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Define a M(H) material, which gives us a nice, properly square, ferrite shape

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This is really a proxy for B(H) curves, but easier to define a square
shape due to the flat slopes.
This commit is contained in:
Colin
2021-09-05 14:33:14 -07:00
parent 2f4470c2fe
commit dd46da1931
2 changed files with 130 additions and 8 deletions
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18
examples/sr_latch.rs
View File

@@ -23,7 +23,7 @@ fn main() {
let m_to_um = |m: f32| (m * 1e6).round() as u32;
let half_depth = depth * 0.5;
let base = "sr-latch-8-sr-longer-time-scale";
let base = "sr-latch-9-higher-Hc";
let boundary_xy = 500e-6;
let boundary_z = 300e-6;
@@ -50,8 +50,16 @@ fn main() {
let mut driver: Driver<_> = Driver::new_spirv(Meters::new(width, height, depth), feat_size);
driver.set_steps_per_stim(1000);
//driver.fill_region(&ferro1_region, mat::db::linear_iron());
driver.fill_region(&ferro1_region, mat::MBFerromagnet::new(-0.3899, 0.3900, 310_000.0));
driver.fill_region(&ferro2_region, mat::MBFerromagnet::new(-0.3899, 0.3900, 310_000.0));
// Original, 3R1-LIKE ferromagnet (only a vague likeness), sr-latch-8:
// driver.fill_region(&ferro1_region, mat::MBFerromagnet::new(-0.3899, 0.3900, 310_000.0));
// driver.fill_region(&ferro2_region, mat::MBFerromagnet::new(-0.3899, 0.3900, 310_000.0));
// sr-latch-9; dead spot from B=[-0.03, 0.03]. This will help us see if the math is H-triggered
// or B-triggered
driver.fill_region(&ferro1_region, mat::MBFerromagnet::new(-0.3300, 0.3900, 310_000.0));
driver.fill_region(&ferro2_region, mat::MBFerromagnet::new(-0.3300, 0.3900, 310_000.0));
// mu_r=881.33, starting at H=25 to H=75.
// driver.fill_region(&ferro1_region, mat::MBFerromagnet::new(3.14159e-5, 0.055376, 44066.71));
// driver.fill_region(&ferro2_region, mat::MBFerromagnet::new(3.14159e-5, 0.055376, 44066.71));
driver.fill_region(&set_region, mat::db::conductor(drive_conductivity));
driver.fill_region(&reset_region, mat::db::conductor(drive_conductivity));
driver.fill_region(&coupling_region, mat::db::conductor(drive_conductivity));
@@ -102,7 +110,7 @@ fn main() {
add_drive_pulse(&reset_region, 55.0*current_duration, current_duration, peak_stim1);
add_drive_pulse(&set_region, 55.0*current_duration, current_duration, peak_stim1);
let duration = 240.0*current_duration;
let duration = 120.0*current_duration;
driver.add_measurement(meas::CurrentLoop::new("coupling", coupling_region.clone()));
driver.add_measurement(meas::Current::new("coupling", coupling_region.clone()));
@@ -132,7 +140,7 @@ fn main() {
let _ = std::fs::create_dir_all(&prefix);
driver.add_state_file(&*format!("{}/state.bc", prefix), 9600);
driver.add_serializer_renderer(&*format!("{}/frame-", prefix), 36000);
// driver.add_serializer_renderer(&*format!("{}/frame-", prefix), 36000);
driver.add_csv_renderer(&*format!("{}/meas.csv", prefix), 200);
driver.add_csv_renderer(&*format!("{}/meas-sparse.csv", prefix), 1600);

