Electrical Steering Assist for Materials Handling Vehicles

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Materials handling vehicles, such as walkie/rider pallet trucks, require significant steering force, especially at low speeds or when stationary, leading to operator fatigue and productivity issues due to the mechanical coupling of the steering arm to the steerable wheel.

Innovation Solution

An electrical steering assist system that includes a strain measuring assembly and a controller to detect the turning force applied by the operator and provide assistance to the steerable wheel, reducing the manual effort required for steering by using a steer drive unit controlled by the controller based on input from the strain measuring assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If mechanical coupling of steering arm to steerable wheel is used, then steering control is achieved, but steering force required becomes excessive at low speeds or when stationary

Engineering Contradiction:

Improvesteering easeVSAvoidsteering force required

Core Design Contradiction:

Ease of operationVSForce

Solution Approach 1:

The patent replaces the direct mechanical coupling system with an electrical steering assist system that uses sensors to detect steering intent and an electric motor to provide assistance torque, substituting pure mechanical force transmission with an electromechanical system that can amplify or assist the operator's input.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary steering assist mechanism between the steering arm and steerable wheel, consisting of a sensor to detect operator input and an electric motor to provide assistance, thereby mediating the force transmission and reducing the direct mechanical burden on the operator.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If higher steering force is required at stationary or low speeds, then steering control is maintained, but operator fatigue increases and productivity decreases

Engineering Contradiction:

Improvesteering controlVSAvoidoperator productivity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the operator's manual mechanical force with an electromechanical steering assist system that uses sensors to detect steering intent and an electric motor to provide the necessary torque, eliminating operator fatigue while maintaining steering control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The steering system provides self-service by automatically detecting the operator's steering intent through sensors and supplying the required assistance torque through the electric motor, eliminating the need for the operator to continuously exert high physical effort.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If mechanical coupling arrangement is used for steering arm to steerable wheel, then steering function is achieved, but steering force varies significantly with operating conditions

Engineering Contradiction:

Improvesteering adaptabilityVSAvoidsteering force variation

Core Design Contradiction:

Adaptability or versatilityVSForce

Solution Approach 1:

The patent implements a dynamic steering assist system that continuously monitors operating conditions through sensors and adjusts the electric motor's assistance torque in real-time, allowing the system to adapt to varying loads, speeds, and steering requirements rather than relying on fixed mechanical characteristics.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the steering force parameter dynamically by using sensor input to control the electric motor's output torque, allowing the steering assist to vary according to operating conditions such as vehicle speed, load weight, and steering angle, rather than maintaining a constant mechanical transmission ratio.

Inventive Principle:

Principle #35Parameter changes

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 system reduces the manual steering force needed, especially at low speeds or when stationary, thereby alleviating operator fatigue and improving productivity by providing mechanical assistance to the steering process.

Implementation Method 1

The input sensing device comprises a strain measuring assembly defining a strain sensitive region between the steering arm and the steer drive unit

Methodology Applied

Scientific EffectStrain measurement: Elasticity

Data Source

PatentUS9145163B2Electrical steering assist features for materials handling vehicles

Publication Date: 2015.09.29 CROWN EQUIP CORP

AI summary

A system for providing an electrical steering assist for a materials handling vehicle includes a drive housing; a steerable wheel coupled to the drive housing; a steering arm pivotally mounted to the drive housing; a steer drive unit coupled to the steerable wheel; an input sensing device; and a controller. The steering arm is operatively configured to determine a steering direction of the steerable wheel. The input sensing device is arranged to detect a turning force applied to the steering arm by an operator, wherein the turning force is provided to change the angle of travel of the vehicle. The input sensing device includes a strain measuring assembly defining a strain sensitive region between the steering arm and the steer drive unit. The controller is operatively configured to control the steer drive unit to turn the steerable wheel based upon a signal from the input sensing device.