PhD Position F/M Mechatronic whole-body co-design of a quadruped robot integrating local compliance for locomanipulation tasks.

PhD Position F/M Mechatronic whole-body co-design of a quadruped robot integrating local compliance for locomanipulation tasks. Download job offer in PDF format Contract type : Fixed-term contract Level of qualifications required : Graduate degree or equivalent Fonction : PhD Position Context The PhD thesis will take place within the Auctus team at the Inria center of the University of Bordeaux (Talence). This thesis falls within the scope of the team's scientific axis on the design and control of robotic systems. The project will benefit from the hardware and software resources of the lab experimental platform. The student will be supervised throughout the PhD by Margot Vulliez and David Daney, researchers specializing in modeling and analysis of mechanisms, mechatronic design, and robot architecture optimization. This PhD is part of a collaborative research project with the Gepetto team at LAAS-CNRS (Toulouse). The PhD candidate will work closely with a second PhD student, primarily based and supervised at Gepetto, and focusing on the development of RL motion generation and simulation-driven co-design tools. The two PhD projects will benefit from regular inputs from researchers across both partner teams. Several visits at the Gepetto team are planned for the PhD student to strengthen this collaboration through hands-on experience with the simulation tool or experimental studies. Assignment Quadruped robots have seen rapid growth over the past decade, after a major breakthrough established with MIT Cheetah [Seok13, Katz19]. They provide robust mobility and remarkable agility in unstructured environments. They are almost systematically based on a similar rigid architecture, equipped with quasi direct drive pancake motors all positioned in the torso to minimize leg inertia [Wensing17]. Such rigid structures favor model accuracy and control tractability [Wensing23], but they also limit impact absorption and prevent the robot from exploiting local flexibility to improve mobility. Although quadrupeds are mature, their performance is plateauing far below that of biological counterparts. Many alternative mechatronic solutions, such as elastic actuators (SEA [Pratt95, Verstraten16], PEA [Mettin10, Ding24], VSA [Vanderborght13]), tensegrity mechanisms [Motro03, Vimbert26], flexible links [Xu22], soft and passive joints [Collins05, Badri-Spröwitz13], have already been proposed in the literature to enhance energy efficiency, improve shock absorption, provide intrinsic compliance, or reduce the robot mass, assembly constraints, and fabrication cost. Embedding such propositions into an active trunk/spine [Ijspeert07, Khoramshahi13] or locally exploiting compliance through flexible paws [Catalano21, Badri-Spröwitz22] or tails [Libby12, Liu25], has shown to increase locomotion speed and acceleration capability [Fisher17, Li23], enhance impact absorption [Sato15, Hua25], or stabilize gaits [Eckert15, Sabelhaus18]. While effective on targeted benchmarks, they remain isolated and fail to integrate into a comprehensive design. These innovations are typically investigated at the component level, without considering whole-body interactions, due to the lack of a co-design methodology that incorporates robust whole-body control policies. This PhD project will leverage recent co-design approaches and modern control methods such as RL to go beyond component-level innovations. It aims at developing a new whole-body quadruped architecture that embodies the use of alternative mechatronic concepts, to improve overall system manipulation and dynamic locomotion capabilities, impact tolerance, and energy efficiency. It will explicitly account for control constraints through realistic simulations of the robot behavior on targeted locomanipulation tasks. Main activities To push the limits of manipulation and high-dynamic locomotion in quadruped robots requires moving beyond conventional rigid legged platforms. This shift calls for the development of new morphologies based on whole-body, multi-functional designs that exploit alternative mechanisms and distributed compliance. This PhD thesis aims to propose, model, and compare different mechatronic propositions through both simulation-based evaluation and experimental calibration. The goal is to develop a novel integrated quadruped design, by adopting a whole-body co-design approach, jointly optimizing mechanical architecture, actuation systems, and control policy. The thesis will be structured in several complementary axes of research: - Simulation-informed development of alternative mechanisms for locomanipulation. The first axis consists of developing different mechatronic solutions that could improve dynamic locomanipulation capabilities, by drawing on insights from biological systems. We envision integrating localized flexibility and damping components (flexible links or soft joints), elastic transmissions (SEA, PEA), alternative kinematic structures (active or passive spines, tails, necks, parallel bar mechanisms), tensegrity mechanisms and tension elements. The localization and characteristics of candidate compliance/tension elements and additional degrees of freedom will be