjusts its response to maintain throughput while still ensuring safety. This dynamic adaptation resolves the contradiction between safety and productivity.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If environmental sensing sensors are used to monitor a large area behind the forklift, then obstacle detection capability is improved, but unnecessary warnings are triggered and driver attention is reduced

Engineering Contradiction:
Improveobstacle detection capabilityVSAvoiddriver attention
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The system implements different warning strategies for different monitoring zones. In the critical monitoring area, speed limitation is triggered immediately upon obstacle detection. In the semi-critical monitoring area, speed limitation is triggered only when obstacles are detected combined with specific driving conditions (steering angle and speed thresholds). This local differentiation improves obstacle detection capability while reducing unnecessary warnings that would otherwise reduce driver attention.

Inventive Principle:
Principle #3Local quality

4Adaptability or versatility

If the forklift uses large steering angles to achieve small turning radius, then maneuverability is improved, but the rear of the truck swings out sharply increasing collision risk

Engineering Contradiction:
ImprovemaneuverabilityVSAvoidcollision risk
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary assessment of collision risk by monitoring steering angle and combining it with environmental sensing data before the forklift actually swings into potentially hazardous positions. When large steering angles are detected combined with obstacles in the semi-critical monitoring area, speed limitation is activated in advance to prevent the rear of the truck from swinging out into obstacles. This preliminary action maintains maneuverability while preventing collisions.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4674802A1Industrial truck with a surroundings detection sensor
Publication Date: 2026.01.07 LINDE MATERIAL HANDLING GMBH
  • EP4674802A1 patent drawingFigure 1
  • EP4674802A1 patent drawingFigure 2
  • EP4674802A1 patent drawingFigure 3

AI summary

The present invention relates to a forklift truck (1) comprising a steering mechanism (4) for steering the forklift truck (1), a drive mechanism (5) for moving the forklift truck (1), at least one environmental sensing sensor (7), and a control unit (6) which is connected to the at least one environmental sensing sensor (7), the steering mechanism (4), and the drive mechanism (5). The environmental sensing sensor (7) is configured to monitor the area (9) surrounding the forklift truck (1) for obstacles (10).The controller (6) is configured to activate the environment detection sensor (7) to detect at least one obstacle (10) in a critical monitoring area (15) and/or a semi-critical monitoring area (16) of the environment (9) of the industrial truck (1), wherein the critical monitoring area (15) is limited by a critical area boundary (15-1), and wherein the semi-critical monitoring area (16) is arranged outside the critical monitoring area (15) and adjacent to the critical monitoring area (15) on the outside.The control unit (6) is designed to determine, depending on a steering angle of the industrial truck (1) set by the steering unit (4), a predicted travel corridor (12) of the moving industrial truck (1) within the critical monitoring area (15) and, for at least one future point in time of the travel movement of the industrial truck (1), to determine a predicted position (17) of the industrial truck (1) in the predicted travel corridor (12) and to determine a clearance distance (18) between the predicted position (17) of the industrial truck (1) and the position of an obstacle (10) detected by the environment sensor (7) in the semi-critical monitoring area (16).The control system (6) is further designed to determine a travel distance (19) between the predicted position (17) of the industrial truck (1) and a current position (20) of the industrial truck (1) and to control the drive system (5) to limit the travel speed of the industrial truck (1) depending on the determined travel distance (19) and depending on the determined passing distance (18).