View source

You do not have permission to edit this page, for the following reason:

You can view and copy the source of this page:

Students working on the projects listed below may begin their work right away, upon approval. Students wishing to propose their own project must write a proposal of approximately 3-5 pages, with at least one drawing (hand drawing OK) showing the whole device, a paragraph or two discussing the overall function and goal of the project, as well as discussions of the sensors and actuators you will use, the computation, and the mechanical design. Although you do not have to have worked out all the details, the proposal should show that you've thought about how the whole project will work. It can be a fun whimsical project, or it can solve a practical problem. Previous projects are a good indicator of what's possible. Your proposal must also include milestones to be met during week 9. '''Your final project cannot be a robot for DC.''' Projects will be judged on functionality (does it do what it's supposed to do? does it serve a useful function?), reliability (does it do it every time?), ambitiousness (is the problem challenging? did you contribute a new capability to the wiki?), and aesthetic appeal (is it packaged nicely? is it pleasing to watch or fun to interact with?). == Recommended Projects == === Underwater Electrosense === Electrosense is a new underwater sensing technology being developed at Northwestern. The sensor's emitters generate an electric field, and detectors sense perturbations in the electric field due to objects in the environment. Robots carrying the sensor can determine their own position in a known environment, or identify objects in an unknown environment. This project will develop a new kind of electrosensor and place it on a robot moving along one linear direction (e.g., a sensor on a ball screw carriage). The sensor will generate fields at different frequencies and use the frequency-dependent response to characterize the impedance of nearby objects. The robot will scan the sensor along one degree-of-freedom to generate an "electrosense image" of the environment. '''Week 9 milestone:''' === High-speed Motor Control with Your PC === You will make motor control PICs that make it easy for anyone to do high-speed encoder-based feedback control of brushed DC motors with only a few dollars of hardware and a cable to connect to matlab on your PC. Your project will build on [[I2C Motor Controller|this project]], see also [[Granular Flow Rotating Sphere|this project]], and will consist of a "master" PIC that communicates with the PC plus any number of "slave" PICs, one for each motor to be controlled. The job of the master PIC is to take the program, written in Matlab or Processing, and communicate it to the slave PICs, and to coordinate the initiation of moves by the slave PICs, which implement PID controllers at rates up to 2 kHz. Your final project will demonstrate high-speed trajectory following by a 2-DOF parallelogram linkage that can throw and catch objects in a vertical plane. Optional: use external memory to perform data logging at each slave PIC, and send this data back to the PC upon request. '''Week 9 milestone:''' Demonstrate controlled moves by the motors following a simple program in matlab, and show a design of the parallelogram linkage. === Portable 6-DOF Vibratory Platform for Parts Manipulation === The [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm PPOD] is a 6-degree-of-freedom vibratory platform that manipulates multiple parts simultaneously. See [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/PPOD2video.mov this video], for example. You will make a small, portable version (PPOD-Lite) that uses 6 small speakers arranged with 3 acting in the horizontal plane and 3 acting vertically. It will have 6 axes of accelerometer feedback on the motion of the plate, and it will use FFTs of the accelerometer data to update the periodic speaker control signals so that the plate learns to follow the desired periodic motion profile. Desired motion profiles will be sent to the plate via a USB connection with a PC. Power for the device will come from a power adapter plugged into the wall. '''Week 9 milestone:''' Have the mechanical design completed, and be able to command analog profiles to the speakers and read in analog signals from the 6 accelerometers. === Swarm Robot === The [http://www.e-puck.org/ e-puck] is a small PIC-based mobile robot. These are being used for different research projects at Northwestern, including swarm robotics. These robots cost nearly $1000 each. For most swarm projects, though, we should be able to build a mobile robot that costs 1/10th of that, based on the more powerful PIC32. This project