120
src/sim/spirv_backend/src/mat.rs
View File

@@ -55,6 +55,66 @@ impl MBPgram {
}
}
#[derive(Copy, Clone, Default)]
pub struct MHPgram {
/// X coordinate at which M is always zero.
h_intercept: f32,
/// relative mu value along the non-flat edges of the parallelogram.
mu_r: f32,
/// Vertical range of the graph
max_m: f32,
}
impl MHPgram {
pub fn new(h_intercept: f32, mu_r: f32, max_m: f32) -> Self {
Self { h_intercept, mu_r, max_m }
}
/// Return the new `M`
pub fn move_b(self, m: f32, target_b: f32) -> f32 {
const MU0_INV: f32 = 795774.715025073;
let target_mh = target_b*MU0_INV;
// The point may exist outside the parallelogram.
// The right slope is defined by:
// B(H)/mu0 = h_intercept + (h-h_intercept)*mu_r
// Left:
// B(H)/mu0 = -h_intercept + (h+h_intercept)*mu_r
let h_on_right = (target_mh-self.h_intercept)/self.mu_r + self.h_intercept;
let m_on_right = target_mh - h_on_right;
let h_on_left = (target_mh+self.h_intercept)/self.mu_r - self.h_intercept;
let m_on_left = target_mh - h_on_left;
if m_on_right >= m {
if m_on_right <= self.max_m {
// rightward edge movement
m_on_right
} else {
// right of saturation
self.max_m
}
} else if m_on_left <= m {
if m_on_left >= -self.max_m {
// leftward edge movement
m_on_left
} else {
// left of saturation
-self.max_m
}
} else {
// interior movement
m
}
}
pub fn move_b_vec(self, m: Vec3Std, target_b: Vec3Std) -> Vec3Std {
Vec3Std::new(
self.move_b(m.x(), target_b.x()),
self.move_b(m.y(), target_b.y()),
self.move_b(m.z(), target_b.z()),
)
}
}
#[cfg(test)]
mod test {
use super::*;
@@ -68,7 +128,7 @@ mod test {
}
#[test]
fn curve_interior() {
fn mb_curve_interior() {
let curve = MBPgram::new(4.0, 6.0, 20.0f32);
assert_eq_approx_tight(curve.move_b(0.0, 2.0), 0.0);
@@ -82,7 +142,7 @@ mod test {
}
#[test]
fn curve_exterior() {
fn mb_curve_exterior() {
let curve = MBPgram::new(4.0, 6.0, 20.0f32);
assert_eq_approx_tight(curve.move_b(0.0, 6.0), 20.0);
assert_eq_approx_tight(curve.move_b(0.0, 7.0), 20.0);
@@ -100,7 +160,7 @@ mod test {
}
#[test]
fn curve_3r1() {
fn mb_curve_3r1() {
// slope of 3r1 is about M=793210*B
// This is almost identical to iron (795615)!
let curve = MBPgram::new(-0.3899, 0.3900, 310000f32);
@@ -130,4 +190,58 @@ mod test {
// the magnetization has been completely erased:
assert_eq_approx(curve.move_b(310000.0, -0.25), -198703.0, 1.0);
}
#[test]
fn mh_curve_edge_travel() {
const MU0: f32 = 1.2566370621219e-06;
let curve = MHPgram::new(50.0, 101.0, 500.0);
assert_eq_approx(curve.move_b(0.0, 151.0*MU0), 100.0, 0.1); // rightward travel along edge
assert_eq_approx(curve.move_b(100.0, 252.0*MU0), 200.0, 0.1);
assert_eq_approx(curve.move_b(200.0, 555.0*MU0), 500.0, 0.1);
assert_eq_approx(curve.move_b(500.0, 500.0*MU0), 500.0, 0.1); // back (leftward) travel to H=0
assert_eq_approx(curve.move_b(500.0, 455.0*MU0), 500.0, 0.1); // back (leftward) travel to H=-45
assert_eq_approx(curve.move_b(500.0, 354.0*MU0), 400.0, 0.1); // back (leftward) travel to H=-46
assert_eq_approx(curve.move_b(400.0, 253.0*MU0), 300.0, 0.1); // back (leftward) travel to H=-47
assert_eq_approx(curve.move_b(300.0, -50.0*MU0), 0.0, 0.1); // back (leftward) travel to H=-50
assert_eq_approx(curve.move_b(0.0, -151.0*MU0), -100.0, 0.1); // back (leftward) travel to H=-51
assert_eq_approx(curve.move_b(-100.0, -555.0*MU0), -500.0, 0.1); // back (leftward) travel to H=-55
assert_eq_approx(curve.move_b(-500.0, -456.0*MU0), -500.0, 0.1); // interior (rightward) travel to H=44
assert_eq_approx(curve.move_b(-500.0, -354.0*MU0), -400.0, 0.1); // interior (rightward) travel to H=46
assert_eq_approx(curve.move_b(-400.0, -253.0*MU0), -300.0, 0.1); // interior (rightward) travel to H=47
assert_eq_approx(curve.move_b(-300.0, 50.0*MU0), 0.0, 0.1); // interior (rightward) travel to H=50
}
#[test]
fn mh_curve_interior() {
const MU0: f32 = 1.2566370621219e-06;
let curve = MHPgram::new(50.0, 101.0, 500.0);
// max M (right) happens at H=55; B = 555*MU0;
// min M (right) happens at H=45; B = -455*MU0;
// max M (left) happens at H=-45; B = 455*MU0;
// min M (left) happens at H=-55; B = -555*MU0;
assert_eq_approx(curve.move_b(0.0, 40.0*MU0), 0.0, 0.1);
assert_eq_approx(curve.move_b(0.0, 50.0*MU0), 0.0, 0.1);
assert_eq_approx(curve.move_b(0.0, -40.0*MU0), 0.0, 0.1);
assert_eq_approx(curve.move_b(0.0, -50.0*MU0), 0.0, 0.1);
assert_eq_approx(curve.move_b(-400.0, -400.0*MU0), -400.0, 0.1); // rightward travel from H=-54 to NOT H=-53.5
assert_eq_approx(curve.move_b(-400.0, -355.0*MU0), -400.0, 0.1); // rightward travel from H=-54 to H=45
assert_eq_approx(curve.move_b(-400.0, -354.0*MU0), -400.0, 0.1); // rightward travel from H=-54 to H=46
assert_eq_approx(curve.move_b(-400.0, 5000.0*MU0), 500.0, 0.1); // rightward travel from H=-54 to H>>55
}
#[test]
fn mh_curve_exterior() {
const MU0: f32 = 1.2566370621219e-06;
let curve = MHPgram::new(50.0, 101.0, 500.0);
assert_eq_approx(curve.move_b(500.0, 556.0*MU0), 500.0, 0.1); // exterior travel to H=56
assert_eq_approx(curve.move_b(500.0, 5000.0*MU0), 500.0, 0.1); // exterior travel to H>>55
assert_eq_approx(curve.move_b(500.0, -5000.0*MU0), -500.0, 0.1); // exterior travel from H>>55 to H << -55
assert_eq_approx(curve.move_b(-501.0, 454.0*MU0), 400.0, 0.1); // exterior travel from H<<-55 (rounding error) to H=54
}
}