Answers :

1. The two instructions in the "programming language" of the 2011 HW would be the most difficult for robots to follow are:

a. Step-7 : In order to rotate the pencil, the robot will have to balance two conflicting tasks. While it will have to loosen the grip on the pencil to make the rotation possible, it will at the same time, have to apply enough force for the pencil not to slip and fall down. The robotic fingers with smooth surfaces (unlike flexible flesh) and lack of sensors will find it very tough.

b. Step- 13: This step involves manipulation of at least 6 degrees of freedom in the 3 fingers and at least one degree of freedom at the wrist. This needs to take place under the constraints of the given image/character that is to be drawn with the additional constraint of controlling the pressure applied on the paper. These constraints along with the fewer number of degrees of freedom are what make this step difficult.

2. A robot that can pick up a pen following the learning paradigm as in Kalakrishnan certainly displays a number of implicit characteristics in the execution of the task. The learnt force control policy is implicit in nature. This is substantiated by the observation (by Kalakrishnan et al.) that a replay of a successful Cartesian position trajectory does not necessarily result in success. The more explicit aspects would involve the knowledge of the pen being in the grasp. This is so because the pen stays in grasp if the joint angles are above a certain threshold.

The “chunking” in the structures can be the different possible force patterns at the joints.

3. Human learning may also follow the reward based process. Specifically in the context of the expert fire-fighter, he/she may store certain reward cues in his/her long term memory linked to which may be various concepts related to fire-fighting. So, for example, he/she may see the fire take a certain pattern after he/she sprays the initial jet of water. This pattern could act as a cue which would prompt the fire-fighter to take a certain action as his next step. All these processes may take place so fast that it may seem as if the fire-fighter ‘intuitively’ knows the strategy to follow.