38 lines
1.2 KiB
Markdown
38 lines
1.2 KiB
Markdown
# How the inverse kinematics is calculated
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The concept uses the following assumptions:
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* The degrees-of-freedom are limited to
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* Shoulder joint with 3dof and restrictive joint limits
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* The elbow with only 1dof
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* The wrist with 3dof and restrictive joint limits
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* for humans, within the reachable elbow positions, some areas are more likely to be used due to less muscle strain
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## Proposal 1 for am pose estimate
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Input:
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* controller position
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* shoulder position estimate
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Output:
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* Elbow position
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* Shoulder backslash (required to improve shoulder position estimate)
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### Step 1: Initial elbow position estimate
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We try to get a first good estimate using a very simple method: given
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* a vector *SpineShoulder*, going from the spine at approx. breast-hight to the shoulder position, and
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* a vector *ShoulderWrist*, going from the shoulder to the wrist position, which can be easily inferred from the controller position,
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* calculate the cross-product like this for the **right shoulder**:
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```var elbow_dir = SpineShoulder.cross(ShoulderWrist)```.
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### Step 2: Consider controller orientation
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### Step 3: Consider shoulder orientation
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### Step 4: Determine shoulder backslash for shoulder position estimation
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