Offset-Blade Floor Saw Yaw Control Using Drive Wheel Torque
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Solution Overview
Problem
Floor saws with offset cutting blades experience drifting issues due to imbalance, requiring manual compensation by operators, which is inefficient and strains the operator, and existing compensation methods are not always effective.
Innovation Solution
A floor saw with a control unit that adjusts the torque and speed of drive wheels and incorporates sensors like IMUs and vision-based sensors to automatically compensate for drift, allowing for continuous and precise control of yaw motion, and includes features like wheel braking and weight redistribution for stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the cutting blade is mounted offset to one side of the floor saw, then cuts can be made close to walls or obstacles, but the saw experiences imbalance and drifting towards the blade side
Solution Approach 1:
The patent changes the operational parameters of the drive wheels by varying their rotational speeds dynamically. The control unit adjusts the speed of each drive wheel independently based on detected drift conditions, allowing the saw to compensate for the imbalance caused by offset blade mounting without requiring physical reconfiguration.
2Reliability
If fixed gear ratios are used on drive wheels to compensate for drift, then some drift compensation is achieved, but the compensation is seldom perfect and residual drift remains
Solution Approach 1:
The patent replaces the mechanical gear ratio adjustment system with an electronic control system that uses sensors to detect yaw motion and a control unit to dynamically adjust drive wheel speeds. This substitution allows for continuous, precise compensation rather than fixed mechanical ratios, eliminating residual drift while maintaining simplicity.
3Reliability
If the entire driven axle is steered to compensate for drift, then drift compensation is achieved, but the system becomes more complex and manual adjustment is required
Solution Approach 1:
The patent implements self-service drift compensation through an automated system where sensors continuously monitor the saw's yaw motion and the control unit automatically adjusts drive wheel speeds to maintain straight-line cutting. This eliminates the need for manual axle steering adjustments by the operator, reducing physical effort while maintaining effective drift compensation.
4Reliability
If manual compensation by operator body weight is used, then residual drift can be compensated, but the operation becomes more difficult and places additional strain on the operator
Solution Approach 1:
The patent replaces manual body-weight compensation with an electronic control system that uses sensors to detect drift and automatically adjusts drive wheel speeds. This substitution transfers the compensation function from the operator's physical effort to an automated mechanical-electronic system, eliminating operator strain while maintaining effective drift compensation.
5Reliability
If sensor arrangements and control systems are added for automatic drift compensation, then drift compensation effectiveness is improved, but device complexity increases
Solution Approach 1:
The patent implements a feedback control system where sensors detect the saw's actual yaw motion and feed this information back to the control unit, which then adjusts drive wheel speeds accordingly. This closed-loop feedback mechanism provides automatic, continuous drift compensation with minimal added complexity, as the system self-regulates based on real-time conditions.
Data Source
AI summary
A floor saw for sawing in a concrete surface segment (160), the floor saw comprising a circular cutting blade (110) arranged transversally offset from a centrum line (C), which centrum line (C) is aligned with a forward direction (F) of the floor saw, the floor saw further comprising at least two supporting wheels (120) arranged to support the floor saw on the concrete surface segment (160), out of which supporting wheels at least one is a drive wheel, a sensor arrangement (140) configured to determine a current yaw motion of the floor saw, and a control unit (130) configured to obtain a desired yaw motion setting, wherein the drive wheel is arranged on an opposite side of the centrum line (C) compared to the circular cutting blade (110) and arranged to generate a respective variable wheel force by a respective first electric machine controlled by the control unit (130), and wherein the control unit (130) is arranged to control the first electric machine to reduce a difference between the current yaw motion of the floor saw and the desired yaw motion setting.