--In order for a humanoid robot to perform loco-manipulation such as moving an object while walking, it is necessary to account for sustained or alternating external forces other than ground-feet reaction, resulting from humanoid-object contact interactions. In this letter, we propose a bipedal control strategy for humanoid loco-manipulation that can cope with such external forces. First, the basic formulas of the bipedal dynamics, i.e., linear inverted pendulum mode and divergent component of motion, are derived, taking into account the effects of external manipulation forces. Then, we propose a pattern generator to plan center of mass trajectories consistent with the reference trajectory of the manipulation forces, and a stabilizer to compensate for the error between desired and actual manipulation forces. The effectiveness of our controller is assessed both in simulation and loco-manipulation experiments with real humanoid robots. OVING large and heavy objects is a hard task for humans, and is expected to be left to humanoid robots.

This paper presents a study on the use of the Talos humanoid robot for performing assistive sit-to-stand or stand-to-sit tasks. In such tasks, the human exerts a large amount of force (100--200 N) within a very short time (2--8 s), posing significant challenges in terms of human unpredictability and robot stability control. To address these challenges, we propose an approach for finding a spatial reference for the robot, which allows the robot to move according to the force exerted by the human and control its stability during the task. Specifically, we focus on the problem of finding a 1D manifold for the robot, while assuming a simple controller to guide its movement on this manifold. To achieve this, we use a functional representation to parameterize the manifold and solve an optimization problem that takes into account the robot's stability and the unpredictability of human behavior. We demonstrate the effectiveness of our approach through simulations and experiments with the Talos robot, showing robustness and adaptability.

Intentionally applying impacts while maintaining balance is challenging for legged robots. This study originated from observing experimental data of the humanoid robot HRP-4 intentionally hitting a wall with its right arm while standing on two feet. Strangely, violating the usual zero moment point balance criteria did not systematically result in a fall. To investigate this phenomenon, we propose the zero-step capture region for non-coplanar contacts, defined as the center of mass (CoM) velocity area, and validated it with push-recovery experiments employing the HRP-4 balancing on two non-coplanar contacts. To further enable on-purpose impacts, we compute the set of candidate post-impact CoM velocities accounting for frictional-impact dynamics in three dimensions, and restrict the entire set within the CoM velocity area to maintain balance with the sustained contacts during and after impacts. We illustrate the maximum contact velocity for various HRP-4 stances in simulation, indicating potential for integration into other task-space whole-body controllers or planners. This study is the first to address the challenging problem of applying an intentional impact with a kinematic-controlled humanoid robot on non-coplanar contacts.

We have developed biped robots with a passive dynamic walking mechanism. This study proposes a compass model with a wobbling mass connected to the upper body and oscillating in the horizontal direction to clarify the influence of the horizontal dynamics of the upper body on bipedal walking. The limit cycles of the model were numerically searched, and their stability and energy efficiency was investigated. Several qualitatively different limit cycles were obtained depending mainly on the spring constant that supports the wobbling mass. Specific types of solutions decreased the stability while reducing the risk of accidental falling and improving the energy efficiency. The obtained results were attributed to the wobbling mass moving in the opposite direction to the upper body, thereby preventing large changes in acceleration and deceleration while walking. The relationship between the locomotion of the proposed model and the actual biped robot and human gaits was investigated.

This paper presents a framework that allows online dynamic-stability-constrained optimal trajectory planning of a mobile manipulator robot working on rough terrain. First, the kinematics model of a mobile manipulator robot, and the Zero Moment Point (ZMP) stability measure are presented as theoretical background. Then, a sampling-based quasi-static planning algorithm modified for stability guarantee and traction optimization in continuous dynamic motion is presented along with a mathematical proof. The robot's quasi-static path is then used as an initial guess to warm-start a nonlinear optimal control solver which may otherwise have difficulties finding a solution to the stability-constrained formulation efficiently. The performance and computational efficiency of the framework are demonstrated through an application to a simulated timber harvesting mobile manipulator machine working on varying terrain. The results demonstrate feasibility of online trajectory planning on varying terrain while satisfying the dynamic stability constraint.

