Robotics: Robotics


“A robot is a reprogrammable, multifunctional manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks.” (Robot Institute of America): “A robot is a reprogrammable, multifunctional manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks.” (Robot Institute of America) Definition: Alternate definition: “A robot is a one-armed, blind idiot with limited memory and which cannot speak, see, or hear.”


Ideal Tasks: Ideal Tasks Tasks which are: Dangerous Space exploration chemical spill cleanup disarming bombs disaster cleanup Boring and/or repetitive Welding car frames part pick and place manufacturing parts. High precision or high speed Electronics testing Surgery precision machining.


Automation vs. robots: Automation vs. robots Automation –Machinery designed to carry out a specific task Bottling machine Dishwasher Paint sprayer Robots – machinery designed to carry out a variety of tasks Pick and place arms Mobile robots Computer Numerical Control machines


Types of robots: Types of robots Pick and place Moves items between points Continuous path control Moves along a programmable path Sensory Employs sensors for feedback


Pick and Place: Pick and Place Moves items from one point to another Does not need to follow a specific path between points Uses include loading and unloading machines, placing components on circuit boards, and moving parts off conveyor belts.


Continuous path control: Continuous path control Moves along a specific path Uses include welding, cutting, machining parts.


Sensory: Sensory Uses sensors for feedback. Closed-loop robots use sensors in conjunction with actuators to gain higher accuracy – servo motors. Uses include mobile robotics, telepresence, search and rescue, pick and place with machine vision.


Measures of performance: Measures of performance Working volume The space within which the robot operates. Larger volume costs more but can increase the capabilities of a robot Speed and acceleration Faster speed often reduces resolution or increases cost Varies depending on position, load. Speed can be limited by the task the robot performs (welding, cutting) Resolution Often a speed tradeoff The smallest step the robot can take


Slide10: Accuracy The difference between the actual position of the robot and the programmed position Repeatability Will the robot always return to the same point under the same control conditions? Increased cost Varies depending on position, load Performance (cont.)


Slide11: Control Open loop, i.e., no feedback, deterministic Closed loop, i.e., feedback, maybe a sense of touch and/or vision


Kinematics and dynamics: Kinematics and dynamics


Kinematics and dynamics (cont.): Kinematics and dynamics (cont.)


Kinematics and dynamics (cont.): Kinematics and dynamics (cont.)


Transformations: Transformations


Dynamics: Dynamics


A 2-D “binary” robot segment: A 2-D “binary” robot segment


Problems: Problems


Control and programming : Control and programming


Control and programming (cont.): Control and programming (cont.)


Control and programming (cont.): Control and programming (cont.)


Control and programming (cont.): Control and programming (cont.)


Control and programming (cont.): Control and programming (cont.)


Feedback control: Feedback control Rotation encoders Cameras Pressure sensors Temperature sensors Limit switches Optical sensors Sonar


Slide25: New directions Haptics--tactile sensing Other kinematic mechanisms, e.g. snake motion Robots that can learn