Method and apparatus for temperature characterization in welding

A system for controlling heating of a workpiece, comprising:

• an interface configured to receive a target temperature (TT) for the workpiece;
• at least one computer configured to:
• select a current temperature (TS) for the workpiece based on monitoring one or more temperature sensors;
• and
• set a control temperature (TC) based on a received target temperature (TT) and the selected current temperature (TS);
• and
• control heating of the workpiece via an induction heater until the workpiece reaches the control temperature (TC) as measured by at least one of the one or more temperature sensors, and control the induction heater to stop heating the workpiece in response to the workpiece reaching the control temperature (TC);
• wherein the at least one computer is configured to
• characterize a temperature ramp rate based on a measured temperature overshoot at the workpiece when the induction heater is off,
• determine an interim temperature (TI) based on the temperature ramp rate at an expiration of a timer;
• control heating of the workpiece to the interim temperature (TI) by controlling the induction heater;
• and
• control heating of the workpiece from the interim temperature (TI) to the received target temperature (TT) by controlling the induction heater based on the temperature ramp rate.

A system for controlling heating of a workpiece, comprising:

• an interface configured to receive a target temperature (TT) for the workpiece;
• at least one computer configured to:
• select a current temperature (TS) for the workpiece based on monitoring one or more temperature sensors;
• and
• set a control temperature (TC) based on a received target temperature (TT) and the selected current temperature (TS);
• monitor the outputs of the one or more temperature sensors at an expiration of a first time timer;
• and
• control heating of the workpiece via an induction heater until the workpiece reaches the control temperature (TC) as measured by at least one of the one or more temperature sensors, and control the induction heater to stop heating the workpiece in response to the workpiece reaching the control temperature (TC);
• wherein the at least one computer is configured to
• characterize a temperature ramp rate based on a measured temperature overshoot at the workpiece when the induction heater is off,
• control updating an interim temperature (TI) based on the temperature ramp rate at an expiration of a second timer, wherein the at least one computer is configured to heat the workpiece to the interim temperature (TI);
• and
• control heating of the workpiece from the interim temperature (TI) to the received target temperature (TT) by controlling the induction heater based on the temperature ramp rate.

A system for controlling heating of a workpiece, comprising:

• an interface configured to receive a target temperature (TT) for the workpiece;
• a processor configured to:
• select a current temperature (TS) for the workpiece based on monitoring one or more temperature sensors;
• and
• set a control temperature (TC) based on a received target temperature (TT) and the selected current temperature (TS);
• and
• a controller configured to:
• control heating of the workpiece via a heater until the workpiece reaches the control temperature (TC) as measured by at least one of the one or more temperature sensors, and control the heater to stop heating the workpiece in response to the workpiece reaching the control temperature (TC);
• wherein:
• the processor is configured to characterize a temperature ramp rate based on a measured temperature overshoot at the workpiece when the heater is off, and
• the controller is configured to control heating of the workpiece to the received target temperature (TT) by controlling the heater based on the temperature ramp rate, and
• wherein, when the received target temperature TT) is greater than a current highest temperature (TH) by at least a first number of degrees Centigrade, the processor is configured to set the control temperature (TC) to:
• TC=TH+m*(TT−TH), where ‘m’ is less than or equal to 1 and greater than or equal to 0, and
• when the received target temperature (TT) is not greater than the current highest temperature (TH) by at least the first number of degrees Centigrade, setting the control temperature (TC) to equal the received target temperature (TT):
• TC=TT.