Compensating Robot Movement Deviations
AssigneeABB Schweiz AG
InventorStig MOBERG
Life of this patent
Estimating the term…
Abstract
A method, device, and computer program product for compensating robot movement deviations caused by a gear box as well as to a robot arrangement including such a device. The device has a drift estimating block configured to obtain motor data ({dot over (q)}r) and motor torque data (τ) related to the motor, determine a measure of the temperature of the gear box based on the motor data ({dot over (q)}r) and motor torque data (τ) and estimate the drift (Δq) based on a drift value of the robot section, the drift value in turn being obtained based on the gearbox temperature measure and a gravitational torque (τgrav) of the motor, and a drift adjusting block (44) configured to adjust a control value (qr) used to control the positioning of the robot based on the estimated drift (Δq).
Claims17
A method for compensating robot movement deviations caused by a gear box connected between a robot section and a motor controlling the movement of the robot section, the method comprising the steps of:
- obtaining motor data ({dot over (q)}r) of the motor;
- obtaining motor torque data (τ);
- determining a measure (TM) of the temperature of the gear box based on the motor data ({dot over (q)}r) and motor torque data (τ);
- estimating the drift (Δq) based on a drift value (DV) of the robot section, said drift value in turn being obtained based on the gearbox temperature measure (TM) and a gravitational torque (τgrav) of the motor;
- and
- adjusting a control value (qr) used to control the positioning of the robot based on the estimated drift (Δq).
A device for compensating robot movement deviations caused by a gear box connected between a robot section and a motor controlling the movement of the robot section, the device comprising:
- at least one drift estimating block configured to
- obtain motor data ({dot over (q)}r) of the motor;
- obtain motor torque data (τ);
- determine a measure (TM) of the temperature of the gear box based on the motor data ({dot over (q)}r) and motor torque data (τ);
- estimate the drift (Δq) based on a drift value (DV) of the robot section, said drift value in turn being obtained based on the gearbox temperature measure (TM) and a gravitational torque (τgrav) of the motor;
- and
- a drift adjusting block configured to adjust a control value used to control he positioning of the robot based on the estimated drift (Δq).
The device according to claim 14, wherein there is a further drift estimating block without sign determining element and an adding unit for adding the drift values from the two drift estimating blocks in order to obtain the estimated drift.
A robot arrangement comprising an industrial robot and a device for compensating robot movement deviations,
- the industrial robot including
- a number of moveable arm sections,
- at least one motor for moving a corresponding arm section, and
- a gear box between the motor and the arm section,
- the device for compensating robot movement deviations including
- a drift estimating block and drift adjusting block having
- a temperature measure handling element configured to obtain the drift value (DV) by applying the temperature measure and gravitational torque on known relationships between drift value, temperature measure and gravitational torque.
A computer program product for compensating robot movement deviations caused by a gear box connected between a robot section and a motor controlling the movement of the robot section, the computer program product comprising a data carrier with computer program code which when run in a device for compensating robot movement deviations, causes the device to:
- obtain motor data ({dot over (q)}r) of the motor;
- obtain motor torque data (τ);
- determine a measure (TM) of the temperature of the gear box based on the motor data ({dot over (q)}r) and motor torque data (τ);
- estimate the drift (Δq) based on a drift value (DV) of the robot section, said drift value in turn being obtained based on the gearbox temperature measure (TM) and a gravitational torque (τgrav) of the motor;
- and
- adjust a control value (qr) used to control the positioning of the robot based on the estimated drift (Δq).
Dependencies are inferred from the claim text.