Articulated Arm Control Unit for Precise End-Effector Positioning

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Solution Overview

Problem

Existing systems for automatically moving articulated arms, such as cranes, struggle to consistently achieve the same absolute position of the end-effector due to multiple possible configurations of the arm, making it difficult to reproduce manual movements accurately.

Innovation Solution

A system with a control unit connected to actuators and sensors that stores and reproduces the movements of an articulated arm by determining absolute coordinates of the end-effector and using predetermined logics to actuate the actuators, allowing for automatic re-performance of movements even with different arm configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If the system simply stores and repeats the movements performed during manual operation, then the automation extent is improved, but the manufacturing precision deteriorates because the end-effector cannot reach the same stored final position when the crane configuration differs

Engineering Contradiction:

Improveautomation of movement reproductionVSAvoidposition accuracy of end-effector

Core Design Contradiction:

Extent of automationVSManufacturing precision

Solution Approach 1:

The system continuously detects the current configuration of the articulated arm through sensors and uses this feedback information to dynamically adjust the actuator commands. The control unit compares the detected configuration with the stored reference configuration and calculates compensatory movements to ensure the end-effector reaches the intended target position, thereby maintaining high position accuracy during automated operation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the control parameters by storing not only the sequence of actuator movements but also the corresponding arm configuration parameters at each step. During reproduction, these stored parameter sets are retrieved and used to adjust the actuation sequence based on the actual current configuration, allowing the system to adapt to different starting configurations while maintaining precision.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the system stores the configuration of the articulated arm along with movement instructions, then the manufacturing precision is improved, but the device complexity increases

Engineering Contradiction:

Improveposition accuracy of end-effectorVSAvoidcomplexity of control system

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control unit is designed to perform multiple functions: it stores movement instructions, detects current configuration, calculates required adjustments, and generates corrected actuation commands. By making the control unit multi-functional, the system avoids adding separate dedicated devices for each function, thereby managing complexity while achieving high position accuracy through comprehensive control.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system merges the storage of movement instructions and configuration parameters into a single integrated data structure, and combines the detection, calculation, and actuation control functions into one unified control unit. This merging reduces the number of separate components and interfaces, managing device complexity while maintaining the precision benefits of configuration-aware control.

Inventive Principle:

Principle #5Merging (Combining)

3Manufacturing precision

If the system detects and compensates for configuration differences, then the position accuracy is improved, but the loss of time increases due to additional detection and calculation steps

Engineering Contradiction:

Improveposition accuracy of end-effectorVSAvoidtime for movement reproduction

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs preliminary detection of the current arm configuration before executing the movement sequence. By detecting the configuration in advance and pre-calculating the required compensatory adjustments, the system avoids time-consuming corrections during the actual movement execution, thereby minimizing time loss while maintaining high position accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The detection of arm configuration and the execution of corrective movements are integrated into a continuous control process rather than being separate discrete steps. The control unit continuously monitors configuration during movement and applies real-time corrections, ensuring that the useful action of moving the end-effector to the target position continues without interruption or significant time loss.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentEP3556709B1System for automatically moving an articulated arm, particularly of a loading crane

Publication Date: 2020.03.25 FASSI GRU

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AI summary

The present invention refers to a system for automatically moving an articulated arm (101). The system comprises a plurality of sensors associated to the bodies of the articulated arm, adapted to enable to determine the absolute coordinates of the end-effector (105), and a control unit configured to perform a step of storing a movement of the end-effector (105) and a step of automatically re-performing the stored movement of the end-effector (105). During the storing step, in a plurality of sampling instants, the absolute coordinates of the end-effector (105) and the actuators used for moving the end-effector (105) between two following absolute coordinates, are stored.