Lifelike Agility and Play on Quadrupedal Robots using Reinforcement Learning and Generative Pre-trained Models

Summarizing knowledge from animals and human beings inspires robotic innovations. In this work, we propose a framework for driving legged robots act like real animals with lifelike agility and strategy in complex environments. Inspired by large pre-trained models witnessed with impressive performance in language and image understanding, we introduce the power of advanced deep generative models to produce motor control signals stimulating legged robots to act like real animals. Unlike conventional controllers and end-to-end RL methods that are task-specific, we propose to pre-train generative models over animal motion datasets to preserve expressive knowledge of animal behavior. The pre-trained model holds sufficient primitive-level knowledge yet is environment-agnostic. It is then reused for a successive stage of learning to align with the environments by traversing a number of challenging obstacles that are rarely considered in previous approaches, including creeping through narrow spaces, jumping over hurdles, freerunning over scattered blocks, etc. Finally, a task-specific controller is trained to solve complex downstream tasks by reusing the knowledge from previous stages. Enriching the knowledge regarding each stage does not affect the usage of other levels of knowledge. This flexible framework offers the possibility of continual knowledge accumulation at different levels. We successfully apply the trained multi-level controllers to the MAX robot, a quadrupedal robot developed in-house, to mimic animals, traverse complex obstacles, and play in a designed challenging multi-agent Chase Tag Game, where lifelike agility and strategy emerge on the robots. The present research pushes the frontier of robot control with new insights on reusing multi-level pre-trained knowledge and solving highly complex downstream tasks in the real world

Intrusion related gold deposits in the Tanami and Kurundi-Kurinelli goldfields, Northern Territory, Australia: Constraints from LA-ICPMS analysis of fluid inclusions

Gold deposits in the Tanami and Kurundi-Kurinelli goldfields of the Northern Territory, Australia, have geological and geochemical characteristics that distinguish them from the typical vein-hosted, orogenic gold deposits that occur in other parts of Australia. This study used cathodoluminescence (CL) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) analyses of fluid inclusions to investigate the source of mineralising fluids from both the highly mineralised Tanami goldfield and weakly mineralised Kurundi-Kurinelli goldfields in northern Australia. Cathodoluminescence showed three generations of quartz in fractured and mineralised veins from the Groundrush deposit in the Tanami goldfield but the remaining deposits had uniform dark CL images. The LA-ICPMS trace element data indicate an evolution from B-As–enriched, magmatic fluid to a highly Sr-Baenriched fluid which results from interaction with sedimentary rocks. The fluids from both regions have chlorinity normalised Zn and Pb concentrations at the magmatic end of the metamorphic – magmatic mixing trend for these elements. This is in agreement with previous studies showing that gold mineralisation is coeval with magmatism in the Tanami region. The relatively high salinity of the fluids in both the Tanami and Kurundi – Kurinelli goldfields, and their trace element contents indicates that the deposits in both regions are intrusionrelated gold deposits. The higher gold endowment of the Tanami region may result from the multiple goldmineralisation events in this region whereas fluid flow associated with mineralisation in the Kurundi – Kurinelli goldfields appears to be of limited extent.This work was financially supported by Chinese Academy of Sciences President’s International Fellowship Initiative (Grant No. 2017VCB0018) to TPM, and by the National Natural Science Foundation of China (41773058), the Science and Technology Foundation of Guizhou Province ([2013]3083), the Opening Foundation of State Key Laboratory of Ore Deposit Geochemistry, and the Institute of Geochemistry, Chinese Academy of Sciences (201504)

In-situ analysis of major and trace elements in fluid inclusion and quartz: LA-ICP-MS method and applications to ore deposits.

LA-ICP-MS (Laser ablation-inductively coupled plasma-mass spectrometry) analysis of fluid inclusion is characterized by high precision, low detection limit and simultaneous measurement of multiple elements, which has remarkable advantages in revealing the specific mineralization processes. Based on using synthetic NaCl-H2O-Rb-Cs and NaCl-KC1-CaCl2-H2O-Rb-Cs fluid inclusions in quartz, a reliable analytical method of quantitatively determing major and trace elements in single fluid inclusion by LA-ICP-MS was established. In this method, external standard NIST610 and internal standard Na were used. The Na content was obtained from microthermometric measurement and calculated using the charge-balancing method. Analytical results show that the accuracy is within 16% and the precision is better than 7% RSD. In addition, combined with using the external standard NIST610 and a natural quartz standard, an analytical method for determing trace elements in quartz was also established. The accuracy for Li, Al and Ti is within 10% and the precision is better than 5% RSD. The above methods were applied to study the Cu and Mo mineralization mechanisms in the Wangjiazhuang Cu-Mo deposit in Luxi Block, eastern North China Craton. The results show that Cu is enriched in vapor-rich fluid inclusions, whereas Mo is concentrated in daughter mineral-bearing fluid inclusions, indicating that Cu was prone to be carried by vapor while Mo was likely carried by brine. This property is thus likely responsible for the depositional separation of Cu and Mo in the deposit. In addition, from the magmatic quartz to the ore-forming and then to the post-ore-forming quartz, the Ti contents decrease while the Al contents increase, suggesting the precipitation of Cu and Mo was also affected by the temperature and pH changes of the fluid