Diseño e integración de actuadores Quasi-Direct Drive propioceptivos en un robot bípedo de alta dinámica.
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
En la última década, la robótica bípeda ha experimentado un progreso gigante. El desarrollo de plataformas como Atlas (Boston Dynamics), Cassie (Agility Robotics) o Tron 1 (Limx Dynamics) han mostrado que los principales desafíos siguen siendo la estabilidad, planificación de trayectorias, eficiencia energética, reducción de masa y últimamente los tipos de actuadores. En este escenario, los actuadores Quasi Direct Drive (QDD) se han transformado en un hito tecnológico al permitir transmisiones bajas y compactas, con alta densidad de torque, bajo peso y buena eficiencia energética, condiciones críticas para lograr movimientos rápidos y controlados en tiempo real. Universidades reconocidas como MIT, Stanford, UCLA o empresas privadas como Boston Dynamics han liderado estas investigaciones, estableciendo un estándar que enseña e inspira desarrollos a nivel global.
En este contexto, la presente memoria aborda el diseño y validación de un actuador QDD propioceptivo e integrado en el robot bípedo B1P0 de 6 grados de libertad, cumpliendo los objetivos de: (i) comunicación CAN multi-driver operativa; (ii) modelo 3D e integración mecánica; (iii) control independiente por eje con demostración funcional; y (iv) un actuador de alta densidad de torque capaz de retroalimentar su posición con exactitud en tiempo real. El actuador desarrollado con un reductor planetario 9:1 impreso en 3D alcanza una densidad de torque de 20.9 [Nm/kg], con aproximadamente un 95 % de eficiencia frente al motor desnudo (sin reductor) que genera 5.3 [Nm/kg]. Concluyendo además, que el actuador construido entrega 8.8 veces más torque útil sin penalizar corriente.
El chasis modular de tres niveles (potencia, control y sensores) permitió fácil mantenimiento y alta escalabilidad; el sistema entra de forma confiable en lazo cerrado y ejecuta trayectorias por CAN (video demo en el repositorio). En conjunto, B1P0 constituye hasta donde se tiene registro, el primer prototipo de robot bípedo de esta envergadura en Chile, desarrollado íntegramente en el Laboratorio de Control Digital Aplicado (L.C.D.A.) de la Facultad de Ingeniería de la Universidad de Concepción, dejando una base sólida para iterar en: estructura y materiales livianos, simulaciones avanzadas, sistemas de control, visión por computadora e inteligencia artificial.
Over the last decade, bipedal robotics has experienced tremendous progress. The development of platforms such as Atlas (Boston Dynamics), Cassie (Agility Robotics), and Tron 1 (Limx Dynamics) have shown that the main challenges remain stability, trajectory planning, energy efficiency, mass reduction, and, more recently, actuator types. In this context, Quasi Direct Drive (QDD) actuators have become a technological milestone, enabling low and compact transmissions with high torque density, low weight, and good energy efficiency—critical conditions for achieving rapid, controlled movements in real time. Renowned universities such as MIT, Stanford, and UCLA, as well as private companies such as Boston Dynamics, have led this research, setting a standard that teaches and inspires developments globally. In this context, this paper addresses the design and validation of a proprioceptive QDD actuator integrated into the 6-degree-of-freedom B1P0 biped robot, fulfilling the objectives of: (i) operational multi-driver CAN communication; (ii) 3D model and mechanical integration; (iii) independent axis control with functional demonstration; and (iv) a high-torque-density actuator capable of accurate position feedback in real time. The developed actuator with a 3D-printed 9:1 planetary gearbox achieves a torque density of 20.9 [Nm/kg], with approximately 95% efficiency compared to the bare motor (without gearbox) that generates 5.3 [Nm/kg]. Furthermore, it is concluded that the constructed actuator delivers 8.8 times more useful torque without any current penalty. The three-level modular chassis (power, control, and sensors) allowed for easy maintenance and high scalability. The system reliably enters a closed loop and executes trajectories via CAN (demo video in the repository). Overall, B1P0 constitutes the first bipedal robot of this size in Chile, developed entirely in the Applied Digital Control Laboratory (LCDA) of the Faculty of Engineering at the University of Concepción, leaving a solid foundation for iterating in: lightweight structure and materials, advanced simulations, control systems, computer vision, and artificial intelligence.
Over the last decade, bipedal robotics has experienced tremendous progress. The development of platforms such as Atlas (Boston Dynamics), Cassie (Agility Robotics), and Tron 1 (Limx Dynamics) have shown that the main challenges remain stability, trajectory planning, energy efficiency, mass reduction, and, more recently, actuator types. In this context, Quasi Direct Drive (QDD) actuators have become a technological milestone, enabling low and compact transmissions with high torque density, low weight, and good energy efficiency—critical conditions for achieving rapid, controlled movements in real time. Renowned universities such as MIT, Stanford, and UCLA, as well as private companies such as Boston Dynamics, have led this research, setting a standard that teaches and inspires developments globally. In this context, this paper addresses the design and validation of a proprioceptive QDD actuator integrated into the 6-degree-of-freedom B1P0 biped robot, fulfilling the objectives of: (i) operational multi-driver CAN communication; (ii) 3D model and mechanical integration; (iii) independent axis control with functional demonstration; and (iv) a high-torque-density actuator capable of accurate position feedback in real time. The developed actuator with a 3D-printed 9:1 planetary gearbox achieves a torque density of 20.9 [Nm/kg], with approximately 95% efficiency compared to the bare motor (without gearbox) that generates 5.3 [Nm/kg]. Furthermore, it is concluded that the constructed actuator delivers 8.8 times more useful torque without any current penalty. The three-level modular chassis (power, control, and sensors) allowed for easy maintenance and high scalability. The system reliably enters a closed loop and executes trajectories via CAN (demo video in the repository). Overall, B1P0 constitutes the first bipedal robot of this size in Chile, developed entirely in the Applied Digital Control Laboratory (LCDA) of the Faculty of Engineering at the University of Concepción, leaving a solid foundation for iterating in: lightweight structure and materials, advanced simulations, control systems, computer vision, and artificial intelligence.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Electrónico/a.
Keywords
Robótica, Robots Diseño, Máquina Piezas