Mix the rise of e-commerce in Japan with a chronic labor shortage and a graying society and what do you get? "I'm delivering delicious food," announced CarriRo Deli, a robot the size of a cooler box that was navigating a South Korean apartment complex in April, bringing food and drinks to residents during a trial of its "last-mile" delivery service. The robot's maker, Tokyo-based ZMP Inc., has already held a number of delivery trials at university campuses and elsewhere in Japan and is looking for partners to help it develop the business further. Aside from having a 50 kg cargo capacity and a speed of 6 kph, the robot speaks short phrases like "hello" and "thank you" and has LED eyes, a feature aimed at making it more lifelike and engaging when interacting with people. "It would be scary if a simple box was running around places," ZMP Manager Hiromasa Iwano explained at a gathering in Tokyo in late July, adding the company took into account how people would react to the robots. "We wanted to create a robot that is well-received, socially." ZMP CEO Hisashi Taniguchi said at the same event that CarriRo Deli was the world's only autonomous delivery robot with eyes when it was revealed last year, noting that although eyes had long been a feature industrial designers avoided, others are now following suit.

Tokyo-based venture ZMP Inc. may begin field testing a self-driving delivery robot in August intended as an alternative to aerial delivery drones as Japan grapples with a growing labor shortage. The box-shaped CarriRo Delivery robot, which is 133 cm long and 109 cm high, is designed to run on sidewalks and carry loads of up to 100 kg, ZMP said. "Our delivery robot is more suitable than drones when it comes to delivering heavy products like food items," said ZMP Chief Executive Officer Hisashi Taniguchi. The company has teamed up with sushi delivery firm Ride On Express Co. to test a prototype of the autonomous vehicle on private property. The robot, which is equipped with cameras and sensors and can steer itself at a maximum speed of 6 kph, selects delivery routes on its own using a pre-loaded map. It can be controlled remotely when needed, according to ZMP, which is also developing self-driving car technologies.

With its Shinkansen'bullet trains' and melodious subway system, Tokyo already has some of the world's greatest public transport infrastructure. But the heavily populated city will be pushed to its limits come 2020, when the world descends on the Japanese capital as it plays host to the Olympic games. One company looking to capitalise on the influx of tourists is robotics firm ZMP Inc. According to Reuters, it's planing to team up with Tokyo's Hinomaru Kotso cab firm to update its fleet of 600 cars with driverless technology. ZMP has already had driverless cars on Tokyo's streets, but each had a driver ready to wrestle control should the AI go wayward. It will begin testing truly driverless cars this year, ahead of its ambitious 2020 goal.

Hisashi Taniguchi used a sabbatical from developing software for driverless taxis and drones to take a pilgrimage to a Buddhist temple in western Japan. He shaved his head, donned black robes and studied to become its leader. He passed the test, yet within a week was back at the Tokyo offices of ZMP Inc., overseeing his robotics company in the more typical garb of jeans and red Converse sneakers. As ZMP's founder and chief executive officer, he tries to sync millenniums-old teachings with efforts to make artificial intelligence part of everyday life. "The temple teaches you that if you shine, you'll shed light on those around you," Taniguchi, 52, said.

Hisashi Taniguchi took a sabbatical from developing software for driverless taxis and drones to pilgrimage to a Buddhist temple in western Japan. He shaved his head, donned black robes and studied to become the shrine's leader. He passed the test, yet within a week was back at the Tokyo offices of ZMP Inc., overseeing his robotics company in a more-typical wardrobe of jeans and red Converse sneakers. As ZMP's founder and chief executive officer, he tries to sync millennia-old teachings with efforts to make artificial intelligence part of everyday life. "The temple teaches you that if you shine, you'll shed light on those around you," Taniguchi, 52, said.