Industrial robot with servo system

A robot device comprising:

• a base,
• a plurality of mechanical members connected successively to each other to said base, including a first one of said members at a first end of said plurality of members connected to said base and a second one of said members at the other end of said plurality of members from said first member, each successive adjacent pair of said members and base having a respective relative motion therebetween, and said second member having a near end connected to the respective adjacent one of said plurality of members and a far end opposite said near end,
• a plurality of mechanical power sources selectively mounted on said base and members, each said mechanical power source controlling said respective relative motion of a respective adjacent pair of said base and members,
• a plurality of indicator means distributed on said members and base for allowing determination of incremental changes in the relative positions of said adjacent pairs of base and members during each of a repeated predetermined interval, corresponding to the respective ones of said relative motions, and
• control means for controlling each said source of mechanical power for moving said far end of said second member along a trace from an initial position to a working position without coming to a halt between said initial and working positions,
• wherein:
• said trace is nonlinear:
• said control means operates to determine said trace based on preset operational data, said preset operational data including the coordinates, in a respective coordinate system, of said initial and working positions, coordinates of further points for characterizing at least in part the path of said trace between said initial and working positions, at least one speed variation pattern which takes into account acceleration and deceleration characteristics of said plurality of members with said mechanical power sources and indicator means;
• and
• said control means operates repeatedly at each said predetermined interval to determine 1) the location of said far end of said second member based on inputs from said indicator means indicating each of said incremental changes during the preceding interval, 2) information corresponding to the desired speed and direction of the motion of said far end of said second arm for the next interval, including components of velocity with respect to said coordinate system for the motion of said far end of said second arm along said trace, based on each said speed variation pattern, and 3) corresponding signals to be supplied simultaneously during the next interval to said mechanical power sources for driving respective ones of said mechanical power sources at respective rates of change of the corresponding ones of said relative positions to move said far end of said second member along said trace;
• and
• each said speed variation pattern comprising data specifying desired values of said respective ones of said velocity components in said coordinate system as a function of respective relative position values of said adjacent pairs of base and members, each said speed variation pattern having nonlinearly rising and falling parts, said far end of said second arm accordingly moving over said trace with smooth transitions of speed and direction;
• said far end of said second member is moved at constant speed along said trace, except while it is in an acceleration zone of said trace which starts at said initial position and a deceleration zone which ends at said working position,
• said far end of said second member moves linearly in at least a portion of each of said acceleration and deceleration zones based on corresponding data included in said operational data, and
• each said linear part of each said acceleration or deceleration zone corresponds to a respective portion of one of said rising or falling parts of a respective one of said at least one speed variation pattern;
• said plurality of said mechanical members further comprising a third one of said members, said first member having a near end connected to said base and a far end opposite said near end thereof, said third member having a near end connected to said far end of said first member and a far end connected to said near end of said second member,
• said first member being connected at said near end thereof to said base to rotate in a horizontal plane about a vertical axis extending through said base,
• said third member being connected to said first member to rotate in a horizontal plane about a second vertical axis,
• said second member being oriented vertically and connected at said near end thereof to said far end of said third member so that said far end of said second member can be moved vertically with respect to said far end of said third member,
• the respective one of said mechanical power means for controlling the rate of change of said relative motion between said base and said first member being a first servo motor mounted on said base,
• the respective one of said mechanical power means for controlling the rate of change of said relative motion between said first and third members being a second servo motor mounted on said first member,
• the respective one of said mechanical power means for controlling the rate of change of said relative motion between said third and second members being a third servo motor mounted on said third member,
• said control means including servo control circuits for said first, second and third servo motors;
• and
• said trace includes two curved segments respectively adjacent said linear portions of said acceleration and deceleration zones and a linear segment between said two curved segments.

