3. The Dorben Foundry uses an overhead crane with a magnetic head to load scrap iron into the blast furnace. The crane operator uses various levers to control the three degrees of freedom needed for the crane and its magnetic head. A control is used to activate/deactivate the magnetic pull of the head. The operator is above the operation and looking down much of the time. Operators frequently complain of back pain. a. Design an appropriate control system for the crane operator. Indicate the num- ber of controls needed, their location (especially in reference to the operator's line of sight), their direction of movement, and their type of feedback. b. Indicate an appropriate control-response ratio for these controls. c. What other factors may be important in designing these controls? Lever Throw Distance (in) Crane Movement (ft) ABCD 2222 10 22840 Time to Target(s) 1.2 2.2 1.8 1.2