From 44cfa7b563daa8415206a8a24025edfd2df7e3d7 Mon Sep 17 00:00:00 2001 From: cao-xiao-hao <127832643+cao-xiao-hao@users.noreply.github.com> Date: Tue, 13 Oct 2026 16:52:01 +0800 Subject: [PATCH] fix: replace the factory calibration with the re-measured geometry The shipped default calibration is what a no-argument load_calibration() reads, so it drives the travel clamp and every mm-based target. It carried zero_position_rad 0.052071, max_position_rad -1.357481 and rad_to_mm 61.01229326764816; the shipped unit reads 0.029564, -1.141184 and 73.45731105242119. Both files span the same 86 mm (travel_range_rad * rad_to_mm == 86.0), so neither is self-inconsistent and reading one file alone cannot say which is wrong. Only the absolute values separate them, which is why the shipped geometry is pinned by test rather than checked for internal consistency. rad_to_mm rises by a factor of 1.204, so every mm-based target and the clamp_to_calibrated limits move with it: open() at work_stroke_mm 80.0 lands at a different angle than before. That is what a recalibration is for, not a side effect to be worked around, but it does change the behaviour of anything pinned to the old default. The two direction templates move to the same geometry, so the three shipped files keep describing one unit. The test that used the factory file as its example of a pre-`calibrated`-flag file now writes its own, because the shipped file carries the flag and the fallback it covers is about a missing key, not about that file. --- src/litegrip/calibration_normal.json | 8 ++-- src/litegrip/calibration_reverse.json | 8 ++-- src/litegrip/constants.py | 6 +-- src/litegrip/factory_calibration.json | 13 ++++--- tests/test_calibration.py | 53 ++++++++++++++++++++------- 5 files changed, 57 insertions(+), 31 deletions(-) diff --git a/src/litegrip/calibration_normal.json b/src/litegrip/calibration_normal.json index 0b37d9d..f57aad2 100644 --- a/src/litegrip/calibration_normal.json +++ b/src/litegrip/calibration_normal.json @@ -1,9 +1,9 @@ { "calibrated": true, - "zero_position_rad": 0.052071, - "max_position_rad": -1.357481, - "travel_range_rad": 1.409552, - "rad_to_mm": 61.01229326764816, + "zero_position_rad": 0.029564, + "max_position_rad": -1.141184, + "travel_range_rad": 1.170748, + "rad_to_mm": 73.45731105242119, "work_stroke_mm": 80.0, "motor_type": "DM4310" } diff --git a/src/litegrip/calibration_reverse.json b/src/litegrip/calibration_reverse.json index 94e48da..44584ca 100644 --- a/src/litegrip/calibration_reverse.json +++ b/src/litegrip/calibration_reverse.json @@ -1,9 +1,9 @@ { "calibrated": true, - "zero_position_rad": -1.357481, - "max_position_rad": 0.052071, - "travel_range_rad": 1.409552, - "rad_to_mm": 61.01229326764816, + "zero_position_rad": -1.141184, + "max_position_rad": 0.029564, + "travel_range_rad": 1.170748, + "rad_to_mm": 73.45731105242119, "work_stroke_mm": 80.0, "motor_type": "DM4310" } diff --git a/src/litegrip/constants.py b/src/litegrip/constants.py index 01690f5..a101f41 100644 --- a/src/litegrip/constants.py +++ b/src/litegrip/constants.py @@ -70,9 +70,9 @@ class GripperGeometry: millimetres-per-radian scale is that span over the measured travel in radians (``rad_to_mm``); deriving it from the 85 mm jaw travel instead would leave every mm-based move 1.2% short — 1 mm lost per full stroke. - The factory calibration's own numbers show the pair: 1.409552 rad of - travel is 86 mm at ``61.01229326764816`` mm/rad, and 85 mm at - ``60.303``. + The factory calibration's own numbers show the pair: 1.170748 rad of + travel is 86 mm at ``73.45731105242119`` mm/rad, and 85 mm at + ``72.604``. ``work_stroke_mm`` is measured from the closed zero like :attr:`JAW_TRAVEL_MM`, so a full-stroke ``work_stroke_mm`` is 85 mm, not diff --git a/src/litegrip/factory_calibration.json b/src/litegrip/factory_calibration.json index 465dc8a..a2d0ece 100644 --- a/src/litegrip/factory_calibration.json +++ b/src/litegrip/factory_calibration.json @@ -1,15 +1,16 @@ { "channel": "can0", "can_id": 8, - "mst_id": 24, "canfd_mode": false, - "zero_position_rad": 0.052071, - "max_position_rad": -1.357481, - "travel_range_rad": 1.409552, - "rad_to_mm": 61.01229326764816, + "calibrated": true, + "zero_position_rad": 0.029564, + "max_position_rad": -1.141184, + "travel_range_rad": 1.170748, + "rad_to_mm": 73.45731105242119, "work_stroke_mm": 80.0, "motor_type": "DM4310", "kp": 100.0, "kd": 2.0, - "grasp_torque_threshold": 0.5 + "grasp_torque_threshold": 0.5, + "mst_id": 24 } diff --git a/tests/test_calibration.py b/tests/test_calibration.py index f7fd96c..4f85408 100644 --- a/tests/test_calibration.py +++ b/tests/test_calibration.py @@ -90,15 +90,19 @@ class TestShippedCalibrationFiles(unittest.TestCase): 三份文件各自独立，曾同时停在 ``0.0 / -1.651026 / 52.69``（另一台夹爪的 读数），而出厂值（litegrip-cpp 的 ``calibration/factory_calibration.json``） - 是 ``0.052071 / -1.357481 / 61.01229326764816``。这里把出厂几何钉住，并 + 是 ``0.029564 / -1.141184 / 73.45731105242119``。这里把出厂几何钉住，并 检查三份文件**互相一致**：只改一半（换了 ``rad_to_mm`` 忘了 ``travel_range_rad``）会让 ``open()`` 的行程算错，而单看一份文件看不出来。 + + 出厂几何换过一代：上一代是 ``0.052071 / -1.357481 / 61.01229326764816``， + 同一段 86 mm 跨度记成 ``1.409552`` rad。两代都自洽（跨度都是 86 mm），所以 + 单看一份文件分不出哪份是错的 —— 这正是必须把绝对值钉死、不能只查自洽的原因。 """ # litegrip-cpp/calibration/factory_calibration.json - FACTORY_CLOSED_RAD = 0.052071 # zero_position_rad - FACTORY_OPEN_RAD = -1.357481 # max_position_rad - FACTORY_RAD_TO_MM = 61.01229326764816 + FACTORY_CLOSED_RAD = 0.029564 # zero_position_rad + FACTORY_OPEN_RAD = -1.141184 # max_position_rad + FACTORY_RAD_TO_MM = 73.45731105242119 FACTORY_TRAVEL_MM = 86.0 def _load(self, path): @@ -199,11 +203,23 @@ def test_saved_file_records_calibrated(self): self.assertTrue(json.load(f)["calibrated"]) def test_old_file_without_the_flag_counts_as_calibrated(self): - """工厂文件是 flag 之前的格式，缺键不能当未标定。""" - with open(_FACTORY_CALIB) as f: + """老文件是 flag 之前的格式，缺键不能当未标定。 + + 这个 fixture 自己写 ``calibrated`` 之前的字段，不再借出厂文件当例子 + —— 出厂文件现在带 ``calibrated: true``，一旦它再改格式，这条测试就会 + 因为格式无关的原因红掉（而它在测的是**缺键**的语义，不是出厂文件的内容）。 + """ + path = self._path() + _write_json({"channel": "can0", + "zero_position_rad": 0.052071, + "max_position_rad": -1.357481, + "travel_range_rad": 1.409552, + "rad_to_mm": 61.01229326764816, + "work_stroke_mm": 80.0}, self.dir) + with open(path) as f: self.assertNotIn("calibrated", json.load(f)) g = LiteGrip("can0") - self.assertTrue(g.load_calibration(_FACTORY_CALIB)) + self.assertTrue(g.load_calibration(path)) self.assertTrue(g.config.calibrated) def test_channel_mismatch_warns(self): @@ -273,11 +289,11 @@ class TestDerivedScale(unittest.TestCase): """ def test_the_reference_scale_is_the_hand_recorded_one(self): - """(85 + 1) / 1.409552 必须等于出厂文件里手记的那一个。""" + """(85 + 1) / 1.170748 必须等于出厂文件里手记的那一个。""" self.assertAlmostEqual( (GripperGeometry.JAW_TRAVEL_MM + GripperGeometry.STOP_INSET_MM) - / 1.409552, - 61.01229326764816, + / 1.170748, + 73.45731105242119, places=9) def test_re_running_the_probe_on_a_shipped_unit_reproduces_its_scale(self): @@ -295,11 +311,20 @@ def test_re_running_the_probe_on_a_shipped_unit_reproduces_its_scale(self): places=9) def test_deriving_from_the_jaw_travel_alone_would_be_short(self): - """反例：只除 85 mm 得到的比例矮了一截 —— 钉住分子里有压入量。""" - travel_rad = 1.409552 + """反例：只除 85 mm 得到的比例矮了一截 —— 钉住分子里有压入量。 + + 缺口正好是 ``压入量 / 行程``，不是一个粗差上限：出厂几何换过一代 + （``1.409552`` → ``1.170748`` rad），缺口从 ``0.71`` 涨到 ``0.85`` + mm/rad，写死的上限会随每次重新标定失效，等式不会。 + """ + with open(_FACTORY_CALIB) as f: + travel_rad = json.load(f)["travel_range_rad"] short = GripperGeometry.JAW_TRAVEL_MM / travel_rad - self.assertLess(short, 61.01229326764816) - self.assertLess(61.01229326764816 - short, 0.8) # 粗差，不是笔误量级 + self.assertLess(short, 73.45731105242119) + self.assertAlmostEqual( + 73.45731105242119 - short, + GripperGeometry.STOP_INSET_MM / travel_rad, + places=9) def test_a_coincident_travel_refuses_instead_of_inventing_a_scale(self): """两端止点重合时抛错，绝不再写一个凭空的 105.26 比例。"""