1. An electric arc welder for performing a weld process with selected current: waveform performed between an electrode and a workpiece, said welder comprising:
a sensor for acquiring measured values of a welding parameter; and
an error amplifier that derives a wire feed speed control signal for adjusting wire feed speed from the measured values of the welding parameter and a setpoint value.
2. An electric arc welder as set forth in claim 1 wherein the measured values of the welding parameter include measured welding voltage values.
3. An electric arc welder as set forth in claim 2 further comprising:
a digital signal processing block computing a voltage integration value of the measured welding voltage values integrated over a time interval, the error amplifier deriving the wire feed speed control signal using the voltage integration value.
4. An electric arc welder as set forth in claim 3 wherein the error amplifier comprises:
a difference operator computing a difference between the voltage integration value and the setpoint value, the wire feed speed control signal being derived from the computed difference.
5. An electric arc welder as set forth in claim 4 wherein the voltage integration value is selected from a group consisting of (i) an average voltage value over the time interval, (ii) an rms voltage value over the time interval, and (iii) a weighted sum of average voltage value over the time interval and an rms voltage value over the time interval.
6. An electric arc welder as set forth in claim 1 further comprising:
a digital signal processing block computing an integration value of the measured values of the welding parameter integrated over a time interval, the error amplifier deriving the wire feed speed control signal using the integration value.
7. An electric arc welder as set forth in claim 6 wherein the error amplifier comprises:
a difference operator computing a difference between the integration value and the setpoint value, the wire feed speed control signal being derived from the computed difference.
8. An electric arc welder as set forth in claim 7 wherein the integration value comprises an average value of the measured values of the welding parameter over the time interval.
9. An electric arc welder as set forth in claim 7 wherein the integration value comprises an rms value of the measured values of the welding parameter over the time interval.
10. An electric arc welder as set forth in claim 7 wherein the integration value comprises a combination of (i) an rms value of the measured values of the welding parameter over the time interval and (ii) an average value of the measured values of the welding parameter over the time interval.
11. A method for controlling wire feed speed in an electric arc welder, the method comprising:
acquiring a welding value;
computing a wire feed speed control signal based on comparison of the acquired welding value and a setpoint value; and
controlling wire feed speed using the computed wire feed speed control signal.
12. The method as set forth in claim 11, wherein the acquiring of a welding value comprises:
acquiring a welding voltage value.
13. The method as set forth in claim 11, wherein the acquiring includes acquiring instantaneous welding values over a time interval, and the computing comprises:
determining an integration value of the acquired instantaneous welding values integrated over the time interval; and
computing the wire feed speed control signal based on a difference between the integration value and the setpoint value.
14. The method as set forth in claim 13, wherein the acquiring of instantaneous welding values over a time interval comprises:
acquiring instantaneous welding voltage values over the time interval.
15. The method as set forth in claim 14 wherein the integration value is selected from a group consisting of: (i) an average welding voltage value, (ii) an rms welding voltage value, and (iii) a weighted sum of an average welding voltage value and an rms welding voltage value.
16. An electric arc welder comprising:
a controller for adjusting wire feed speed based on a comparison of an acquired welding parameter value and a set point value.
17. The electric arc welder as set forth in claim 16, further comprising:
a digitizing sensor for acquiring instantaneous digital values of a welding parameter, the digital controller computing the acquired welding parameter value from the instantaneous digital values of the welding parameter.
18. The electric arc welder as set forth in claim 17, wherein the controller integrates the acquired instantaneous digital values over a selected time interval to compute the acquired welding parameter value.
19. An electric arc welder as set forth in claim 17, wherein the controller computes the acquired welding parameter value as one of (i) an average value of the acquired instantaneous digital values over a selected time interval, (ii) an rms value of the acquired instantaneous digital values over a selected time interval, and (iii) a combination of an average value and an rms value of the acquired instantaneous digital values over a selected time interval.
20. An electric arc welder as set forth in claim 16 wherein the acquired welding parameter value is computed from an acquired weld voltage value.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of determining an early arrival path of a wireless signal at a device comprising:
capturing a channel energy response at the device;
identifying a first peak in the channel energy response, the first identified peak comprising a maximum value of a first portion of the channel energy response;
positioning and scaling a mask with the first identified peak;
comparing at least a portion of the channel energy response with the mask as positioned and scaled with the first identified peak; and
determining an earliest arrival path based, at least in part, on the comparison of the at least the portion the at least the portion of the channel energy response with the mask as positioned and scaled with the first identified peak.
2. The method of claim 1, further comprising:
(i) identifying, based on the comparison of the at least the portion of the channel energy response with the mask, a next peak, the next identified peak comprising a maximum value of a next portion of the channel energy response, wherein the next identified peak occurs at an earlier time than an earlier identified peak and rises above the mask as positioned and scaled with the earlier identified peak;
(ii) positioning and scaling the mask with the next identified peak; and
(iii) comparing at least a portion of the channel energy response with the mask as positioned and scaled with the next identified peak;
wherein determining the earliest arrival path is further based on the comparison of the at least the portion of the channel energy response with the mask as positioned and scaled with the next identified peak.
