Live modular Robots! Dr. Houxiang Zhang Dr. Juan Gonzlez-Gmez - PowerPoint PPT Presentation

Live modular Robots! Dr. Houxiang Zhang Dr. Juan González-Gómez Faculty of Mathematics, Informatics School of Engineering and Natural Sciences Universidad Autonoma de Madrid University of Hamburg DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009

Outline Outline 1. Introduction 2. Locomotion in 1D 3. Locomotion in 2D 4. Minimal configurations 5. Cube-M modules 6. Conclusions and current work 2 Live modular Robots! DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009

The Locomotion Problem Modular approach Bio-inspired approach Classic approach CMU Ambler Aramies Polybot Big Dog Dante II 3

Modular Robotics ● Two important aspects: ● Robot morphology ● Controller 4

Morphology Modular Robot classification 2D Topology 3D Topology 1D Topology 1D topology sub-classification Pitch-yaw Yaw-yaw Pitch-Pitch 5

Controller ● Coordination problem : Calculation of the joint's angles to realize a gait:  i  t  ● Classic approach : Mathematical modeling ● Calculation by inverse kinematics ● Disadvantages: The equations are only valid for an specific morphology CPG CPG CPG ● Bio-inspired controllers : CPGs ● Central Pattern Generators ● CPGs control the rhythmic activities ● Ej. The locomotion of the lamprey 6

Hypothesis: Sinusoidal oscillators ● CPGs are replaced by a Simplified model CPG CPG CPG ● Sinusoidal oscillators: ● Advantages : in  2   i  t = A i s T  i  O i ● Few resources required 7

Outline Outline 1. Introduction 2. Locomotion in 1D 3. Locomotion in 2D 4. Minimal configurations 5. Cube-M modules 6. Conclusions and current work 8 Live modular Robots! DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009

Y1 Modules ● One degree of freedom ● Easy to build ● Cheap ● Open and “Free” 9

Electronics & control 10

Cube Revolutions (I) Videos ● Morphology: 8 modules with pitch-pitch connection ● Controller: ● 8 equal oscillators ● Parameters: A ,  ,T 11

Locomotion mechanism ● Locomotion performed by the body wave propagation  x ● Step: V = x ● Mean Speed: T ● Serpenoid curve ● Step calculation: l  x = l s  2  k k c k −∫ 0 o s  c o s  ds l 12

Outline Outline 1. Introduction 2. Locomotion in 1D 3. Locomotion in 2D 4. Minimal configurations 5. Cube-M modules 6. Conclusions and current work 13 Live modular Robots! DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009

Hypercube (I) Demo ● Morphology 8 modules with pitch-yaw connection ● Controller: ● 4 vertical oscillators ● 4 horizontal oscillators ● Parameters: A h ,A v ,  h ,  v ,  vh ,T 14

Locomotion gaits ● Searching : Genetic algorithms ● 5 categories of gaits ● Characterized by the 3D body wave 15

Locomotion mechanism ● 3D Body wave propagation  r ● Linear Step: ● Angular Step:  ● Dimensions: width (w) x length (lx) x heigth (h) 16

Outline Outline 1. Introduction 2. Locomotion in 1D 3. Locomotion in 2D 4. Minimal configurations 5. Cube-M modules 6. Conclusions and future work 17 Live modular Robots! DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009

Minimal configurations ● Configurations with the minimal number of modules that are able to move ● Searching the control space using genetic algorithms ● 5 gaits ● Straight line 18

Minicube-I Demo ● Morphology 2 modules with a Pitch- pitch connection ● Controller: ● Two generators ● Parameters: A ,  ,T 19

Minicube-II Demo ● Morphology: 3 modules with Pitch-yaw- pitch connection ● Controller: ● 3 oscillators ● Parameters: A v ,A h ,  v ,  vh ,T 20

Locomotion gaits Rolling Forward Lateral shifting A v = 40, A h = 0 A v = A h  40  vh = 90,  v = 0  v = 120 A v = A h  60 Turning  vh = 90,  v = 0 Rotating A v = 40, A h = 0 A v = 10, A h = 40 O h = 30,  v = 120 21  vh = 90,  v = 180

Outline Outline 1. Introduction 2. Locomotion in 1D 3. Locomotion in 2D 4. Minimal configurations 5. Cube-M modules 6. Conclusions and current work 22 Live modular Robots! DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009

Cube-M module(I) Low cost mechanical design ● Simple robust modules assembling ● manually and int a quick-to-build, easy-to- handle design Onboard electronics and sensors ● 23

Cube-M module (II) Demo 24

Software Demo ● 1D topology simulator (Based on Open Dynamics Engine [ODE]) ● Generics algorithms: PGAPack ● Mathematical models in Octave/Matlab 25

Outline Outline 1. Introduction 2. Locomotion in 1D 3. Locomotion in 2D 4. Minimal configurations 5. Cube-M modules 6. Conclusions and current work 26 Live modular Robots! DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009

Conclusions The controller based on sinusoidal oscillators is valid for the locomotion of the 1D-topology modular robots ● Very few resources are required for its implementation ● The locomotion gaits are very smooth and natural ● At least 5 different gaits can be achieved  i  t = A i sin  2  T  i  O i 27

Current work Locomotion of 2D Climbing caterpillar Topology modular robots Modular grasping New module design 28

Live modular Robots! Dr. Houxiang Zhang Dr. Juan González-Gómez Faculty of Mathematics, Informatics School of Engineering and Natural Sciences Universidad Autonoma de Madrid University of Hamburg 29 DFKI Bremen – Robotics Innovation Center. Jun, 16th, 2009