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Kan Yoneda - One of the best experts on this subject based on the ideXlab platform.
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Feedforward and Feedback Dynamic Trot Gait Control for Quadruped Walking Vehicle
Autonomous Robots, 2002Co-Authors: Ryo Kurazume, Kan Yoneda, Shigeo HiroseAbstract:To realize dynamically stable walking for a quadruped walking robot, the combination of the trajectory planning of the body and leg position (feedforward control) and the adaptive control using sensory information (feedback control) is indispensable. In this paper, we propose a new body trajectory, the 3D sway compensation trajectory, for a stable trot gait; we show that this trajectory has a lower energy consumption than the conventional sway trajectory that we have proposed. Then, for the adaptive attitude control method during the 2-leg supporting phase, we consider four methods, that is, a) rotation of body along the diagonal Line between supporting feet, b) translation of body along the Perpendicular Line between supporting feet, c) vertical swing motion of recovering legs, and d) horizontal swing motion of recovering legs; we then describe how we verify the stabilization efficiency of each method through computer simulation, stabilization experimentation, and experimenting in walking on rough terrain using the quadruped walking robot, TITAN-VIII.
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feedforward and feedback dynamic trot gait control for a quadruped walking vehicle
International Conference on Robotics and Automation, 2001Co-Authors: Ryo Kurazume, Shigeo Hirose, Kan YonedaAbstract:We propose a new trajectory planning for the stable trot gait, named 3D sway compensation trajectory, and show that this trajectory has lower energy consumption than the conventional sway trajectory proposed previously by Yoneda et al. (1995). As the adaptive attitude control method was used during the 2-leg supporting phase of the trot gait, we consider four methods: 1) rotation of body along the diagonal Line between supporting feet; 2) translation of body along the Perpendicular Line between supporting feet; 3) vertical swing motion of recovering legs; and 4) horizontal swing motion of recovering legs. The stabilization efficiency of each method was verified through computer simulation and the damping experiment using a quadruped walking robot, TITAN-VIII. Furthermore, the dynamic trot gait control that combines the feedforward control based on the proposed 3D sway compensation trajectory and the adaptive feedback control using body translation and vertical motion of swing legs was developed, and the walking experiment on rough terrain using TITAN-VIII was carried out.
Shigeo Hirose - One of the best experts on this subject based on the ideXlab platform.
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Feedforward and Feedback Dynamic Trot Gait Control for Quadruped Walking Vehicle
Autonomous Robots, 2002Co-Authors: Ryo Kurazume, Kan Yoneda, Shigeo HiroseAbstract:To realize dynamically stable walking for a quadruped walking robot, the combination of the trajectory planning of the body and leg position (feedforward control) and the adaptive control using sensory information (feedback control) is indispensable. In this paper, we propose a new body trajectory, the 3D sway compensation trajectory, for a stable trot gait; we show that this trajectory has a lower energy consumption than the conventional sway trajectory that we have proposed. Then, for the adaptive attitude control method during the 2-leg supporting phase, we consider four methods, that is, a) rotation of body along the diagonal Line between supporting feet, b) translation of body along the Perpendicular Line between supporting feet, c) vertical swing motion of recovering legs, and d) horizontal swing motion of recovering legs; we then describe how we verify the stabilization efficiency of each method through computer simulation, stabilization experimentation, and experimenting in walking on rough terrain using the quadruped walking robot, TITAN-VIII.
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feedforward and feedback dynamic trot gait control for a quadruped walking vehicle
International Conference on Robotics and Automation, 2001Co-Authors: Ryo Kurazume, Shigeo Hirose, Kan YonedaAbstract:We propose a new trajectory planning for the stable trot gait, named 3D sway compensation trajectory, and show that this trajectory has lower energy consumption than the conventional sway trajectory proposed previously by Yoneda et al. (1995). As the adaptive attitude control method was used during the 2-leg supporting phase of the trot gait, we consider four methods: 1) rotation of body along the diagonal Line between supporting feet; 2) translation of body along the Perpendicular Line between supporting feet; 3) vertical swing motion of recovering legs; and 4) horizontal swing motion of recovering legs. The stabilization efficiency of each method was verified through computer simulation and the damping experiment using a quadruped walking robot, TITAN-VIII. Furthermore, the dynamic trot gait control that combines the feedforward control based on the proposed 3D sway compensation trajectory and the adaptive feedback control using body translation and vertical motion of swing legs was developed, and the walking experiment on rough terrain using TITAN-VIII was carried out.
