Petman is an anthropomorphic robot designed to test chemical protective clothing (Fig. 1). Petman will test Individual Protective Equipment (IPE) in an environmentally controlled test chamber, where it will be exposed to chemical agents as it walks and does basic calisthenics. Chemical sensors embedded in the skin of the robot will measure if, when and where chemical agents are detected within the suit. The robot will perform its tests in a chamber under controlled temperature and wind conditions. A treadmill and turntable integrated into the wind tunnel chamber allow for sustained walking experiments that can be oriented relative to the wind. Petman’s skin is temperature controlled and even sweats in order to simulate physiologic conditions within the suit. When the robot is performing tests, a loose fitting Intelligent Safety Harness (ISH) will be present to support or catch and restart the robot should it lose balance or suffer a mechanical failure. The integrated system: the robot, chamber, treadmill/turntable, ISH and electrical, mechanical and software systems for testing IPE is called the Individual Protective Ensemble Mannequin System (Fig. 2) and is being built by a team of organizations.† In 2009 when we began the design of Petman, there was no humanoid robot in the world that could meet the requirements set out for this program. Previous suit testing robots such as Portonman from the Defense Science and Technology Laboratory used external actuation or fixtures to support the robot during exercises. Limitations of these systems include a limited repertoire of behaviors or the compromise of the protective suit

PETMAN : A Humanoid Robot for Testing Chemical Protective Clothing (特集 2足歩行ロボット技術)

Design and Dynamic Analysis of a Compliant Leg Configuration towards the Biped Robot’s Spring-Like Walking

This paper presents the force control strategies and a kind of compliance control strategies of the hydraulic- driven unit (HDU) in the legged robots. The model of HDU is established and the transfer function of the HDU force control system is given. The analysis of the force control strategies is introduced according to the characteristic of the HDU system. Based on the force control strategy called velocity feedback control strategy which performs the best, the virtual model control strategy which is a kind of compliance control strategy is presented to enhance the adaptability of the legged robot. Finally, the experiments are taken on the HDU experiment platform to test the performance of the force control strategies and the compliance control strategy. The landing buffer experiments are taken on the single leg robot to verify the effectiveness of the compliance control strategy. In the landing buffer experiments, the impact force of the single leg robot's knee HDU is about 0.33 time of what it is without the compliance control strategy while landing.

Compliance Control of the Hydraulic-Driven Single Legged Robot


Purpose
The purpose of this paper is to propose a novel jump control method based on Two Mass Spring Damp Inverted Pendulum (TMS-DIP) model, which makes the third generation of hydraulic driven wheel-legged robot prototype (WLR-3P) achieve stable jumping.


Design/methodology/approach
First, according to the configuration of the WLR, a TMS-DIP model is proposed to simplify the dynamic model of the robot. Then the jumping process is divided into four stages: thrust, ascent, descent and compression, and each stage is modeled and solved independently based on TMS-DIP model. Through WLR-3P kinematics, the trajectory of the upper and lower centroids of the TMS-DIP model can be mapped to the joint space of the robot. The corresponding control strategies are proposed for jumping height, landing buffer, jumping attitude and robotic balance, so as to realize the stable jump control of the WLR.


Findings
The TMS-DIP model proposed in this paper can simplify the WLR dynamic model and provide a simple and effective tool for the jumping trajectory planning of the robot. The proposed approach is suitable for hydraulic WLR jumping control. The performance of the proposed wheel-legged jump method was verified by experiments on WLR-3P.


Originality/value
This work provides an effective model (TMS-DIP) for the jump control of WLR-3P. The results showed that the number of landing shock (twice) and the pitch angle fluctuation range (0.44 rad) of center of mass of the jump control method based on TMS-DIP model are smaller than those based on spring-loaded inverted pendulum model. Therefore, the TMS-DIP model makes the jumping process of WLR more stable and gentler.


Stable jump control for the wheel-legged robot based on TMS-DIP model

Design and soft-landing control of underwater legged robot for active buffer landing on seabed

This paper presents a vertical jumping trajectory planning and landing buffer control methods that enable a hydraulic driven single legged robot to execute load-bearing take-off and stable landing motions. After a brief description of the robot, the kinematics and dynamics models of HSLR are established based on the actual structure of the robot. Then the paper describes the details of jumping trajectory planning method based on spring loaded inverted pendulum (SLIP) model, which can realize vertical jump control with a desired height. Moreover, landing buffer strategy based on single legged virtual model is presented to protect robots from the impact damage. Finally, the experimental results show that the proposed method for HSLR can achieve vertical jump to 0.2m as well as a stable landing buffer performance.

Yixiao Fan

Papers

Vertical Jump Control of Hydraulic Single Legged Robot (HSLR)

Compliance Control of the Hydraulic-Driven Single Legged Robot

Stable jump control for the wheel-legged robot based on TMS-DIP model