is to build a prototype of this "cheap puck" swarm mobile robot, including a first version of the control software. The robot will use two geared stepper motors for its wheels, xbee wireless radio communication, a light color sensor for sensing the environment, and a unique LED pattern for each robot so that an overhead vision system can recognize each robot's position and orientation. '''Week 9 milestone:''' Have the mechanical system and circuitry essentially finalized, and basic code to drive the motors and speak RS-232 over the wireless xbee. (The last week will focus on software and control system development.) === Furuta Pendulum (Inverted Pendulum) === [[Image:furutapendulum.jpg|right]] Build an inverted pendulum system to experiment with balancing control algorithms. This kind of inverted pendulum is called a Furuta pendulum. A motor controls the rotation of a horizontal beam about a stationary vertical pivot axis, and a second beam rotates freely about an axis along the horizontal beam. The goal is to take the second beam from the hanging down configuration to balanced in the up configuration. An encoder measures the angle of the second beam. The motor pumps energy into the beam, then (probably) switches to a stable linearizing controller when the beam is vertical. See [http://www.control.tfe.umu.se/Set_Ups/Furuta_Pendulum/Furuta_Pendulum_info.html this page], for example. This problem is a challenging dynamic task, and is impressive when it works. '''Week 9 milestone:''' Have the mechanical system nearly finalized, with controlled motion of the motor. The swing-up and balancing algorithms do not have to be implemented yet. === Other Educational Control System === Create an inexpensive educational control system, where students learn to develop controllers to stabilize a mechanical system. You can check out [http://www.quanser.com/english/html/challenges/fs_chall_overview.html Quanser] for ideas. A successful final project could be a prototype for future EECS 360 or EECS 374 labs or projects. An example is the Furuta pendulum, above. === Monkeybot 2 === Last year a student team built the Monkeybot, seen in this [http://www.youtube.com/watch?v=0hfwJEVQyeQ video]. It uses two electromagnets on bearings with encoders, and a DC gear motor with encoder, to locomote dynamically on a steel wall. The proposed project is to build something similar, except wireless and with only one electromagnet. This robot "flings" itself from handhold to handhold. It can also implement a control algorithm to take it from hanging straight down to balanced in the up position. '''Week 9 milestone:''' === Rolling Manipulation === Build a research apparatus for control of rolling manipulation. See [http://lims.mech.northwestern.edu/~lynch/research/videos/dynamic.html#rolling this page] for example, and this [http://lims.mech.northwestern.edu/~design/mechatronics/2006/butterfly/index.htm previous project page]. Your apparatus will be used in future research experiments in stabilization of dynamic rolling. It will likely make use of a resistive element and a conductive ball for sensing. The "butterfly" you see in the examples above is a form of "contact juggling." Check out [http://www.youtube.com/watch?v=FX7xruR12YA this video of Michael Moschen] to see other contact juggling (with the butterfly about halfway through). Check out other Michael Moschen videos on youtube to see some amazing performances! '''Week 9 milestone:''' === Ferrofluid Art === [http://www.youtube.com/watch?v=PvtUt02zVAs] <br clear=all> <!-- === Trick Shot Pool Robot === === Science Roadshow === === Marionette === Make a planar puppet actuated by strings pulled by robot arms out of view of the viewer. The robot arms could be actuated by RC servos. See this [http://robotics.mech.northwestern.edu/~murphey/PuppetSimulation_GTandCU_high.mpg video (warning! it's 33 MB)] of another automated marionette system. '''Week 8 milestone:''' Demonstrate controlled 2-DOF motion, e.g., to make the arm of the puppet wave. === Moving Fish Refuge === (Client: Prof. Malcolm MacIver.) The weakly electric knifefish often prefers to hide in tight spaces rather than to swim in the open. See [http://glacier.me.jhu.edu/Movies/fish_hand1-small.mov this video] of this fish attempting to stay hidden in a tube as it is moved back and forth. Prof. MacIver would like to build a tube that can move under computer control, at different angles (other than purely horizontally), to see what motions of the tube the fish will track. You will build a 1-DOF prismatic device that slides a tube back and forth, and design a mechanism so that the angle of the tube can be changed relative to the linear slide. '''Week 8 milestone:''' Demonstrate trajectory following of sinusoidal