How can robots use their motors and sensors to move around in an unstructured environment? You will understand how to design robot bodies and behaviors that recruit limbs and more general appendages to apply physical forces that confer reliable mobility in a complex and dynamic world. We develop an approach to composing simple dynamical abstractions that partially automate the generation of complicated sensorimotor programs. Specific topics that will be covered include: mobility in animals and robots, kinematics and dynamics of legged machines, and design of dynamical behavior via energy landscapes.
This course is part of the Robotics Specialization
Robotics: Mobility
Offered By
About this Course
3.8
412 ratings
Skills you will gain
Serial Line Internet Protocol (SLIP)RoboticsRobotMatlab
Syllabus - What you will learn from this course
Week
1Introduction: Motivation and Background
We start with a general consideration of animals, the exemplar of mobility in nature. This leads us to adopt the stance of bioinspiration rather than biomimicry, i.e., extracting principles rather than appearances and applying them systematically to our machines. A little more thinking about typical animal mobility leads us to focus on appendages – limbs and tails – as sources of motion. The second portion of the week offers a bit of background on the physical and mathematical foundations of limbed robotic mobility. We start with a linear spring-mass-damper system and consider the second order ordinary differential equation that describes it as a first order dynamical system. We then treat the simple pendulum – the simplest revolute kinematic limb – in the same manner just to give a taste for the nature of nonlinear dynamics that inevitably arise in robotics. We’ll finish with a treatment of stability and energy basins.
Link to bibliography: https://www.coursera.org/learn/robotics-mobility/resources/pqYOc
8 videos (Total 104 min), 3 readings, 5 quizzes
8 videos
1.0.0 What you will learn this week3m
1.1.1 Why and how do animals move?10m
1.1.2 Bioinspiration9m
1.1.3 Legged Mobility: dynamic motion and the management of energy17m
1.2.1 Review LTI Mechanical Dynamical Systems26m
1.2.2 Introduce Nonlinear Mechanical Dynamical Systems: the dissipative pendulum in gravity22m
1.2.3 Linearization & Normal Forms11m
3 readings
Setting up your MATLAB environment10m
MATLAB Tutorial I - Getting Started with MATLAB10m
MATLAB Tutorial II - Programming10m
5 practice exercises
1.1.1 Why and how do animals move8m
1.1.2 Bioinspiration8m
1.1.3 Legged Mobility: dynamic motion and the management of energy8m
1.2.2 Nonlinear mechanical systems8m
1.2.3 Linearizations4m
Week
2Behavioral (Templates) & Physical (Bodies)
We’ll start with behavioral components that take the form of what we call “templates:” very simple mechanisms whose motions are fundamental to the more complex limbed strategies employed by animal and robot locomotors. We’ll focus on the “compass gait” (the motion of a two spoked rimless wheel) and the spring loaded inverted pendulum – the abbreviated versions of legged walkers and legged runners, respectively.We’ll then shift over to look at the physical components of mobility. We’ll start with the notion of physical scaling laws and then review useful materials properties and their associated figures of merit. We’ll end with a brief but crucial look at the science and technology of actuators – the all important sources of the driving forces and torques in our robots.
Link to bibliography: https://www.coursera.org/learn/robotics-mobility/resources/pqYOc
8 videos (Total 63 min), 7 quizzes
8 videos
2.1.1 Walking like a rimless wheel15m
2.1.2 Running like a spring-loaded pendulum11m
2.1.3 Controlling the spring-loaded inverted pendulum8m
2.2.1 Metrics and Scaling: mass, length, strength3m
2.2.2 Materials, manufacturing, and assembly5m
2.2.3 Design: figures of merit, robustness3m
2.3.1 Actuator technologies10m
7 practice exercises
2.1.1 Walking like a rimless wheel8m
2.1.2 Running like a spring-loaded pendulum8m
2.1.3 Controlling the spring-loaded inverted pendulum8m
2.2.1 Metrics and Scaling: mass, length, strength8m
2.2.2 Materials, manufacturing, and assembly8m
2.2.3 Design: figures of merit, robustness12m
2.3.1 Actuator technologies8m
Week
3Anchors: Embodied Behaviors
Now we’ll put physical links and joints together and consider the geometry and the physics required to understand their coordinated motion. We’ll learn about the geometry of degrees of freedom. We’ll then go back to Newton and learn a compact way to write down the physical dynamics that describes the positions, velocities and accelerations of those degrees of freedom when forced by our actuators.Of course there are many different ways to put limbs and bodies together: again, the animals can teach us a lot as we consider the best morphology for our limbed robots. Sprawled posture runners like cockroaches have six legs which typically move in a stereotyped pattern which we will consider as a model for a hexapedal machine. Nature’s quadrupeds have their own varied gait patterns which we will match up to various four-legged robot designs as well. Finally, we’ll consider bipedal machines, and we’ll take the opportunity to distinguish human-like robot bipeds that are almost foredoomed to be slow quasi-static machines from a number of less animal-like bipedal robots whose embrace of bioinspired principles allows them to be fast runners and jumpers.
