This paper proposes a novel continuous footholds optimization method for legged robots to expand their walking ability on complex terrains.The algorithm can efficiently run onboard and online by using terrain percepti...This paper proposes a novel continuous footholds optimization method for legged robots to expand their walking ability on complex terrains.The algorithm can efficiently run onboard and online by using terrain perception information to protect the robot against slipping or tripping on the edge of obstacles,and to improve its stability and safety when walking on complex terrain.By relying on the depth camera installed on the robot and obtaining the terrain heightmap,the algorithm converts the discrete grid heightmap into a continuous costmap.Then,it constructs an optimization function combined with the robot’s state information to select the next footholds and generate the motion trajectory to control the robot’s locomotion.Compared with most existing footholds selection algorithms that rely on discrete enumeration search,as far as we know,the proposed algorithm is the first to use a continuous optimization method.We successfully implemented the algorithm on a hexapod robot,and verified its feasibility in a walking experiment on a complex terrain.展开更多
The Golden Jackal (Canis aureus Linnaeus, 1758), which belongs to the Canidae family, is an opportunist carnivore in the Gaza Strip (365 square kilometers). The current study aims at giving notes on the occurrence and...The Golden Jackal (Canis aureus Linnaeus, 1758), which belongs to the Canidae family, is an opportunist carnivore in the Gaza Strip (365 square kilometers). The current study aims at giving notes on the occurrence and some ecological aspects of the species in the Gaza Strip, Palestine. The study, which lasted 14 years (2007-2020), is descriptive and cumulative in its style. It was based on frequent field visits, direct observations and meetings and discussions with wildlife hunters, farmers and other stakeholders. The findings of the study show that Gazans are familiar with the Golden Jackal to the extent that a Gazan family holds the Arabic name of the animal, which is “Wawi”. The Golden Jackal was sometimes encountered and hunted in the eastern parts of the Gaza Strip, which are characterized by the presence of wilderness areas, intensive agriculture, poultry pens and solid waste landfills. Like other a few mammalian faunas, the adult Golden Jackals enter the Gaza Strip through gaps in or burrows beneath the metal borders separating the Gaza Strip from the rest of the Palestinian Territories and Egypt. Gaza zoos were found to harbor tens of Golden Jackals trapped or hunted by clever wildlife hunters using different means such as wire cages known locally as “maltash” and foothold traps with metal jaws that may cause lesions to the trapped animals. Poisoning and shooting were also common methods used to control the jackals and other carnivores causing harm to agriculture and livestock. The animal was known among the Gazans as an omnivore, feeding on wild and domestic animals in addition to plant materials, garbage and carrions. In conclusion, the study recommends the need to raise ecological awareness to preserve the Golden jackal and to adopt safe control measures for jackals and other carnivores, including the construction of protective fences for agricultural fields and animal pens.展开更多
You drive up to the counter, roll down your car's window and place an order for a double cheeseburger and fries. Minutes later you've paid and collected your very fast food, rolled up your window and driven of...You drive up to the counter, roll down your car's window and place an order for a double cheeseburger and fries. Minutes later you've paid and collected your very fast food, rolled up your window and driven off-and your feet have not even touched the ground.展开更多
With the successful launch of Tiangong-1 (Heavenly Palace-1) unmanned module on September 29,China took a significant step forward in realizing its ambitions in space.China’s manned space program consists of three st...With the successful launch of Tiangong-1 (Heavenly Palace-1) unmanned module on September 29,China took a significant step forward in realizing its ambitions in space.China’s manned space program consists of three steps.The first step,to send an astronaut into space,was achieved in 2003.展开更多
基金supported by the National Key R&D Program of China(Grant No.2021YFF0306202).
文摘This paper proposes a novel continuous footholds optimization method for legged robots to expand their walking ability on complex terrains.The algorithm can efficiently run onboard and online by using terrain perception information to protect the robot against slipping or tripping on the edge of obstacles,and to improve its stability and safety when walking on complex terrain.By relying on the depth camera installed on the robot and obtaining the terrain heightmap,the algorithm converts the discrete grid heightmap into a continuous costmap.Then,it constructs an optimization function combined with the robot’s state information to select the next footholds and generate the motion trajectory to control the robot’s locomotion.Compared with most existing footholds selection algorithms that rely on discrete enumeration search,as far as we know,the proposed algorithm is the first to use a continuous optimization method.We successfully implemented the algorithm on a hexapod robot,and verified its feasibility in a walking experiment on a complex terrain.
文摘The Golden Jackal (Canis aureus Linnaeus, 1758), which belongs to the Canidae family, is an opportunist carnivore in the Gaza Strip (365 square kilometers). The current study aims at giving notes on the occurrence and some ecological aspects of the species in the Gaza Strip, Palestine. The study, which lasted 14 years (2007-2020), is descriptive and cumulative in its style. It was based on frequent field visits, direct observations and meetings and discussions with wildlife hunters, farmers and other stakeholders. The findings of the study show that Gazans are familiar with the Golden Jackal to the extent that a Gazan family holds the Arabic name of the animal, which is “Wawi”. The Golden Jackal was sometimes encountered and hunted in the eastern parts of the Gaza Strip, which are characterized by the presence of wilderness areas, intensive agriculture, poultry pens and solid waste landfills. Like other a few mammalian faunas, the adult Golden Jackals enter the Gaza Strip through gaps in or burrows beneath the metal borders separating the Gaza Strip from the rest of the Palestinian Territories and Egypt. Gaza zoos were found to harbor tens of Golden Jackals trapped or hunted by clever wildlife hunters using different means such as wire cages known locally as “maltash” and foothold traps with metal jaws that may cause lesions to the trapped animals. Poisoning and shooting were also common methods used to control the jackals and other carnivores causing harm to agriculture and livestock. The animal was known among the Gazans as an omnivore, feeding on wild and domestic animals in addition to plant materials, garbage and carrions. In conclusion, the study recommends the need to raise ecological awareness to preserve the Golden jackal and to adopt safe control measures for jackals and other carnivores, including the construction of protective fences for agricultural fields and animal pens.
文摘You drive up to the counter, roll down your car's window and place an order for a double cheeseburger and fries. Minutes later you've paid and collected your very fast food, rolled up your window and driven off-and your feet have not even touched the ground.
文摘With the successful launch of Tiangong-1 (Heavenly Palace-1) unmanned module on September 29,China took a significant step forward in realizing its ambitions in space.China’s manned space program consists of three steps.The first step,to send an astronaut into space,was achieved in 2003.
