Answers Re-exam DD2410 2022 PDF

Question 1: Which of the following describe (a) valid algorithm(s) for numerically calculating the inverse kinematics of a manipulator, assuming that we have access to a DH description? Answers: A. the one with 𝑢𝑛𝑡𝑖𝑙 |ε | < 𝑑𝑒𝑠𝑖𝑟𝑒𝑑 𝑡𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒 Question 2: Given a 7 DoF (RRRRRRR) serial link manipula...

Question 1: Which of the following describe (a) valid algorithm(s) for numerically calculating the inverse kinematics of a manipulator, assuming that we have access to a DH description? Answers: A. the one with 𝑢𝑛𝑡𝑖𝑙 |ε | < 𝑑𝑒𝑠𝑖𝑟𝑒𝑑 𝑡𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒 Question 2: Given a 7 DoF (RRRRRRR) serial link manipulator, which of the following pairs of quantities should we expect to be able to control independently? Answers: Translational and angular velocity of the end effector. Question 3: Mark the following statements regarding manipulator kinematics as either true or false. Answers: For a serial link manipulator, we can always formulate a closed form for the forward kinematics if the DH parameters are known. For a serial link manipulator, we can always formulate a numerical approximation for the forward kinematics if the DH parameters are known. For a serial link manipulator, we can always formulate a numerical approximation for the inverse kinematics if the DH parameters are known. Question 4: Mark the following statements regarding manipulator dynamics as generally true or false. Answers: For a serial link manipulator, we can always formulate a numerical approximation for the inverse kinematics if the DH parameters are known. The joint torques necessary to generate a particular acceleration of the end effector depend on the current configuration of the robot. Question 5: What is the maximum number of controllable degrees of freedom for the end effector pose for a 7 DoF robot? Answers: With prismatic joints (PPPPPPP): 3. With revolute joints (RRRRRRR): 6. Question 6: Mark all statements as generally true or false with regard to manipulator Jacobians. Answers: The Jacobian determines the relationship between joint velocities and end-effector velocities in task space. The Jacobian transpose relates joint torques to end-effector wrenches. Question 7: Which of the following joint actuation options will give us the highest precision for positioning an end effector? Order from highest to lowest precision. Answers: Brushless DC motor and optical encoder > A stepper motor in direct drive configuration > Permanent magnet DC motor and a potentiometer > Pneumatic cylinder with a strain gauge air pressure sensor. Question 8: Match the grasp types from the list with the appropriate task. Answers: Picking up trash: Caging grasp. Picking up greased parts: Form closure. Adjusting cylindrical beverage cans: Force closure. Question 9: Rate the following statements about manipulator control as either true or false. Answers: Independent joint PID control is robust to modeling errors. Given good kinematic and dynamic models of a manipulator, it is possible to implement end-effector force control using only sensors placed in the joints. Question 10: Order the following quantities by computational expense, from less expensive to more expensive. Answers: Forward kinematics < Jacobian calculation < Inverse kinematics (4 DoF SCARA robot) < Inverse kinematics (7 DoF manipulator, numerical). Question 11: What action will be executed if: A) The battery level is not ok? B) The battery level is ok? Answers: A) Recharge. B) Do main task. Question 12: Consider the same behavior tree as in question 11. Mark all statements as true or false. Answers: The designer can assume that the AUV is already near the charger when designing "Dock with charger." If "Do main task" takes a long time, the AUV might pause execution to recharge its batteries. Question 13: Mark all statements as true or false. Answers: A condition has fewer return statuses than an action. For a condition node, “Failure” is interpreted as “False.” Question 14: The RRT* algorithm produces a tree structure. Mark all statements as true or false. Answers: Your vehicle must be able to traverse any edge of the tree in both directions. Question 15: Mark the following statements as either true or false. Answers: A* will terminate and inform you if no valid solution exists. Question 16: For each alternative below, mark if it is true or false, regarding a differential drive robot. Answers: Each wheel is driven by a separate motor. To drive forward, you would typically give +V voltage to one motor and -V voltage to the other motor. Question 17: When comparing a multi-rotor drone with a fixed-wing drone, which properties match a multi-rotor drone best? Answers: Vertical landing and takeoff. Can stand still in the air. High maneuverability. Question 18: Which of the following sensors are 1) proprioceptive or 2) exteroceptive? Answers: RGB-D: Exteroceptive. Gyro: Proprioceptive. Accelerometer: Proprioceptive. Radar: Exteroceptive. Question 19: Match the best-fitting statement to the steps of a localization system. Answers:  Prediction step: Position uncertainty increases. Update step: Position uncertainty decreases. Question 20: Mark each statement as true or false regarding occupancy grids. Answers: The memory requirements for a standard 3D occupancy grid scale cubically with the dimensions. Question 21: Mark each alternative as either true or false regarding a Kalman filter. Answers: State represented by a Gaussian distribution. Question 22: Loop closures are important in SLAM. Mark each statement as true or false. Answers: Proprioceptive sensors are not better suited for detecting loop closures than exteroceptive sensors. Question 23: Mark each statement regarding SLAM as either true or false. Answers: Current SLAM systems can handle environments larger than a couple of meters. Question 24: Which of the following sensors would be best to detect that a collision occurred? Answers: Accelerometer. Question 25: Mark each statement regarding exploration as either true or false. Answers: A common strategy is to move to parts of space that are at the border between free space and unknown space. Occupancy grids are often used for exploration.