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US 10,935,954 B2Granted
Motion system health management using existing servo drive variables
AssigneeArcus Technology, Inc.
InventorChristopher C. Chang
Life of this patent
Estimating the term…
Abstract
A motion system and method of managing health of the motion system uses exclusively motion variables used by a servo drive of the motion system to calculate at least one health indication value for the motion system. The health indication value is used to generate a notification for maintenance of the motion system.
Claims12
A method of managing health of a motion system with a servo drive, the method comprising:
- driving a motor of the motion system using the servo drive to perform a sequence of motions to build a three-dimensional torque model;
- as the motor is being driven, for each motion, collecting a current I that is used to drive the motor, a position P of the motor and a velocity V of the motor together at the same time to produce multiple sets of current I, position P and velocity V values;
- for each set of current I, position P and velocity V values, computing a corresponding torque value using an equation T=Kt*I, where T is a torque value, Kt is a torque constant and I is a driving current;
- building the three-dimensional torque model for the motion system using the position P, velocity V and corresponding torque values, the three-dimensional torque model being a three-dimensional model in space defined by position, velocity and torque;
- after the three-dimensional torque model has been built, collecting motion variables that are used by the servo drive to drive the motor of the motion system in response to motion commands, the motion variables including an actual current I to drive the motor, an actual position P of the motor and an actual velocity of the motor;
- calculating a health indication value for the motion system exclusively using the collected motion variables, wherein calculating the health indication value comprises:
- computing an actual torque value using the actual current I;
- and
- taking a difference between the actual torque value and a torque value from the three-dimensional torque model to derive a torque deviation value that is used as the health indication values, wherein the torque value from the three-dimensional torque model is selected using the actual position P and the actual velocity V;
- and
- in response to the health indication value, generating a notification for maintenance of the motion system.
8 more elements
A motion system comprising:
- a motor, and
- a servo drive configured to drive the motor, the servo drive including, memory;
- and
- at least one processor configured to:
- drive the motor of the motion system to perform a sequence of motions to build a three-dimensional torque model;
- as the motor is being driven, for each motion, collect a current I that is used to drive the motor, a position P of the motor and a velocity V of the motor together at the same time to produce multiple sets of current I, position P and velocity V values;
- for each set of current I, position P and velocity V values, compute a corresponding torque value using an equation T=Kt*I, where T is a torque value, Kt is a torque constant and I is a driving current;
- build the three-dimensional torque model for the motion system using the position P, velocity V and corresponding torque values, the three-dimensional torque model being a three-dimensional model in space defined by position, velocity and torque;
- after the three-dimensional torque model has been built, collect motion variables that are used by the servo drive to drive the motor of the motion system in response to motion commands, the motion variables including an actual current I to drive the motor, an actual position P of the motor and an actual velocity of the motor;
- calculate a health indication value for the motion system exclusively using the collected motion variables, wherein calculating the health indication value comprises:
- computing an actual torque value using the actual current I;
- and
- taking a difference between the actual torque value and a torque value from the three-dimensional torque model to derive a torque deviation value that is used as the health indication values, wherein the torque value from the three-dimensional torque model is selected using the actual position P and the actual velocity V;
- and
- in response to the health indication value, generate a notification for maintenance of the motion system.
12 more elements
Dependencies are inferred from the claim text.