System for motion control, method of using the system for motion control, and computer readable instructions for use with the system for motion control
View Patent ↗A motion control system and method that includes a central controller configured to generate first and second demand control signals to be used to define actuation motion of respective first and second actuators. The central controller is in communication with first and second nodes by way of a data network, each node including at least a respective actuator configured to implement at an actuator time a motion or force-related effort based upon the respective demand control signal. Each node also includes a memory configured to store at least one respective propagation delay parameter related to a signal propagation delay between the central controller and the node. A timing mechanism establishes timing at each node based on the respective propagation delay parameter so that the actuator time at the nodes occurs simultaneously. Strictly cyclic and/or full-duplex high-speed communication can be supported. The network can be wired in a ring or as a tree and with twisted pair cabling or fiber. The central controller issues demand signals to the nodes that are actuator, servo motor drive, and/or I/O devices. The central controller can also provide a timing message that is used by the nodes, in conjunction with local delay correction circuitry, so that the simultaneous acquisition of data and the simultaneous implementation of controlled action occur.
1. A slave configured to be in communication during operation with a central controller over a full-duplex data network, said slave comprising:
a first receiver configured to receive a first signal transmitted along a first direction over said data network;
a second receiver configured to receive a second signal transmitted along a second direction over said data network;
an actuator configured to implement an action based one of said received first signal and said second signal;
a timing operation mechanism configured to establish timing at the slave, based on a propagation delay parameter between the slave and the central controller, and to delay reception of a servo clock message by an amount of time corresponding to the propagation delay signal for information passed between the slave and the central controller so that an actuation time at the slave occur simultaneously;
a first reply transmitter configured to answer said first signal in said second direction;
a second reply transmitter configured to answer said second signal in said first direction;
a selector configured to select said first reply transmitter when said first signal is received and said second reply transmitter when said second signal is received; and
a delay correction memory configured to store a forward path delay correction signal and a reverse path delay correction signal, wherein
said actuator is configured to implement said motion or force-related effort at an actuator time based upon a selected one of said forward path delay correction signal and said reverse path delay correction signal, and
said selector also is configured to select said forward path delay correction signal when said first signal is received and said reverse path delay correction signal when said second signal is received.