motions by a carriage along a linear rail using either a stepper motor or a motor and encoder. === Experiment in Nonlinear Dynamics: Ball Bouncing === You will build a classic experimental apparatus in nonlinear dynamics. The PIC controls the oscillation of a speaker in the vertical direction. A concave lens is attached to the top of the speaker, and a ball bearing bounces on the lens as the speaker moves in the vertical direction. The concavity of the lens keeps the ball centered. For some frequencies and amplitudes, the ball will bounce in a steady cycle, bouncing to approximately the same height after each impact. As you increase the amplitude, however, the ball may go through a period-two phase, where it first flies high, then low, then high, then low, etc. If you continue to increase the amplitude, you may see higher-period behavior, and finally the motion of the ball will be hard to predict or "chaotic." You will create a microphone circuit to listen for the impact between the ball and the lens, and the PIC will calculate the time between impacts and send the data back to a matlab program. The PIC will also monitor the acceleration of the speaker using an accelerometer and send that data back to the matlab program. The matlab program controls the amplitude of the speaker oscillation by communicating with the PIC. The matlab program plots the experimental results, possibly as a "bifurcation diagram." See [http://fizyka.phys.put.poznan.pl/~pieransk/BouncigBall.html this site] and [http://scitation.aip.org.turing.library.northwestern.edu/getabs/servlet/GetabsServlet?prog=normal&id=AJPIAS000054000010000939000001&idtype=cvips&gifs=yes this article] for more information on this experiment. You can also use the fact that you have a PIC microcontroller to do real-time feedback control, modulating the control signal to the speaker as a function of the duration between ball impacts. '''Week 8 milestone:''' Demonstrate successful control of the amplitude of the speaker motion, reading of the accelerometer, and bidirectional communication between the PIC and matlab. === Three-Speaker Chladni Pattern Generator === See videos on youtube of "Chladni Patterns." Now imagine making one actuated by three separate speakers spaced at 120 degrees on a round plate. Signal generator chips, controlled by the PIC, will be used to generate the input signals to the speaker amplifiers. Provide knobs to allow the user to set the vibration patterns, or switch to stored motions on the PIC. See what kinds of patterns you can create. '''Week 8 milestone:''' Demonstrate control of one speaker using a signal generator chip and analog (knob) inputs to the PIC. Show initial (traditional) Chladni patterns. === High-speed Wireless Communication === To allow two PICs, or a PIC and a PC, to communicate wirelessly, we are currently using RS-232 and the xbee 802.15.4 chips. RS-232 is an old technology, and the data rates are relatively low in this solution (250 kbps max for the xbee chips, and typically 115.2 kbps for RS-232). In this project, you will develop a new higher-speed solution based on faster SPI communication and [http://www.sparkfun.com/commerce/product_info.php?products_id=691 this wireless product]. You will demonstrate high-speed wireless communication between a PC and the PIC. You will then demonstrate the high-speed communication by some dynamic task, such as wireless teleoperation of a one-dof robot arm as it juggles a ball or balances an inverted pendulum. '''Week 8 milestone:''' Demonstrate high-speed wireless communication and finalize the mechanical details of the dynamic task. --> === Other Ideas === * Claude Shannon, known as the "Father of Information Theory," made a bounce juggling machine many years ago, perhaps the first to make a real juggling machine. It uses no sensor feedback. See the video at [http://www.youtube.com/watch?v=sBHGzRxfeJY]. Can you build something similar? * This would make a great demo if you had a dog! See [http://www.youtube.com/watch?v=4PcL6-mjRNk]. * Build a 2-DOF pizza manipulator. See [http://www-hh.mech.eng.osaka-u.ac.jp/robotics/pizzae.html]. == Class Selections == The * indicates that a proposal is due. * Team 11: Rolling Manipulation * Team 12: Furuta Pendulum * Team 13: Ferrofluid Art * Team 14: Swarmbot * Team 15*: Remote-controlled Guitar * Team 21: Music Suit * Team 22: Pantograph Haptics * Team 23: High Speed Motor Control * Team 24: 6-DOF Shaker Table * Team 25: Conservation of Momentum Locomotion * Team 26: Electrosense * Team 27*: Fridge Can Launcher <!