A robot device comprising:

• a base,
• a plurality of mechanical members connected successively to each other and to said base, including a first one of said members at a first end of said plurality of members connected to said base and a second one of said members at the other end of said plurality of members from said first member, each successive adjacent pair of said members and base having a respective relative motion therebetween, and said second member having a near end connected to the respective adjacent one of said plurality of members and a far end opposite said near end,
• a plurality of mechanical power sources selectively mounted on said base and members, each said mechanical power source controlling said respective relative motion of a respective adjacent pair of said base and members,
• a plurality of indicator means distributed on said members and base for allowing determination of incremental changes in the relative positions of said adjacent pairs of base and members during each of a repeated predetermined interval, corresponding to the respective ones of said relative motions, and
• control means for controlling each said source of mechanical power for moving said far end of said second member along a trace from an initial position to a working position without coming to a halt between said initial and working positions,
• wherein:
• said trace is nonlinear;
• said control means operates to determine said trace based on preset operational data, said preset operational data including the coordinates, in a respective coordinate system, of said initial and working positions, coordinates of further points for characterizing at least in part the path of said trace between said initial and working positions, and at least one speed variation pattern which takes into account acceleration and deceleration characteristics of said plurality of members with said mechanical power sources and indicator means;
• and
• said control means operates repeatedly at each said predetermined interval to determine 1) the location of said far end of said second member based on inputs from said indicator means indicating each one of said incremental changes during the preceding interval, 2) information corresponding to the desired speed and direction of the motion of said far end of said second arm for the next interval, including components of velocity with respect to said coordinate system for the motion of said far end of said second arm along said trace, based on each said speed variation pattern, and 3) corresponding signals to be supplied simultaneously during the next interval to said mechanical power sources for driving respective ones of said mechanical power sources at respective rates of change of the corresponding ones of said relative positions to move said far end of said second member along said trace;
• and
• each said speed variation pattern comprising data specifying desired values of said respective ones of said velocity components in said coordinate system as a function of respective relative position values of said adjacent pairs of base and members, each said speed variation pattern having non-linearly rising and falling parts, said far end of said second arm accordingly moving over said trace with smooth transitions of speed and direction;
• said operational data includes a plurality of said speed variation patterns, and
• said determining of said velocity components of said far end of said second arm in said coordinate system in each said interval is according to each respective one of said speed variation patterns;
• said trace is controlled by said control means to include an acceleration zone in the beginning part of said trace adjacent said initial position and a deceleration zone in the ending part of said trace adjacent said working position,
• said far end of said second member moves linearly in at least a portion of each of said acceleration and deceleration zones based on corresponding data includes in said operational data, and
• each said linear part of each said acceleration or deceleration zone corresponds to a respective portion of one of said rising or falling parts of a respective one of said at least one speed variation pattern;
• said plurality of said mechanical members further comprising a third one of said members, said first member having a near end connected to said base and a far end opposite said near end thereof, said third member having a near end connected to said far end of said first member and a far end connected to said near end of said second member,
• said first member being connected at said near end thereof to said base to rotate in a horizontal plane about a vertical axis extending through said base,
• said third member being connected to said first member to rotate in a horizontal plane about a second vertical axis,
• said second member being oriented vertically and connected at said near end thereof to said far end of said third member so that said far end of said second member can be moved vertically with respect to said far end of said third member,
• the respective one of said mechanical power means for controlling the rate of change of said relative motion between said base and said first member being a first servo motor mounted on said base,
• the respective one of said mechanical power means for controlling the rate of change of said relative motion between said first and third members being a second servo motor mounted on said first member,
• the respective one of said mechanical power means for controlling the rate of change of said relative motion between said third and second members being a third servo motor mounted on said third member,
• said control means including servo control circuits for said first, second and third servo motors;
• each said servo control circuit is provided from the respective one of said indicator means during each said interval with a respective feedback which corresponds to the rate of change of the corresponding relative position during the preceding interval;
• each said speed variation pattern rises smoothly and non-linearly from zero to a respective maximum constant value and subsequently falls smoothly and non-linearly to zero;
• said speed variation patterns include respective ones for x- and z-axes of said coordinate system;
• said z-axis is vertical and said x-axis is horizontal,
• said linear portions of said trace corresponding to said acceleration and deceleration zones are oriented vertically;
• and
• said trace includes two curved segments respectively adjacent said linear portions of said acceleration and deceleration zones and a linear segment between said two curved segments.