Toward Anthropomimetic Robotics: Development, Simulation, and Control of a Musculoskeletal Torso

Abstract

A version of this paper with color figures is available online at http://dx.doi.org/10.1162/ artl_a_00088. Subscription required.Abstract Anthropomimetic robotics differs from conventional approaches by capitalizing on the replication of the inner structures of the human body, such as muscles, tendons, bones, and joints. Here we present our results of more than three years of research in constructing, simulating, and, most importantly, controlling anthropomimetic robots. We manufactured four physical torsos, each more complex than its predecessor, and developed the tools required to simulate their behavior. Furthermore, six different control approaches, inspired by classical control theory, machine learning, and neuroscience, were developed and evaluated via these simulations or in small-scale setups. While the obtained results are encouraging, we are aware that we have barely exploited the potential of the anthropomimetic design so far. But, with the tools developed, we are confident that this novel approach will contribute to our understanding of morphological computation and human motor control in the future.

Anthrob - A printed anthropomimetic robot

“…All muscle units are controlled by distributed, custom-built Electronic Control Units (ECUs) which are interfaced via a Controller Area Network (CAN) [14], [1]. Each ECU is capable of controlling two muscle units and is equipped with a microcontroller, a CAN interface, motor drivers for two brushed DC motors, several Analog/Digital (A/D) converters for analog sensor connection and two integrated Hall-effectbased measurement devices in the motor loop for motor current feedback (see also subsection II-C).…”

“…To match the force and stiffness requirements of the individual muscles, appropriate ring configurations were selected for each muscle based on the experimental results (see Table II). Similar to the muscle units used in other musculoskeletal robots, the muscle is contracted by coiling the tendon on the motor spindle [1], [7]. Therefore, the maximum linear velocity and force applied by the tendon depend on the spindle radius as well as on the maximum velocity and torque of the gear output shaft which in turn is defined by the used actuator (DC motor and gear).…”

“…This subclass replicates the human skeletal and muscular system with an unprecedented level of detail and are therefore sometimes referred to as musculoskeletal or anthropomimetic robots [5]. Prominent examples for this class of robots are the robots Kenta, Kotaro, Kojiro [6], Kenzoh and Kenshiro [7] built by the Jouhou System Kougaku Laboratory of the University of Tokyo (JSK) since 2002 and the ECCEs developed by the EU-funded project Eccerobot between 2009 and 2012 [1]. However, even though these robots are extremely impressive artifacts, provably stable control strategies have so far not been developed.…”

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Abstract-Anthropomimetic robotics differ from conventional approaches by capitalizing on the replication of the inner structures of the human body, such as muscles, tendons, bones and joints [1]. Prominent examples for this class of robots are the robots developed at the JSK laboratory of the University of Tokyo and the robots developed by the EU-funded project Embodied Cognition in a Compliantly Engineered Robot (Eccerobot).

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Simple or Complex Bodies? Trade-offs in Exploiting Body Morphology for Control

“…At the same time, the bodies themselves tend to be much more complex in terms of geometrical as well as dynamical properties. This has motivated the design of compliant, tendon-driven robots like ECCE [51] or Kenshiro [35], and soft, deformable robots like Octopus (e.g., [29]) (we are moving from left to right in Fig. 1).…”