Operator Platform Presence Sensing to Prevent Dumper Drive-Off
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Solution Overview
Problem
Existing walk-behind dumper vehicles lack a reliable mechanism to ensure the operator is present on the platform before allowing movement, leading to accidental operation when the platform is deployed without an operator, or when small items fall on it.
Innovation Solution
A working machine with a sensor arrangement that detects an external force on the operator platform when it is in the deployed position, preventing movement of the ground engaging propulsion system unless an operator is standing on the platform, and featuring a biasing element and various sensor types (proximity, limit switch, magnetic field, and contact sensors) to determine the operator's presence and prevent accidental movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the operator platform is deployed without an operator presence detection system, then the machine can be operated in walk-behind mode with platform deployed, but accidental operation may occur when small items or debris fall on the platform
Solution Approach 1:
The sensor arrangement detects operator presence before the machine is allowed to move. The system checks whether an operator is standing on the platform prior to enabling propulsion, preventing accidental operation before it can occur.
Solution Approach 2:
A sensor arrangement acts as an intermediary between the operator platform and the propulsion system. The sensor detects external forces on the platform and transmits this information to the control system, which then decides whether to allow movement based on the detected presence.
2Reliability
If a sensor arrangement is added to detect operator presence, then accidental operation is prevented, but the device complexity increases
Solution Approach 1:
The operator presence detection function is extracted as a separate sensor arrangement independent from the main propulsion control system. This modular approach allows the safety function to be added without fundamentally redesigning the entire control system.
Solution Approach 2:
The patent replaces complex mechanical interlocking systems with sensor-based detection. Instead of using mechanical switches or complex linkages to detect operator presence, force sensors or weight sensors electronically detect the operator's weight on the platform.
3Ease of operation
If the machine allows movement when platform is in intermediate position, then operational flexibility is improved, but safety is compromised due to unstable platform position
Solution Approach 1:
The control system checks the platform position before allowing movement. It ensures the platform is in a stable deployed position or fully stowed position before enabling the propulsion system, preventing operation during intermediate unstable states.
Solution Approach 2:
The sensor arrangement continuously monitors platform position and provides feedback to the control system. The system only permits movement when feedback confirms the platform is in a safe, stable position, automatically preventing operation during intermediate transitions.
Data Source
AI summary
A working machine has a frame, a ground engaging propulsion system, a drive arrangement for providing motive power to the ground engaging propulsion system, an operator platform pivotally connected to the frame and moveable between a deployed position for supporting an operator thereon and a stowed position; and a sensor arrangement configured to sense when an external force is applied to the operator platform when said operator platform is in the deployed position. The machine prevents movement of the ground engaging propulsion system when the sensor arrangement does not sense an external force applied to the operator platform when said operator platform is in the deployed position.