Ryo Kurazume - One of the best experts on this subject based on the ideXlab platform.
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Feedforward and Feedback Dynamic Trot Gait Control for Quadruped Walking Vehicle
Autonomous Robots, 2002Co-Authors: Ryo Kurazume, Kan Yoneda, Shigeo HiroseAbstract:To realize dynamically stable walking for a quadruped walking robot, the combination of the trajectory planning of the body and leg position (feedforward control) and the adaptive control using sensory information (feedback control) is indispensable. In this paper, we propose a new body trajectory, the 3D sway compensation trajectory, for a stable trot gait; we show that this trajectory has a lower energy consumption than the conventional sway trajectory that we have proposed. Then, for the adaptive attitude control method during the 2-leg supporting phase, we consider four methods, that is, a) rotation of body along the diagonal Line between supporting feet, b) translation of body along the Perpendicular Line between supporting feet, c) vertical swing motion of recovering legs, and d) horizontal swing motion of recovering legs; we then describe how we verify the stabilization efficiency of each method through computer simulation, stabilization experimentation, and experimenting in walking on rough terrain using the quadruped walking robot, TITAN-VIII.
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feedforward and feedback dynamic trot gait control for a quadruped walking vehicle
International Conference on Robotics and Automation, 2001Co-Authors: Ryo Kurazume, Shigeo Hirose, Kan YonedaAbstract:We propose a new trajectory planning for the stable trot gait, named 3D sway compensation trajectory, and show that this trajectory has lower energy consumption than the conventional sway trajectory proposed previously by Yoneda et al. (1995). As the adaptive attitude control method was used during the 2-leg supporting phase of the trot gait, we consider four methods: 1) rotation of body along the diagonal Line between supporting feet; 2) translation of body along the Perpendicular Line between supporting feet; 3) vertical swing motion of recovering legs; and 4) horizontal swing motion of recovering legs. The stabilization efficiency of each method was verified through computer simulation and the damping experiment using a quadruped walking robot, TITAN-VIII. Furthermore, the dynamic trot gait control that combines the feedforward control based on the proposed 3D sway compensation trajectory and the adaptive feedback control using body translation and vertical motion of swing legs was developed, and the walking experiment on rough terrain using TITAN-VIII was carried out.
Hom-lay Wang - One of the best experts on this subject based on the ideXlab platform.
