use runmat_builtins::{
BuiltinCompletionPolicy, BuiltinDescriptor, BuiltinErrorDescriptor, BuiltinOutputMode,
BuiltinParamArity, BuiltinParamDescriptor, BuiltinParamType, BuiltinSignatureDescriptor, Value,
};
use runmat_macros::runtime_builtin;
use crate::builtins::common::spec::{
BroadcastSemantics, BuiltinFusionSpec, BuiltinGpuSpec, ConstantStrategy, GpuOpKind,
ReductionNaN, ResidencyPolicy, ShapeRequirements,
};
use crate::builtins::control::tf_model::{scalar_f64, two_models_ordered};
use crate::builtins::control::type_resolvers::feedback_type;
use crate::{BuiltinResult, RuntimeError};
const BUILTIN_NAME: &str = "feedback";
const FEEDBACK_OUTPUT: [BuiltinParamDescriptor; 1] = [BuiltinParamDescriptor {
name: "sys",
ty: BuiltinParamType::Any,
arity: BuiltinParamArity::Required,
default: None,
description: "Closed-loop SISO transfer-function object.",
}];
const FEEDBACK_PARAM_SYS1: BuiltinParamDescriptor = BuiltinParamDescriptor {
name: "sys1",
ty: BuiltinParamType::Any,
arity: BuiltinParamArity::Required,
default: None,
description: "Forward-path SISO transfer-function model.",
};
const FEEDBACK_PARAM_SYS2: BuiltinParamDescriptor = BuiltinParamDescriptor {
name: "sys2",
ty: BuiltinParamType::Any,
arity: BuiltinParamArity::Optional,
default: Some("1"),
description: "Feedback-path SISO transfer function or scalar gain.",
};
const FEEDBACK_PARAM_SIGN: BuiltinParamDescriptor = BuiltinParamDescriptor {
name: "sign",
ty: BuiltinParamType::NumericScalar,
arity: BuiltinParamArity::Optional,
default: Some("-1"),
description: "-1 for negative feedback or +1 for positive feedback.",
};
const FEEDBACK_INPUT_SYS: [BuiltinParamDescriptor; 1] = [FEEDBACK_PARAM_SYS1];
const FEEDBACK_INPUT_SYS_OTHER: [BuiltinParamDescriptor; 2] =
[FEEDBACK_PARAM_SYS1, FEEDBACK_PARAM_SYS2];
const FEEDBACK_INPUT_SYS_OTHER_SIGN: [BuiltinParamDescriptor; 3] = [
FEEDBACK_PARAM_SYS1,
FEEDBACK_PARAM_SYS2,
FEEDBACK_PARAM_SIGN,
];
const FEEDBACK_SIGNATURES: [BuiltinSignatureDescriptor; 3] = [
BuiltinSignatureDescriptor {
label: "sys = feedback(sys1)",
inputs: &FEEDBACK_INPUT_SYS,
outputs: &FEEDBACK_OUTPUT,
},
BuiltinSignatureDescriptor {
label: "sys = feedback(sys1, sys2)",
inputs: &FEEDBACK_INPUT_SYS_OTHER,
outputs: &FEEDBACK_OUTPUT,
},
BuiltinSignatureDescriptor {
label: "sys = feedback(sys1, sys2, sign)",
inputs: &FEEDBACK_INPUT_SYS_OTHER_SIGN,
outputs: &FEEDBACK_OUTPUT,
},
];
const FEEDBACK_ERRORS: [BuiltinErrorDescriptor; 5] = [
BuiltinErrorDescriptor {
code: "RM.FEEDBACK.INVALID_ARGUMENT",
identifier: Some("RunMat:feedback:InvalidArgument"),
when: "Inputs do not match supported feedback invocation forms.",
message: "feedback: invalid argument",
},
BuiltinErrorDescriptor {
code: "RM.FEEDBACK.INVALID_MODEL",
identifier: Some("RunMat:feedback:InvalidModel"),
when: "Input systems are not supported SISO transfer-function models.",
message: "feedback: invalid model",
},
BuiltinErrorDescriptor {
code: "RM.FEEDBACK.INVALID_SIGN",
identifier: Some("RunMat:feedback:InvalidSign"),
when: "Feedback sign is not -1 or +1.",
message: "feedback: sign must be -1 or +1",
},
BuiltinErrorDescriptor {
code: "RM.FEEDBACK.UNSUPPORTED_MODEL",
identifier: Some("RunMat:feedback:UnsupportedModel"),
when: "A supported-looking model uses unsupported delays or incompatible sample times.",
message: "feedback: unsupported model",
},
BuiltinErrorDescriptor {
code: "RM.FEEDBACK.INTERNAL",
identifier: Some("RunMat:feedback:Internal"),
when: "Closed-loop transfer-function assembly failed.",
message: "feedback: internal error",
},
];
pub const FEEDBACK_DESCRIPTOR: BuiltinDescriptor = BuiltinDescriptor {
signatures: &FEEDBACK_SIGNATURES,
output_mode: BuiltinOutputMode::Fixed,