3. The method of claim 2, wherein the earlier identified peak is the first identified peak.
4. The method of claim 2, further comprising repeating (i), (ii), and (iii) until no additional peaks rise above the mask as positioned and scaled with a most recently-identified peak.
5. The method of claim 1, further comprising:
identifying a noise threshold; and
comparing at least a portion of the channel energy response with the noise threshold;
wherein determining the earliest arrival path is further based on the comparison of the at least the portion of the channel energy response with the noise threshold.
6. The method of claim 5, further comprising:
determining an expected aliased term; and
adjusting at least a portion of the noise threshold based on the determined expected alias term.
7. The method of claim 1, further comprising selecting the mask from a plurality of masks based on one or more characteristics of the channel energy response.
8. The method of claim 7, wherein the one or more characteristics of the channel energy response includes a power level of a portion of the channel energy response.
9. The method of claim 1, wherein the mask is derived from an auto-correlation function of at least one signal.
10. A mobile device comprising:
a memory;
a wireless communication interface configured to capture a channel energy response; and
a processing unit communicatively coupled to the memory and the wireless communication interface and configured to:
identify a first peak in the channel energy response, the first identified peak comprising a maximum value of a first portion of the channel energy response;
position and scale a mask with the first identified peak;
compare at least a portion of the channel energy response with the mask as positioned and scaled with the first identified peak; and
determine an earliest arrival path based, at least in part, on the comparison of the at least the portion of the channel energy response with the mask as positioned and scaled with the first identified peak.
11. The mobile device of claim 10, wherein the processing unit is further configured to:
(i) identify, based on the comparison of the at least the portion of the channel energy response with the mask, a next peak, wherein the next identified peak comprises a maximum value of a next portion of the channel energy response and occurs at an earlier time than an earlier identified peak and rises above the mask as positioned and scaled with the earlier identified peak;
(ii) position and scale the mask with the next identified peak; and
(iii) compare at least a portion of the channel energy response with the mask as positioned and scaled with the next identified peak;
wherein determining the earliest arrival path is further based on the comparison of the at least the portion of the channel energy response with the mask as positioned and scaled with the next identified peak.
12. The mobile device of claim 11, wherein the processing unit is further configured to repeat (i), (ii), and (iii) until no additional peaks rise above the mask as positioned and scaled with a most recently-identified peak.
13. The mobile device of claim 10, wherein the processing unit is further configured to:
identify a noise threshold; and
compare at least a portion of the channel energy response with the noise threshold;
wherein determining the earliest arrival path is further based on the comparison of the at least the portion of the channel energy response with the noise threshold.
14. The mobile device of claim 13, wherein the processing unit is further configured to:
determine an expected aliased term; and
adjust at least a portion of the noise threshold based on the determined expected alias term.
15. The mobile device of claim 10, wherein the processing unit is further configured to select the mask from a plurality of masks based on one or more characteristics of the channel energy response.
16. The mobile device of claim 15, wherein the one or more characteristics of the channel energy response includes a power level of a portion of the channel energy response.
17. An apparatus comprising:
means for capturing a channel energy response;
means for identifying a first peak in the channel energy response, the first identified peak comprising a maximum value of a first portion of the channel energy response;
means for positioning and scaling a mask with the first identified peak;
means for comparing at least a portion of the channel energy response with the mask as positioned and scaled with the first identified peak; and
means for determining an earliest arrival path based, at least in part, on the comparison of the at least the portion of the channel energy response with the mask as positioned and scaled with the first identified peak.
18. The apparatus of claim 17, further comprising means for:
(i) identifying, based on the comparison of the at least the portion of the channel energy response with the mask, a next peak, the next identified peak comprising a maximum value of a next portion of the channel energy response, wherein the next identified peak occurs at an earlier time than an earlier identified peak and rises above the mask as positioned and scaled with the earlier identified peak;
(ii) positioning and scaling the mask with the next identified peak; and
(iii) comparing at least a portion of the channel energy response with the mask as positioned and scaled with the next identified peak;
wherein determining the earliest arrival path is further based on the comparison of the at least the portion of the channel energy response with the mask as positioned and scaled with the next identified peak.
19. The apparatus of claim 18, wherein the means for performing (i), (ii), and (iii) are configured to repeat (i), (ii), and (iii) until no additional peaks rise above the mask as positioned and scaled with a most recently-identified peak
20. The apparatus of claim 17, further comprising:
means for identifying a noise threshold; and
means for comparing at least a portion of the channel energy response with the noise threshold;
wherein determining the earliest arrival path is further based on the comparison of the at least the portion of the channel energy response with the noise threshold.