Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Post History

60%
+1 −0
Q&A Moving average that uses less memory?

A bit of a tangent, but in mcu firmwares, higher order filters can also be implemented directly with biquad sections. More work to implement vs single pole, but very reusable. Although to be honest...

posted 3y ago by Pete W‭  ·  edited 3y ago by Pete W‭

Answer
#3: Post edited by user avatar Pete W‭ · 2020-12-16T05:09:54Z (over 3 years ago)
  • A bit of a tangent, but higher order filters can also be implemented with biquad sections. More work to implement vs single pole, but very reusable. Although to be honest the benefit over cascaded single-poles is marginal, so there may be other topics, like loop stability, that might be a better use of someone's time, if they are at the stage when asking the question originally posted.
  • The main difference betw. biquads and single-pole's is the ability to place complex poles and zeros. IMO this is not actually desirable for filtering process data from typical sensors, due to underdamped step response.
  • On the other hand ability to place complex poles and zeros CAN open up more options when put to use inside a control loop, for more difficult situations. You have to kindof enjoy the math to take this route.
  • A bit of a tangent, but in mcu firmwares, higher order filters can also be implemented directly with biquad sections. More work to implement vs single pole, but very reusable. Although to be honest the benefit over cascaded single-poles is marginal, so there may be other topics, like loop stability, that might be a better use of someone's time, if they are at the stage when asking the question originally posted.
  • The main difference betw. biquads and single-pole's is the ability to place complex poles and zeros. IMO this is not actually desirable for filtering process data from typical sensors, due to underdamped step response.
  • On the other hand ability to place complex poles and zeros CAN open up more options when put to use inside a control loop, for more difficult situations. You have to kindof enjoy the math to take this route.
#2: Post edited by user avatar Pete W‭ · 2020-12-16T04:51:00Z (over 3 years ago)
  • A bit of a tangent, but higher order filters can also be implemented with biquad sections. More work to implement vs single pole, but very reusable. Although to be honest the benefit over cascaded single-poles is marginal, so there may be other topics, like loop stability, that might be a better use of the OP's time.
  • The main thing biquads let you do is create complex poles and zeros, if you want. IMO this is not actually desirable for filtering process data, due to underdamped step response. On the other hand ability to place complex poles and zeros CAN open up more options when put to use inside a control loop.
  • You have to kindof enjoy the math to take this route.
  • A bit of a tangent, but higher order filters can also be implemented with biquad sections. More work to implement vs single pole, but very reusable. Although to be honest the benefit over cascaded single-poles is marginal, so there may be other topics, like loop stability, that might be a better use of someone's time, if they are at the stage when asking the question originally posted.
  • The main difference betw. biquads and single-pole's is the ability to place complex poles and zeros. IMO this is not actually desirable for filtering process data from typical sensors, due to underdamped step response.
  • On the other hand ability to place complex poles and zeros CAN open up more options when put to use inside a control loop, for more difficult situations. You have to kindof enjoy the math to take this route.
#1: Initial revision by user avatar Pete W‭ · 2020-12-16T04:48:28Z (over 3 years ago)
A bit of a tangent, but higher order filters can also be implemented with biquad sections. More work to implement vs single pole, but very reusable. Although to be honest the benefit over cascaded single-poles is marginal, so there may be other topics, like loop stability, that might be a better use of the OP's time.

The main thing biquads let you do is create complex poles and zeros, if you want. IMO this is not actually desirable for filtering process data, due to underdamped step response. On the other hand ability to place complex poles and zeros CAN open up more options when put to use inside a control loop.

You have to kindof enjoy the math to take this route.