iteratively evaluated, refined, and compared through RL-based motion simulation, based on performance criteria (e.g. motion-force-stiffness range, energy consumption). Through a synthesis methodology, mechanisms will be adjusted to reproduce optimal temporal profiles of force, motion, and stiffness, extracted from RL-generated trajectories. - Experimental characterization of the alternative mechanisms and real-to-sim calibration. We will prototype and characterize the proposed mechanisms with a dual goal: (i) validating and refining their dynamic models through parameter identification on dedicated test benches, including external measurement systems (encoders, force sensors). The refined models will serve in simulation to reduce the real-to-sim gap; (ii) estimating each mechanism's performance and its sensitivity to variation in design or manufacturing parameters, such as used material, prototyping technology, or dimensional tolerances. This sensitivity analysis will inform parameters and levels of noise used in RL policy randomization to improve the robustness and reliability of policy training. It will also provide the minimal accuracy required for part fabrication, thereby relaxing unnecessary and costly precision tolerances on the design. - Whole-body design conceptualization, co-optimization, and prototyping. This final axis will consolidate all technological bricks together into a co-designed whole-body architecture. The new quadruped will move away from conventional designs by tightly integrating manipulation and locomotion capabilities through a global leg-spine-neck dynamic optimization. Building on the previous outcomes, we will first define the quadruped’s kinematic structure, actuation type, sensing modalities, and flexibility distribution, associated with a set of design parameters and a parameterized CAD model. We will then employ available co-design approaches to jointly optimize the architecture, actuation, and control policy through simulation. The optimized full quadruped design will be prototyped, and its motion-force capabilities will be experimentally evaluated on a prescribed workspace. Experimental locomanipulation demonstrations will validate the prototype performance on two applications: outdoor high-speed galloping and flying-object catching. Skills The candidate should have solid skills in mechanical design, prototyping, robot modeling, robotic control, and programming (C++ or Python). Some additional experiences in optimization or in motor/sensor integration would be appreciated. Benefits package • Subsidized meals • Partial reimbursement of public transport costs • Possibility of teleworking and flexible organization of working hours • Professional equipment available (videoconferencing, loan of computer equipment, etc.) • Social, cultural and sports events and activities • Access to vocational training • Social security coverage Remuneration 2300€ / month before taxs Apply for this position Share • Facebook • Linkedin • Twitter • Email General Information • Theme/Domain : Robotics and Smart environments Instrumentation et expérimentation (BAP C) • Town/city : Talence • Inria Center : Centre Inria de l'université de Bordeaux • Starting date : 2026-10-01 • Duration of contract : 3 years • Deadline to apply : 2026-08-31 Warning : you must enter your e-mail address in order to save your application to Inria. Applications must be submitted online on the Inria website. Processing of applications sent from other channels is not guaranteed. Instruction to apply Thank you to send: • Detailed CV • Covering letter • Transcripts/grades of Master's years • Letter of recommendation (if applicable) Defence Security : This position is likely to be situated in a restricted area (ZRR), as defined in Decree No. 2011-1425 relating to the protection of national scientific and technical potential (PPST).Authorisation to enter an area is granted by the director of the unit, following a favourable Ministerial decision, as defined in the decree of 3 July 2012 relating to the PPST. An unfavourable Ministerial decision in respect of a position situated in a ZRR would result in the cancellation of the appointment. Recruitment Policy : As part of its diversity policy, all Inria positions are accessible to people with disabilities. Contacts • Inria Team : AUCTUS • PhD Supervisor : Vulliez Margot / margot.vulliez@inria.fr About Inria Inria, the French national institute for research in digital science and technology, supports the French government in national research and innovation strategies in the digital field, acting as Digital Programs Agency. Inria leads over 300 research and innovation projects with its 3,500 scientists, engineers, and support staff, in partnership with universities and the digital ecosystem (businesses, entrepreneurs, and public stakeholders). Together, we explore strategic fields such as artificial intelligence, cybersecurity, quantum computing, cloud technologies, digital transformation in healthcare, digital twins, and digital technologies for defence. We develop practical solutions such as software, tech startups, partnerships with national companies, and cutting-edge training programmes. Our goal is to drive scientific, technological, and industrial excellence to ensure France’s digital sovereignty.