Predictive control method of a robot and related control system

A non-transitory computer readable medium having instructions stored thereon that, when executed by a microprocessor unit, cause the microprocessor unit to perform operations comprising:

• detecting a position of a human operator's body or of his hands in distinct sectors of a work space;
• storing in an orderly way first identifying data of occupied sectors of the work space occupied successively by the human operator while executing a task, and second identification data of respective permanence times in said occupied sectors of the work space, said first data stored in an orderly way defining a succession of work sectors progressively occupied by the human operator;
• calculating, at each step of said sequence, a respective first probability distribution P(Ak+1=a|Ak−i=ki) of transition of the human operator in a generic first sector “a” of the work space, coming from a second sector “ki” of the work space previously occupied a number “i” of steps backward in said succession from a generic third sector “k0” currently occupied;
• estimating, at each step of said sequence, a respective second probability distribution P(Ak+1=a|Ak=k0, . . . , Ak−n=kn) of transition of said human operator in said first sector “a” coming from the third sector “k0” currently occupied, conditioned by a fact that at previous steps from 1 to n of said succession the human operator occupied the work sectors k1, . . . , kn, respectively, as a linear combination of the probability distributions P(Ak+1=a|Ak−i=ki) of transition estimated at each step of said sequence, weighed with respective real positive parameters λi determined so that
• ∑
• i
• =
• 0
• n
• λ
• i
• =
• 1
• ;
• estimating a probability distribution of occupation {circumflex over (X)}k+1 of said generic first sector “a” coming from said generic third sector “k0” currently occupied, as a function of said second probability distribution P(Ak+1=a|Ak=k0, . . . , Ak−n=kn) of transition;
• determining values λi of said parameters so as to minimize a standard deviation between said probability distribution of occupation {circumflex over (X)}k+1 and an effective probability distribution of occupation Xk+1 detected by said succession of work sectors progressively occupied by the human operator;
• estimating, on a basis of said stored permanence times, a future time of arrival of the human operator from the currently occupied third sector “k0” in said first sector “a”;
• controlling a robot upon said estimated probability distribution and said estimated time of arrival, so as to move the robot in said first sector “a” synchronously with the human operator's transition to said first sector “a”.

A control system of at least one collaborative robot with a human operator, comprising:

• detection devices configured to detect a body position of the human operator or of his hands while the human operator moves in a work space,
• a memory, and
• a microprocessor control unit configured to process data stored in the memory and to control movements of a collaborative robot,
• wherein said memory has instructions stored thereon that, when executed by said microprocessor control unit, cause said microprocessor control unit to control the movements of a collaborative robot by performing operations comprising:
• detecting a position of the operator's body or of his hands in distinct sectors of said work space;
• storing in an orderly way first identifying data of occupied sectors of the work space occupied successively by the human operator while executing a task, and second identification data of respective permanence times in said occupied sectors of the work space, said first data stored in an orderly way defining a succession of work sectors progressively occupied by the human operator;
• calculating, at each step of said sequence, a respective first probability distribution P(Ak+1=a|Ak−i=ki) of transition of the human operator in a generic first sector “a” of the work space, coming from a second sector “ki” of the work space previously occupied a number “i” of steps backward in said succession from a generic third sector “k0” currently occupied;
• estimating, at each step of said sequence, a respective second probability distribution P(Ak+1=a|Ak=k0, . . . , Ak−n=kn) of transition of said human operator in said first sector “a” coming from the third sector “k0” currently occupied, conditioned by a fact that at previous steps from 1 to n of said succession the human operator occupied the work sectors k1, . . . , kn, respectively, as a linear combination of the probability distributions P(Ak+1=a|Ak−i=ki) of transition estimated at each step of said sequence, weighed with respective real positive parameters λi determined so that
• ∑
• i
• =
• 0
• n
• λ
• i
• =
• 1
• ;
• estimating a probability distribution of occupation {circumflex over (X)}k+1 of said generic first sector “a” coming from said generic third sector “k0” currently occupied, as a function of said second probability distribution P(Ak+1=a|Ak=k0, . . . , Ak−n=kn) of transition;
• determining values λi of said parameters so as to minimize a standard deviation between said probability distribution of occupation {circumflex over (X)}k+1 and an effective probability distribution of occupation Xk+1 detected by said succession of work sectors progressively occupied by the human operator;
• estimating, on a basis of said stored permanence times, a future time of arrival of the human operator from the currently occupied third sector “k0” in said first sector “a”;
• and
• controlling a robot upon said estimated probability distribution and said estimated time of arrival, so as to move the robot in said first sector “a” synchronously with the human operator's transition to said first sector “a”.