Robotic Lawnmower Dual-Mode Navigation for GNSS Signal Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robotic lawnmowers face challenges in navigating heterogeneous and compact work areas due to signal blockages and interference, leading to frequent stops, increased wear, power consumption, and potential malfunctions when using satellite navigation systems, which can result in incomplete grass cutting and premature equipment failure.
Innovation Solution
Implementing a deduced reckoning navigation system combined with landmark scanning to allow continuous operation and rapid recalibration of satellite signals, reducing the need for prolonged stops and improving navigation accuracy by defining a search space based on landmark positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If satellite navigation is used for navigation, then navigation accuracy is improved, but reliability deteriorates due to signal blockages from obstacles
Solution Approach 1:
The patent combines satellite navigation with deduced reckoning navigation to create a hybrid navigation system. When satellite signals are blocked, the system seamlessly transitions to deduced reckoning navigation using wheel encoders and inertial sensors, ensuring continuous and reliable operation without complete loss of navigation capability
Solution Approach 2:
The patent introduces landmarks as intermediary reference points that the robotic lawnmower can detect and use for position verification. These landmarks serve as backup reference points when satellite signals are unavailable, providing an intermediate navigation method that bridges the gap between satellite and deduced reckoning navigation
2Reliability
If the robotic lawnmower stops to wait for satellite signal recovery, then navigation reliability is improved, but productivity deteriorates due to repeated stops
Solution Approach 1:
The patent implements continuous navigation operation by combining multiple navigation methods. The robotic lawnmower never completely stops navigation functionality - when satellite signals are blocked, it immediately switches to deduced reckoning navigation, maintaining continuous position estimation and enabling uninterrupted grass cutting operations
Solution Approach 2:
The patent creates a dynamic navigation system that can switch between different navigation modes based on signal availability. The system adaptively transitions between satellite navigation, deduced reckoning navigation, and landmark-based verification, optimizing performance for current conditions without requiring complete stops
3Reliability
If frequent stops occur for signal recovery, then navigation reliability is improved, but wear and power consumption worsen
Solution Approach 1:
The patent eliminates the need for complete stops by maintaining continuous navigation through deduced reckoning methods. The robotic lawnmower keeps moving and cutting grass while simultaneously performing position estimation using wheel encoders and inertial sensors, avoiding energy-wasting stop-start cycles
4Measurement precision
If satellite navigation is used, then navigation accuracy is improved, but device complexity worsens due to additional navigation systems
Solution Approach 1:
The patent makes the robotic lawnmower's navigation system multi-functional by integrating satellite navigation, deduced reckoning navigation, and landmark detection capabilities into a single unified system. This universal navigation system can operate in multiple modes depending on environmental conditions, reducing the need for separate dedicated systems for each navigation method
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A robotic lawnmower (100) for movable operation within a work area (205) has a satellite navigation device (190), a landmark scanner (193) and a controller (110). The controller causes the robotic lawnmower (100) to movably operate within the work area (205) in a first operating mode, the first operating mode being based on positions determined from satellite signals received by the satellite navigation device (190). The controller determines that a position cannot be reliably determined based on satellite signals received by the satellite navigation device (190), and in response thereto causes the robotic lawnmower (100) to movably operate within the work area (205) in a second operating mode. In the second operating mode, the controller receives scanning information from said landmark scanner (193) and identifies at least one landmark based on the received scanning information and determines a landmark-based position estimate. The controller defines a search space using the landmark-based position estimate, and the satellite navigation device (190) is reconstructed based on the defined search space. Once the satellite navigation device (190) has been reconstructed, the controller causes the robotic lawnmower (100) to again operate in the first operating mode.