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Maxillary Sinus Lateral Wall Thickness and Their Morphologic Patterns in the Atrophic Posterior Maxilla
2020Co-Authors: Alberto Monje, D D S, Phd Andrés Catena, Md Florencio Monje, Md Raúl Gonzalez-garcía, Pablo Galindo-moreno, Phd D D S, Fernando Suarez, D D S *, Hom-lay WangAbstract:Purpose: The aim of the present study was to examine the sinus lateral wall thickness of atrophic posterior maxilla (< 10 mm) of complete and partial edentulous patients and determine the influence of the residual ridge height (RH), gender and age upon maxillary lateral wall thickness (LWT). Material and methods: Four hundred fourteen measures were taken from 140 consecutive patients that met the inclusion criteria. On the selected sagittal section, a built-in digital caliper recorded in millimeters the following measurements: residual ridge and lateral wall thickness [a Perpendicular Line at 3, 5, 7, 10, 13 and 15 mm from the lowest point of the sinus floor]. The edentulous spans were further classified as complete edentulous atrophic maxilla (CEM) and partial edentulous atrophic maxilla (PEM). The mixed Linear model was used to test the effects of "gender", "type of edentulism", "edentulous span", and "residual height" on the measurement of the LWT of the sinus Results: Mean LWT for PEM was 1.71 ± 0.12 mm, while for CEM was 1.57 ± 0.07 mm (p=0.01). The mixed model yielded significant effect of "edentulous span" (p=0.048), and the interactions between "type of edentulism" and "edentulous span" (p<0.001), and "edentulous span" by RH (p<0.01). "Age" and RH were positively associated to LWT, however they do not interact with RH, "gender" or "type of edentulism". RH has been shown to correlate with "edentulous span" (p<0.001) and "type of edentulism" (p=0.01). The longer the "edentulous span", the thinner the LWT. Similarly, RH was larger for PEM (6.85, SE=0.34) than CEM (5.69, SE=0.26). Conclusions: The maxillary sinus lateral wall tends to increase in thickness from the second premolar to the second molar; and from 5mm up to 15 mm. In addition, residual ridge height, presence of teeth adjacent to the edentulous atrophic ridge, and age have all been shown to influence maxillary sinus lateral wall thickness. KEY WORDS (MESH 2013): Maxillary sinus, maxillary sinus floor augmentation, Morphology, Maxillofacial procedures, Bone regeneration Oral rehabilitation in the posterior maxilla often presents a challenge to the clinician due to ridge resorption after tooth extraction and subsequent sinus pneumatization. 1, 2 Several techniques have been used to overcome this challenge: bone augmentation, 3 short implants 4 or tilted implants; 5, 6 however, shorter and tilted implants may not have long-term stability due to strong occlusal forces exerted in this area. 10 Two main approaches for sinus augmentation have been proposed: lateral window approach 11 and crestal approach using primarily osteotomies. 12 Both have shown acceptable results; 10 however, the lateral window approach is still considered more predictable in terms of outcomes and safety, especially for cases with minimal bone height. 13 Despite this predictability, complications do occur, most related to sinus anatomy. 14 Extensive bleeding, implant migration and sinus infection should be considered when performing sinus augmentation. Hence, clinicians should learn how to prevent and manage these problems. 14 The presence of septum, sinus shape/morphology, and a sharp angulation between the lateral and medial wall have all been shown to increase the chance of membrane perforation and indirectly leads to sinus complications 17 Hence, knowledge of the sinus anatomy, including lateral wall thickness, is key to minimize these potential complications. Cone-beam computed tomography (CBCT) offers a 3-dimensional reliable diagnostic image for detecting anatomical variations of the maxillofacial region and enables us to report more precise data. Presently, only two studies have evaluated sinus lateral wall thickness by radiographic assessment, MATERIALS AND METHODS This research study used a retrospective clinical database that included patients who were previously treated as part of routine periodontal care using accepted therapy for each patient's specific clinical needs. Since the current research involved a retrospective analysis of pre-existing data and current data do not include any identifiable private information, this research did not require approval by an institutional ethics board. Patient Selection Overall, 414 measures were taken from 140 consecutive Caucasians patients fulfilling the inclusion criteria, of which 270 were female and 144 were males (2:1 female: male ratio) with a mean age of 67.2 ± 18.8 years. Image Acquisition The scans used in the present study were selected