completion_policy: BuiltinCompletionPolicy::Public,
errors: &FEEDBACK_ERRORS,
};
#[runmat_macros::register_gpu_spec(builtin_path = "crate::builtins::control::feedback")]
pub const GPU_SPEC: BuiltinGpuSpec = BuiltinGpuSpec {
name: "feedback",
op_kind: GpuOpKind::Custom("control-feedback-interconnection"),
supported_precisions: &[],
broadcast: BroadcastSemantics::None,
provider_hooks: &[],
constant_strategy: ConstantStrategy::InlineLiteral,
residency: ResidencyPolicy::GatherImmediately,
nan_mode: ReductionNaN::Include,
two_pass_threshold: None,
workgroup_size: None,
accepts_nan_mode: false,
notes: "SISO transfer-function interconnection runs on host-side metadata.",
};
#[runmat_macros::register_fusion_spec(builtin_path = "crate::builtins::control::feedback")]
pub const FUSION_SPEC: BuiltinFusionSpec = BuiltinFusionSpec {
name: "feedback",
shape: ShapeRequirements::Any,
constant_strategy: ConstantStrategy::InlineLiteral,
elementwise: None,
reduction: None,
emits_nan: false,
notes: "feedback creates a transfer-function object and terminates numeric fusion chains.",
};
fn feedback_error(
message: impl Into<String>,
error: &'static BuiltinErrorDescriptor,
) -> RuntimeError {
let mut builder = crate::build_runtime_error(message).with_builtin(BUILTIN_NAME);
if let Some(identifier) = error.identifier {
builder = builder.with_identifier(identifier);
}
builder.build()
}
#[runtime_builtin(
name = "feedback",
category = "control",
summary = "Form SISO feedback interconnections for transfer-function models.",
keywords = "feedback,control system,closed loop,transfer function,tf",
type_resolver(feedback_type),
descriptor(crate::builtins::control::feedback::FEEDBACK_DESCRIPTOR),
builtin_path = "crate::builtins::control::feedback"
)]
async fn feedback_builtin(sys1: Value, rest: Vec<Value>) -> BuiltinResult<Value> {
if rest.len() > 2 {
return Err(feedback_error(
"feedback: expected feedback(sys1), feedback(sys1, sys2), or feedback(sys1, sys2, sign)",
&FEEDBACK_ERRORS[0],
));
}
let sys2 = rest.first().cloned().unwrap_or(Value::Num(1.0));
let sign = match rest.get(1) {
Some(value) => {
let gathered = crate::dispatcher::gather_if_needed_async(value).await?;
scalar_f64(&gathered, "sign", BUILTIN_NAME)?
}
None => -1.0,
};
if sign != -1.0 && sign != 1.0 {
return Err(feedback_error(
"feedback: sign must be -1 or +1",
&FEEDBACK_ERRORS[2],
));
}
let (forward, feedback_path) = two_models_ordered(sys1, sys2, BUILTIN_NAME).await?;
forward
.feedback(&feedback_path, sign)?
.to_value(BUILTIN_NAME)
}
#[cfg(test)]
mod tests {
use super::*;
use futures::executor::block_on;
use runmat_builtins::Tensor;
fn tf(num: Vec<f64>, den: Vec<f64>) -> Value {
block_on(crate::call_builtin_async(
"tf",
&[
Value::Tensor(Tensor::new(num.clone(), vec![1, num.len()]).unwrap()),
Value::Tensor(Tensor::new(den.clone(), vec![1, den.len()]).unwrap()),
],
))
.expect("tf")
}
fn coeff(value: &Value, field: &str) -> Vec<f64> {
let Value::Object(object) = value else {
panic!("expected tf object");
};
let Value::Tensor(tensor) = object.properties.get(field).expect(field) else {
panic!("expected tensor");
};
tensor.data.clone()
}
#[test]
fn unity_negative_feedback_forms_closed_loop() {
let g = tf(vec![2.0], vec![1.0, 3.0]);
let out = block_on(feedback_builtin(g, vec![Value::Num(1.0)])).expect("feedback");
assert_eq!(coeff(&out, "Numerator"), vec![2.0]);
assert_eq!(coeff(&out, "Denominator"), vec![1.0, 5.0]);
}
#[test]
fn positive_feedback_subtracts_loop_gain() {
let g = tf(vec![2.0], vec![1.0, 3.0]);
let out = block_on(feedback_builtin(g, vec![Value::Num(1.0), Value::Num(1.0)]))
.expect("feedback");
assert_eq!(coeff(&out, "Numerator"), vec![2.0]);
assert_eq!(coeff(&out, "Denominator"), vec![1.0, 1.0]);
}
}