[Diff since v1.10.4](v1.10.4...v1.10.5)

**Merged pull requests:**
- use eps of correct type in balreal (#927) (@baggepinnen)
- Update `minreal` docstring (#935) (@franckgaga)
- add fix for step with plotx and MIMO systems (#936) (@baggepinnen)
- add functions returning the resolvent of a system (#939) (@baggepinnen)
- bump compat DiffEqCallbacks (#940) (@baggepinnen)

**Closed issues:**
- Revisiting old code: was there ever an `LTISystem` composed type in `ControlSystems.jl`? (#938)

[Diff since v1.10.3](v1.10.3...v1.10.4)

**Merged pull requests:**
- Add "asymptotic" keyword to `kalman` docstring (#929) (@franckgaga)
- add `\` for ss and handle some cases of multiplication with improper tf (#930) (@baggepinnen)
- Update zoh.md (#933) (@baggepinnen)
- handle non-identity uniform scalings in covar (#934) (@baggepinnen)

**Closed issues:**
- Optimization-based tuning–PID controller with Delay (#931)
- An incorrect formula in the documentation (#932)

[Diff since v1.10.2](v1.10.2...v1.10.3)

**Merged pull requests:**
- more helpful error message in baltrunc (#926) (@baggepinnen)
- bump compat DiffEqCallbacks (#928) (@baggepinnen)

**Closed issues:**
- B matrix cannot contain too many zero elements for baltrunc (#925)

[Diff since v1.10.1](v1.10.1...v1.10.2)

**Merged pull requests:**
- Fix Bode plot with zero magnitude (#911) (@baggepinnen)
- try enable CI caches (#914) (@baggepinnen)
- handle rounding error in Nyquist freq for default freq vec (#915) (@baggepinnen)
- Update compat OrdinaryDiffEq (#923) (@baggepinnen)

**Closed issues:**
- Discrete bode default axis ranges (#438)
- Change input/output plot order of SimResult (#919)
- Step response (at a t0 instant) of a first order system with delay doesn't work correctly with lsim (but works fine with step but with t0=0) (#920)

[Diff since v1.10.0](v1.10.0...v1.10.1)

**Merged pull requests:**
- try make codecov look at results from all test groups (#907) (@baggepinnen)
- fix #909 (#910) (@baggepinnen)

**Closed issues:**
- d2c_exact should work with gains (i.e. state space systems without states) (#909)

[Diff since v1.9.0](v1.9.0...v1.10.0)

**Merged pull requests:**
- add Thiran approximation of fractional-delay systems (#905) (@baggepinnen)
- handle proper quotient of proper statespace systems (#906) (@baggepinnen)

[Diff since v1.8.2](v1.8.2...v1.9.0)

**Merged pull requests:**
- more coverage (#893) (@baggepinnen)
- bump compat poly v4 (#899) (@baggepinnen)
- Convert pid parameters to :parallel (#900) (@mzaffalon)
- Add exact frequency-domain translation of discrete systems to continuous time (#902) (@baggepinnen)
- add tutorial analyzing hybrid systems (#903) (@baggepinnen)

**Closed issues:**
- Gamma contour in Nyquist plot (#796)
- `pid` with zero proportional gain (#897)
- ControlSystemsBase blocking Polynomials.jl v4 (#898)

[Diff since v1.8.1](v1.8.1...v1.8.2)

**Merged pull requests:**
- try activating coverage for subpackage (#763) (@baggepinnen)
- add section on dealing with model uncertainty in tutorial (#884) (@baggepinnen)
- Upper-bound length of default time vector (#887) (@baggepinnen)
- depend on StaticArraysCore instead of StaticArrays (#888) (@baggepinnen)
- add more emphasis on model uncertainty in tutorial (#889) (@baggepinnen)
- Fix `append` for delay system (#892) (@baggepinnen)
- remove duplicated file (#894) (@baggepinnen)
- better error message in lsim (#895) (@baggepinnen)
- add method to `DSP.filt` and `filtfilt` (#896) (@baggepinnen)

**Closed issues:**
- bodeplot does not work well with plotlyjs backend (#875)
- `append` on `DelayLtiSystem` does not works (#879)
- OutOfMemoryError on step without time step size (#880)
- named transfer functions (#885)
- minreal returns system of order 21 instead of order 5. (#890)
- add tolerance to `tzeros` (#891)

[Diff since v1.8.0](v1.8.0...v1.8.1)

**Merged pull requests:**
- remove automatic field propagation from `balance_statespace` (#863) (@baggepinnen)
- truncate T in baltrunc (#864) (@baggepinnen)
- add functions to check controllability/observability using the PHB test (#866) (@baggepinnen)
- fix rendering of some equations systems (#868) (@baggepinnen)
- use correct gain type in zpk with length 0 numerator (#870) (@baggepinnen)
- fix transfer function colon indexing (#872) (@baggepinnen)
- fix unwrapping option in bodeplot (#874) (@baggepinnen)
- safe dtmax in continuous lsim (#876) (@baggepinnen)
- fix DelaySS conversion with special number type (#878) (@baggepinnen)
- Incorporate changes from #344 (#881) (@KronosTheLate)
- add tutorial on controller tuning from experimental data (#883) (@baggepinnen)

**Closed issues:**
- SisoZpk and SisoRational constructors called multiple times from zpk and tf (#387)
- Rendering of state space equations in documentation (#867)
- no method matching zpk for step (#869)
- Using `:` for indexing does not works on `TransferFunction` (#871)
- c2d not working with method input (#873)
- change to ControlSystems dosent work for import pkg (#877)

[Diff since v1.7.4](v1.7.4...v1.8.0)

**Closed issues:**
- `ssdata` & storage format of systems? (#857)

**Merged pull requests:**
- make schur factorization differentiable (#849) (@baggepinnen)
- fix typos (#858) (@spaette)
- add linearization utility (#859) (@baggepinnen)
- Always draw up to Nyquist frequency for discrete systems (#860) (@baggepinnen)
- add option to design observers with direct term (#861) (@baggepinnen)
- add discretization of cost and covariance matrices (#862) (@baggepinnen)