from the CBCT database. All images were obtained with a CBCT machine ‡ ‡ ‡ in the Center of Implantology, Oral and Maxillofacial Surgery (CICOM), Badajoz, Spain by an experience radiologist (VC) between 2010 and 2013. The imaging parameters were set at 120kVp, 18.66mAs, scan time 20 seconds, resolution 0.4 mm, and a field of view (FOV) which varied based on the scanned region. The CBCT scans of each individual were transferred to a desktop computer equipped with an implant planning software program § § § .Data were saved in the Digital Imaging and Communications in Medicine (DICOM) format. Inclusion and Exclusion Criteria One examiner (AM) conducted the image screening using the following inclusion/exclusion criteria. -Images were included if: 1. Maxillary sinuses located between premolars and molars as a result of missing single or multiple teeth 2. The residual ridge height (RH) was < 10 mm. 3. Presence of teeth adjacent to or opposing the edentulous area so the location of the edentulous ridges corresponding to the tooth site could be identified 4. The maxillary sinus to be measured was visible from its floor to at least 15 mm from the alveolar crest of the edentulous ridge. -Images were excluded if: 1. Images were unclear or incomplete due to scattering or other reasons 2. Edentulous ridge height was more than 10 mm 3. The location of the edentulous ridge cannot be determined 4. Presence of sinus pathology that made the measurement impossible 5. The outLine of the edentulous ridge cannot be identified, e.g. extraction sockets 6. The sinus had been grafted or in which implants had been placed Image Analysis On the selected sagittal section, a built-in digital caliper made the following measurements in millimeters: residual ridge height (RH) [the distance from the alveolar crest up to the lowest point of the sinus floor] and lateral wall thickness (LWT) [a Perpendicular Line at 3, 5, 7, 10, 13 and 15 mm from the lowest point of the sinus floor] Statistic Analysis The mixed Linear model as implemented in SPSS v17.0 was used to test the effects of "gender", "type of edentulism", "edentulous span" (within patients: 1M, 2M, 2PM), and RH of the measurement (within patients: 3, 5, 7, 10, 13 and 15 mm) on the LWT of the sinus. The RH and patient age served as covariates for the analysis. The mixed model was also used to test the effects of "gender", " type of edentulism", and "edentulous span" on RH, with patient age serving as a covariate. The type of covariance matrix was selected using the Schwarz Bayesian criterion. A p-level of 0.05 was setup for significance level. When needed, the Sidak correction for post-hoc comparison was used. RESULTS The average thickness in millimeters (mm) and the 95% confidence intervals for the LWT as a function of edentulous span and height of the measurement are presented in Using a compound symmetry covariance matrix, the mixed model yielded main effect of "edentulous span" Regarding the influence of RH upon LWT, the mixed model yielded only main effect of "type of edentulous", F (1,141)=6.82, p=0.01, and "edentulous span", F (2,213)=9.56, p<0.001. RH was larger for PEM (6.85, SE=0.34) than CEM (5.69, SE=0.26). In addition, RH was found to be smaller for 1M and 2M (5.96, SE=0.23, 5.89, SE=0.30) than for 2PM (6.96, SE=0.27) edentulous spans. DISCUSSION Maxillary sinus augmentation via lateral approach presents complexity for dissection and elevation of sinus membrane, often due to the irregular anatomy associated with the sinus. The management of the lateral wall during sinus augmentation via lateral approach has been emphasized due to the fact that its thickness may influence the integrity of the Schneiderian membrane. 24 On the other hand, Neiva et al. showed, in Caucasian skulls, that mean LWT was thinner than the one found in the present study (0.91 ± 0.43 mm). Again, instruments used to record the data might be the cause of this disparaty. Regarding the vertical height where LWT were measured, significant differences were found at 10 mm from the sinus floor of the edentulous region between the first molar and second premolar and between the second molar and second premolar, as well as at 15 mm between the first and second molar. Our results showed similarities to previous studies In addition, previous studies have assessed the influence of gender and age on the maxillary sinus anatomy; Results from our study implies that the less RH, the thinner the lateral maxillary sinus wall. As reported by Monje et al. who showed that bone density in maxillary sinus region is influenced by the remaining bone height, a thinner LWT suggests a lower bone 5 Journal of Periodontology; Copyright 2013 DOI: 10.1902/jop.2013 density CONCLUSION The maxillary sinus lateral wall tends to increase in thickness from the second premolar to the second molar and from 5mm up to 15 mm. In addition, residual ridge height, presence of teeth to adjacent the edentulous atrophic ridge, and age all have been shown to influence maxillary sinus lateral wall thickness. Nonetheless, each case must be individualized in order to foresee possible complications due to the anatomic variations. ACKNOWLEDGEMENT
