Robot Base Return via Magnetic Field Search and Tracking
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Solution Overview
Problem
Existing self-propelling robots, such as lawn-mowing robots, face inefficiencies in returning to base stations due to complex navigation systems requiring multiple current loops, lengthy return times, limited directional flexibility, and high costs.
Innovation Solution
A simplified navigation system using a base station with a magnetic field generator that produces a converging magnetic field pattern, allowing robots to efficiently search and track lines of force to return to the base station, reducing energy consumption and implementation costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complex electronic navigational control system with multiple current loops is used, then navigation capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the complex outer loop conductor from the navigation system, retaining only the essential inner loop conductor at the base station. This simplification maintains the magnetic field generation capability needed for navigation while removing unnecessary complexity from the system architecture.
Solution Approach 2:
The patent uses a magnetic field as an information carrier that can be received and interpreted by the mobile robot. Instead of complex direct control connections, the system creates a magnetic field pattern that encodes navigation information, which the robot's receiver then decodes to determine position and guidance.
2Reliability
If traditional magnetic field navigation is used, then navigation capability is provided, but time to return to base station increases
Solution Approach 1:
The patent implements dynamic navigation by allowing the mobile robot to actively search for and track magnetic field lines in real-time. The system transitions from static field generation to dynamic field tracking, where the robot continuously adjusts its position to follow the magnetic field gradient toward the base station, significantly reducing return time.
Solution Approach 2:
The patent employs feedback mechanisms where the mobile robot's receiver continuously monitors the magnetic field strength and direction, and this information feeds back to the control system to adjust the robot's movement. This closed-loop control enables the robot to efficiently navigate back to the base station by constantly correcting its path based on magnetic field measurements.
3Reliability
If magnetic field navigation is used, then navigation is provided, but directional flexibility is limited to preferential directions
Solution Approach 1:
The patent creates an asymmetric magnetic field pattern where the field strength and direction vary in different spatial directions. This asymmetric field distribution provides the mobile robot with directional information from multiple angles, enabling it to navigate flexibly toward the base station from various starting positions and orientations, rather than being constrained to specific preferential directions.
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 solution significantly reduces the time and energy required for robots to return to base stations, increases reliability, and lowers implementation costs while allowing flexible directional return paths.
Implementation Method 1
a base station (80) positioned along the perimeter of the working area S; said base station (80) being such to generate a magnetic field (B) which extends at least in part over said working area S
Implementation Method 2
a magnetic field sensor (76) such to detect a set of lines of force of said magnetic field (B)
Data Source
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AI summary
It is described a working apparatus (100) for a limited working area (S). The apparatus comprises a base station (80) configured to generate a magnetic field (B) extending at least in part over the working area and comprises a self-propelling robot (1) having a normal operating mode wherein it performs a working cycle in the working area and a base return mode wherein it returns automatically to the base station. The self-propelling robot comprises means (20, 20a) for moving the self-propelling robot in the working area, as a function of a movement driving signal (S_amm), comprises a gyroscope (45) configured to generate an angular velocity signal (S_ω) indicating the measure of the angular velocity of the self-propelling robot around an axis substantially vertical with respect to the plane of the working area, comprises a magnetic field sensor (76) configured to generate a detection signal (S_ril) indicating a right or left position of the self-propelling robot with respect to a set of contiguous lines of force (91) of the magnetic field and comprises a processing unit (75) configured to control the movement of the self-propelling robot inside the working area. The processing unit comprises a magnetic field search module (75-4) configured, during a magnetic field search phase of the base return mode, to generate, as a function of the values of the detection signal and of a traveled distance signal (S_d) indicating the estimation of the distance traveled by the self-propelling robot, the movement driving signal for moving the self-propelling robot inside the working area to search for the set of contiguous lines of force (91) of the magnetic field inside the working area according to a defined search path (94). The processing unit further comprises a magnetic field tracking module (75-5) configured, during a magnetic field tracking phase of the base return mode subsequent to the magnetic field search phase, to generate, as a function of the values of the detection signal, of the angular velocity signal and of the traveled distance signal (S_d), the movement driving signal for moving the self-propelling robot inside the working area to track (91-1) at least a portion of the set of found contiguous lines of force by means of a plurality of maneuvers (92-2, 92-3) of crossing the set of found contiguous lines of force until reaching the base station.