This article introduces passive wheels as the new localization system for automated guided vehicles (AGVs). The article focuses on investigating the accuracy of the proposed system and comparing with other widely used solutions: rotary encoders coupled with drive wheels, AHRS and LiDAR scanner. The fusion of dead reckoning and inertial data is acquired by the implementation of the Kalman filter. On the other hand, the fusion of LiDAR data depends on application of the AMCL or the graph-based algorithm. The study was conducted on five different scenarios, designed to investigate the influence of specific types of movements on the performance of tested localization methods. Results indicate, that passive wheels dead reckoning outperforms drive wheels dead reckoning in most scenarios, minimizing errors due to reduced both longitudal and lateral slippages, which appear during AGV accelerating, decelerating and turning. AHRS integration improves accuracy, especially in scenarios involving significant amount of angular motion. LiDAR-based methods in short term show mediocre results, due to relatively high, but steady values of error. The study highlights the importance of the map's quality for LiDAR-based techniques and points up the conditions, under which the LiDAR-based techniques do not operate very well. In conclusion, the research provides insights into the strengths and weaknesses of various AGV localization techniques in various movement scenarios, emphasizing the impact of sensor choice and path-shape conditions on accuracy.

This study demonstrates a new method for quantifying thread engagement in mechanical connections and verifies its applicability using biomedical implants under push-out tests. The focus is on orthopedic plate implants employed for bone fracture fixation, which, by design, allow off-axis screw insertion to accommodate different contact conditions. Thread engagement is crucial in determining connection strength and stability. In medical practice, off-axis screw placement is usually necessary due to bone geometries and implant plate rigidity. To address this, the study proposes a quantification method using non-destructive testing with X-ray micro-computed tomography and automated image processing, although tuning the image processing parameters is vital for accurate and reliable results. This enables detailed 3D models of screw-plate interfaces for precise thread engagement measurement. The results show that thread engagement decreases with both, increased off-axis insertion angles and higher torque during insertion. Correlation analysis reveals a strong relationship (R² > 0.6) between average thread engagement and push-out strength, underscoring the importance of proper screw placement for stable fixation.

The paper presents the design and testing of a new servo drive for turning non-circular shapes. The presented solution is based on a commercially available piezoelectric drive unit with a stroke equal to 1000 µm and a resonant frequency of 150 Hz. The device was used in a conventional turning lathe and installed in a tool turret. The performance of the proposed tool was tested while turning multiple non-circular contours from a cylindrical shaft made of 6082 aluminum alloy. The machining accuracy was tested online using a laser sensor and offline with a coordinate measuring machine. The additional aim of those tests was also to verify if the application of an online transducer can allow a confident preliminary assessment of as-machined geometry. The drive positioning accuracy was compensated using 6th order polynomial what resulted in the fabrication of non-circular contours with an accuracy of no less than 39.8 µm when operating below the limit frequency of the drive (<9 Hz). It was found out that the deviations of the profile from ideal geometries increase linearly with frequency when turning at higher than the limit frequency.

Data set for article "Application of piezoelectric fast tool servo for turning non-circular shapes made of 6082 aluminum alloy" in Applied Sciences

Repeated use can alter the geometry and functional performance of orthopedic drill bits, yet geometry, process load, and hole dimensions are rarely tracked together. Four integrated commercial drill types—Stryker (3.2 and 3.5 mm), Synthes (4.5 mm), and Zimmer (4.3 mm)—produced successive through-holes in a 6 mm short-glass-fiber-filled epoxy cortical-bone analog at 900 rpm and approximately 40 mm/min. Projected point angle was measured intermittently, maximum thrust force and axial feed work were calculated per hole, and entrance diameter was measured optically. The primary estimand was longitudinal change within each drill type; the design was not factorial, and differences among types cannot be attributed separately to manufacturer, diameter, geometry, intended function, or alloy. Drill-type-specific models included fixed specimen intercepts. Force, work, and diameter were described using constrained monotonic functions selected by AICc, while trend inference used permutation-based Spearman tests. Point angle decreased significantly only for the Stryker drills. Force and work increased in every type, whereas entrance diameter decreased significantly for Stryker 3.5 mm, Synthes, and Zimmer. Pairwise force/work–diameter associations did not remain significant after adjustment for hole number and multiplicity. Repeated-use exposure therefore produced drill-type-specific mechanical and dimensional drift, but the study did not directly quantify cutting-edge wear or establish a causal material mechanism.