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maxillary sinus lateral wall thickness and morphologic patterns in the atrophic posterior maxilla
Journal of Periodontology, 2014Co-Authors: Alberto Monje, Fernando Suarez, Andres Catena, Florencio Monje, Raul Gonzalezgarcia, Pablo Galindomoreno, Hom-lay WangAbstract:Background: The aim of the present study is to examine the sinus lateral wall thickness (LWT) of atrophic posterior maxilla (<10 mm) of patients with complete and partial edentulism and determine the influence of residual ridge height (RH), sex, and age on maxillary LWT.Methods: Four hundred fourteen measures were taken from 140 consecutive patients that met the inclusion criteria. On the selected sagittal section, a built-in digital caliper recorded in millimeters the RH and LWT (a Perpendicular Line at 3, 5, 7, 10, 13, and 15 mm from the lowest point of the sinus floor). Edentulous spans were further classified as complete edentulous atrophic maxilla (CEM) and partial edentulous atrophic maxilla (PEM). The mixed Linear model was used to test the effects of sex, type of edentulism, edentulous span, and RH on the measurement of the LWT of the sinus.Results: Mean LWT for PEM was 1.71 ± 0.12 mm, and for CEM, 1.57 ± 0.07 mm (P = 0.01). The mixed model yielded significant effect of edentulous span (P = 0.048)...
Yu Qiao - One of the best experts on this subject based on the ideXlab platform.
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a novel robot kinematic calibration method based on common Perpendicular Line model
Industrial Robot-an International Journal, 2018Co-Authors: Chen Shen, Youping Chen, Bing Chen, Yu QiaoAbstract:This paper aims to propose a novel robot kinematic calibration method based on the common Perpendicular Line (CPL) model to improve the absolute accuracy of industrial robots.,The deviation between the nominal and actual twists is considered the CPL transformation, which includes the rotation about the CPL and the translation along the CPL. By using the invariance of the reciprocal product of the two spatial Lines, the previous deviation was analyzed in the neighbor space of the base frame origin. In this space, the Line vector of the CPL contained only four independent parameters: two orientation elements and two moment elements. Thus, the CPL model has four independent parameters for the revolute joint and two parameters for the prismatic joint.,By simulations and experiment conducted on a SCARA robot and a 6-DOF PUMA robot, the effectiveness of the novel method for calibration of industrial robot is validated.,The CPL model avoided the normalization and orthogonalization in the iterative identification procedure. Therefore, identifying the CPL model was not only simpler but also more accurate than that of the traditional model. In addition, the results of the CPL transformation strictly conformed to the constraints of the twist.
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a five axis geometric errors calibration model based on the common Perpendicular Line cpl transformation using the product of exponentials poe formula
International Journal of Machine Tools & Manufacture, 2017Co-Authors: Yu Qiao, Youping Chen, Jixiang Yang, Bing ChenAbstract:Abstract Geometric error calibration is a key procedure to improve machining accuracy of five-axis CNC machine tools. This paper proposes a new position independent geometric errors (PIGEs) calibration model of five-axis serial machine tools based on the product of exponentials (POE) formula. The proposed model is characterized by the common Perpendicular Line (CPL) transformation which is adopted to express the deviation between the nominal axis twist and the actual one. One major advantage of the proposed model is the axis twists in the proposed calibration procedure with CPL model strictly fit the constraints of the revolute axis and prismatic axis, thus the calibration procedure avoids the normalization and orthogonalization as required by existing calibration models based on POE formula. The other advantage of the proposed CPL model is that it only needs 4 independent parameters for PIGEs of a revolute axis and 2 for PIGEs of a prismatic axis, rather than 6 parameters for each axis as required by existing models. Apparently, the decrease of parameters brings a shrink to the scale of the identification coefficient matrix, and thus decreases the calculation amount. The proposed model is validated by simulations and experiments.