Tip-over prevention control for teleoperated excavator based on CoG and ZMP prediction

This paper describes tip-over prevention control of a teleoperated excavator based on center of gravity (CoG) and zero moment point (ZMP) prediction. This method predicts a future CoG and ZMP when an operation input is given. This allows the determination of the risk of tip-over by the operation input before an excavator moves. When the risk is detected, the operation input to the actuator is modified or stopped automatically to prevent from tip-over. Future CoG and ZMP is predicted by computing the movement of a teleoperated excavator based on an approximate excavator movement model. The proposed method successfully demonstrates tip-over prevention via scaled model experiments of the hydraulic drive

Differential remodelling of peroxisome function underpins the environmental and metabolic adaptability of diplonemids and kinetoplastids

The remodelling of organelle function is increasingly appreciated as a central driver of eukaryotic biodiversity and evolution. Kinetoplastids including Trypanosoma and Leishmania have evolved specialized peroxisomes, called glycosomes. Glycosomes uniquely contain a glycolytic pathway as well as other enzymes, which underpin the physiological flexibility of these major human pathogens. The sister group of kinetoplastids are the diplonemids, which are among the most abundant eukaryotes in marine plankton. Here we demonstrate the compartmentalization of gluconeogenesis, or glycolysis in reverse, in the peroxisomes of the free-living marine diplonemid, Diplonema papillatum. Our results suggest that peroxisome modification was already under way in the common ancestor of kinetoplastids and diplonemids, and raise the possibility that the central importance of gluconeogenesis to carbon metabolism in the heterotrophic free-living ancestor may have been an important selective driver. Our data indicate that peroxisome modification is not confined to the kinetoplastid lineage, but has also been a factor in the success of their free-living euglenozoan relatives

Estimation and Sharpening of Blur in Degraded Images Captured by a Camera on a Moving Object

In this research, we aim to propose an image sharpening method to make it easy to identify concrete cracks from blurred images captured by a moving camera. This study is expected to help realize social infrastructure maintenance using a wide range of robotic technologies, and to solve the future labor shortage and shortage of engineers. In this paper, a method to estimate parameters of motion blur for Point Spread Function (PSF) is mainly discussed, where we assume that there are two main degradation factors caused by the camera, out-of-focus blur and motion blur. A major contribution of this paper is that the parameters can properly be estimated from a sub-image of the object under inspection if the sub-image contains uniform speckled texture. Here, the cepstrum of the sub-image is fully utilized. Then, a filter convoluted PSF which consists of convolution with PSF (motion blur) and PSF (out-of focus blur) can be utilized for deconvolution of the blurred image for sharpening with significant effect. PSF (out-of-focus blur) is a constant function unique to each camera and lens, and can be confirmed before or after shooting. PSF (motion blur), on the other hand, needs to be estimated on a case-by-case basis since the amount and direction of camera movement varies depending on the time of shooting. Previous research papers have sometimes encountered difficulties in estimating the parameters of motion blur because of the emphasis on generality. In this paper, the main object is made of concrete, and on the surface of it there are speckled textures. We hypothesized that we can narrow down the candidates of parameters of motion blur by using these speckled patterns. To verify this hypothesis, we conducted experiments to confirm and examine the following two points using a general-purpose camera used in actual bridge inspections: 1. Influence on the cepstrum when the isolated point-like texture unique to concrete structures is used as a feature point. 2. Selection method of multiple images to narrow down the candidate minima of the cepstrum. It is novel that the parameters of motion blur can be well estimated by using the unique speckled pattern on the surface of the object

オクナイ カンキヨウ オ イドウ スル ロボツト ノ シカク システム ニ カンスル ケンキユウ

筑波大学工学博士学位論文・昭和63年3月25日授与 (甲第549号