This paper presents a grasp force regulation strategy for precision grasps. The strategy makes no assumptions about object properties and surface characteristics and can be used with a wide range of grippers. It has two components: a slip signal detector that computes the magnitude of slip and a grasping force set point generator that acts on the detector's output. The force set point generator is designed to ensure that slip is eliminated without using excessive force. This is particularly important in several situations like grasping fragile objects or in-hand manipulation of thin small objects. Several experiments were conducted to simulate various grasping scenarios with different objects. Results show that the strategy was very successful in dealing with uncertainty in object mass, surface characteristics, or rigidity. The strategy is also insensitive to robot motion.

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We present in this paper a ‘how-to’ frameworkfor designing motivating assessments, based upon thecognitive theories of expectancy-value and of aligned andauthentic objectives. The framework recasts thesecognitive theories into more practical steps of determiningobjectives, setting expectations, and framing theassessment to be well scoped, authentic, and relatable. Inthe Fall 2017 offering of our Introduction to MechanicalEngineering course, two new short design challenges andone long design challenge were piloted after beingdesigned according to the objectives-expectations-framingframework. In each case, the assessments were designed tobe (to varying extents) engaging/authentic (something thatstudents would want to do), and doable/relatable(something the students could do). The term long project(of largest scope, authenticity, and relatability) was foundby student survey to be the most motivating. Of the twosmaller projects, the second, while seemingly moreauthentic and relatable, was found to be less motivating.We understand this to be due to the context of thisassessment coming during a time in the term when studentwere busy with the term design project and other courses.

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