Link to bibliography: https://www.coursera.org/learn/robotics-mobility/resources/pqYOc
6 videos (Total 55 min), 6 quizzes
6 videos
3.1.1 Review of kinematics7m
3.1.2 Introduction to dynamics and control15m
3.2.1 Sprawled posture runners10m
3.2.2 Quadrupeds6m
3.2.3 Bipeds9m
6 practice exercises
3.1.1 Review of kinematics (MATLAB)8m
3.1.2 Introduction to dynamics and control6m
3.2.1 Sprawled posture runners8m
3.2.2 Quadrupeds8m
3.2.3 Bipeds6m
Simply stabilized SLIP (MATLAB)12m
Week
4Composition (Programming Work)
We now introduce the concept of dynamical composition, reviewing two types: a composition in time that we term “sequential”; and composition in space that we call “parallel.” We’ll put a bit more focus into that last concept, parallel composition and review what has been done historically, and what can be guaranteed mathematically when the simple templates of week 2 are tasked to worked together “in parallel” on variously more complicated morphologies. The final section of this week’s lesson brings you to the horizons of research into legged mobility. We give examples of how the same composition can be anchored in different bodies, and, conversely, how the same body can be made to run using different compositions. We will conclude with a quick look at the ragged edge of what is known about transitional behaviors such as leaping.
Link to bibliography: https://www.coursera.org/learn/robotics-mobility/resources/pqYOc
10 videos (Total 75 min), 10 quizzes
10 videos
4.1.1 Sequential and Parallel Composition4m
4.2.1 Why is parallel hard?8m
(SUPPLEMENTARY) 4.2.2 SLIP as a parallel vertical hopper and rimless wheel6m
4.2.3a RHex: A Simple & Highly Mobile Biologically Inspired Hexapod Runner16m
(SUPPLEMENTARY) 4.2.3b Clocked RHex gaits11m
4.3.1 Compositions of vertical hoppers4m
4.3.2 Same composition, different bodies8m
4.3.3 Same body, different compositions4m
4.3.4 Transitions: RHex, Jerboa, and Minitaur leaping5m
10 practice exercises
4.1.1 Sequential and Parallel Composition6m
4.2.1 Why is parallel hard?6m
(SUPPLEMENTARY) 4.2.2 SLIP as a parallel composition6m
4.2.3a RHex4m
(SUPPLEMENTARY) 4.2.3b Clocked RHex gaits4m
4.3.1 Compositions of vertical hoppers10m
MATLAB: composition of vertical hoppers12m
4.3.2 Same composition, different bodies6m
4.3.3 Same body, different compositions4m
4.3.4 Transitions8m
3.8
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43%
got a tangible career benefit from this course
Top Reviews
By TM•Jun 5th 2017
The material itself is worth a few stars. Clearly lots of work has gone into making some interesting interactive matlab demos. some of the quizzes are unnecessarily confusing.
By PR•Aug 21st 2017
Very vast and intuitive course.I found all the information required to design my own legged robot ! I will try and design my own . Thank you so much !
Instructor
Daniel E. Koditschek
Professor of Electrical and Systems EngineeringSchool of Engineering and Applied Science
About University of Pennsylvania
The University of Pennsylvania (commonly referred to as Penn) is a private university, located in Philadelphia, Pennsylvania, United States. A member of the Ivy League, Penn is the fourth-oldest institution of higher education in the United States, and considers itself to be the first university in the United States with both undergraduate and graduate studies.
About the Robotics Specialization
The Introduction to Robotics Specialization introduces you to the concepts of robot flight and movement, how robots perceive their environment, and how they adjust their movements to avoid obstacles, navigate difficult terrains and accomplish complex tasks such as construction and disaster recovery. You will be exposed to real world examples of how robots have been applied in disaster situations, how they have made advances in human health care and what their future capabilities will be. The courses build towards a capstone in which you will learn how to program a robot to perform a variety of movements such as flying and grasping objects.
Frequently Asked Questions
When will I have access to the lectures and assignments?
Once you enroll for a Certificate, you’ll have access to all videos, quizzes, and programming assignments (if applicable). Peer review assignments can only be submitted and reviewed once your session has begun. If you choose to explore the course without purchasing, you may not be able to access certain assignments.
What will I get if I subscribe to this Specialization?
When you enroll in the course, you get access to all of the courses in the Specialization, and you earn a certificate when you complete the work. Your electronic Certificate will be added to your Accomplishments page - from there, you can print your Certificate or add it to your LinkedIn profile. If you only want to read and view the course content, you can audit the course for free.
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