-- From 2008: === Experiment in Granular Flows === (Client: Prof. Rich Lueptow.) You will build a device to support experiments studying how grains separate or mix under forcing. The device consists of a sphere partly filled with granular matter that is rotated about two orthogonal axes by independent motors under PIC control. The user sends the desired motion profile via the "serial" interface in Matlab, and the PIC interprets it and executes it. Upon successful completion, the PIC signals the Matlab program that the motion is complete. To get an idea of what the actuation might look like, check out the [http://www.mech.northwestern.edu/courses/433/2005/projects/servosphere/index.htm servosphere] from ME 433 Advanced Mechatronics in 2005. The sphere must be releasable. Maximum speed of the sphere is 60 RPM, and its diameter is approximately 20 cm. === Vibratory Clock === You will build a horizontal circular platform that is actuated from underneath by three compliantly-attached voice coil actuators (i.e., speakers). The vibration of the platform causes an hour "hand" on top of the platform to slide around the circular platform, impelled by friction forces due to the vibration. If you bump the hand away, it slowly moves back to the correct hour. You may find other imaginative uses for your device. Check out [http://lims.mech.northwestern.edu/projects/frictioninducedforcefields/index.htm this website] to see more information on how this works and some videos of parts moving around a vibrated plate. === Light-gradient Detecting Mobile Robot === You will build a mobile robot with three tri-color light sensors. The purpose of this robot is to track moving colors projected by a ceiling-mounted LCD projector pointing downward. By calculating the color gradient, the robot can move to the region of maximum redness, blueness, or greenness, for example. It is a model of a robot attempting to find the source of an oil spill, or the center of a chemical plume. === Vibration Suppression === You will build an active vibration-suppression system. It will consist of a mass attached to a wall by a spring and moving on a linear slide, and attached on the other side to an ordinary audio speaker. You will mount an accelerometer on the mass, and, based on that signal, actuate the speaker to try to damp the mass's vibration as quickly as possible. Demonstration will include showing the accelerometer signal on an oscilloscope (or collected in Matlab) when control is off and when control is on. Another good challenge is to develop a controller that makes the mass move along an arbitrary periodic motion; your controller must "learn" to apply the right periodic control signal to make the mass follow the desired periodic motion. The desired and actual motion can be displayed on an oscilloscope or a Matlab program. === Wii-like Mouse Control === You will build a wireless hand-held device that uses accelerometers to sense the motion of the device and translates it into the motion of a cursor on a PC screen. The device could use a single 2-axis accelerometer, or you may have other ideas. One challenge is to translate the accelerometer signals into easily-controllable but dynamic motions of the cursor. (Not just simple tilt-sensing and slow cursor motion.) Should you have a dead-band where the cursor doesn't move at all if the acceleration doesn't exceed some threshold, similar to picking up a mechanical mouse and moving it back to the center of the mousepad? Or a button indicating "keep cursor stationary?" You will need plenty of time to work on user interface issues once the basic device is built. Success of the project in the final demo will be determined by how easily a new user can quickly and accurately control the mouse (e.g., to move to desired points on the screen). You may have other ideas how to use it. Can you flip pages in a virtual book? Two other possible challenges: Can you hack a wireless mouse so that you are actually using a mouse bluetooth wireless interface? Or, if you are simply interacting with a Matlab program with the "serial" routines, can you put a pager motor in the device to indicate when you are moving on a "rough patch" on the screen? === Programmable-Stiffness Joint === Muscles behave in part like variable-stiffness springs. There are also several muscles crossing most joints, providing a degree of redundancy. One way we can use this redundancy is to control the joint's position and stiffness simultaneously (without using high-bandwidth feedback control to achieve the desired stiffness, as is necessary with a typical robot joint). Or to control the joint torque and stiffness simultaneously. In this project you will create a single joint controlled by two nonlinear springs actuated by two independent motors to achieve simultaneous controllable endpoint stiffness and position, and demonstrate its controlled motion along desired trajectories. -->

Return to ME 333 Suggested Final Projects.