Signal modification device for memory controlled manipulator apparatus

A digital position instruction signal modification device for a memory controlled teachable manipulator apparatus of the type comprising

• i. manipulator means for performing a predetermined series of operations in succession at predetermined positions during the operating made thereof,
• ii. means including a manipulator position detector for generating a digital position signal representing the actual position of said manipulator apparatus,
• iii. memory means for storing therein a plurality of digital position signals generated by said digital position signal generating means during the teaching mode of said manipulator apparatus as the digital position instruction signals to be used for causing said manipulator means to perform said predetermined series of operations, each of said position instruction signals being stored at a corresponding predetermined address within said memory means,
• iv. comparator means for comparing the output signal from said memory means with the output signal from said digital position signal generating means in a motion reproduction mode of said manipulator apparatus to produce an output error signal proportional to the difference between said two output signals, and
• v. manipulator apparatus driving means for driving said manipulator means in such a direction as to make said output error signal zero, thereby causing the position of said manipulator apparatus to correspond with the corresponding instruction signal, characterized in that said digital position instruction signal modification device comprises
• a. a modifying value setting means coupled to said manipulator position detector for setting a modifying value for modifying a desired digital position signal stored in said memory means,
• b. first buffer register means for storing therein said modifying value from said modifying value setting means,
• c. address setting means for setting the address in said memory means of the digital position instruction signal to be modified,
• d. second buffer register means for storing therein the output from said address setting means,
• e. third buffer register means for storing therein the digital position instruction signal read out from said memory means in response to the output signal from said address setting means,
• f. adder means for adding the modifying value from said first buffer register means to the digital position signal from said third buffer register means, thereby modifying said digital position signal,
• g. fourth buffer register means for storing therein the modified position signal and transferring the same to said memory means, and
• h. manually operable control means operative at times other than during said operating and teaching modes of said manipulator apparatus for controlling the storage of signals in said first, second, third and fourth buffer register means and for controlling the position of said manipulator apparatus at such times.