From a5f66f71753aebe8c6f93c3ba5ff82786435416d Mon Sep 17 00:00:00 2001
From: harleylara <harley.lara@outlook.com>
Date: Thu, 15 Feb 2024 11:24:10 +0100
Subject: [PATCH 1/6] add robot and link

Signed-off-by: harleylara <harley.lara@outlook.com>
---
 xsd/urdf.xsd | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/xsd/urdf.xsd b/xsd/urdf.xsd
index ccebfb26..f94ff12d 100644
--- a/xsd/urdf.xsd
+++ b/xsd/urdf.xsd
@@ -13,6 +13,18 @@
 	   xmlns="http://www.ros.org"
 	   elementFormDefault="qualified">
 
+  <!-- data type definitions -->
+  <xs:simpleType name="JointType">
+    <xs:restriction base="xs:string">
+      <xs:enumeration value="revolute"/>
+      <xs:enumeration value="continuous"/>
+      <xs:enumeration value="prismatic"/>
+      <xs:enumeration value="fixed"/>
+      <xs:enumeration value="floating"/>
+      <xs:enumeration value="planar"/>
+    </xs:restriction>
+  </xs:simpleType>
+
   <!-- pose node type -->
   <xs:complexType name="pose">
     <xs:attribute name="xyz" type="xs:string" default="0 0 0" />
@@ -293,7 +305,7 @@
 		  type="mimic" minOccurs="0" maxOccurs="1" />
     </xs:all>
     <xs:attribute name="name" type="xs:string" use="required" />
-    <xs:attribute name="type" type="xs:string" use="required" />
+    <xs:attribute name="type" type="JointType" use="required" />
   </xs:complexType>
 
   <!-- root node is always robot -->

From b8cd2485556bf5270dc194646578b094764ed94d Mon Sep 17 00:00:00 2001
From: harleylara <harley.lara@outlook.com>
Date: Thu, 15 Feb 2024 14:04:49 +0100
Subject: [PATCH 2/6] add sensor and gazebo element

Signed-off-by: harleylara <harley.lara@outlook.com>
---
 xsd/urdf.xsd | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/xsd/urdf.xsd b/xsd/urdf.xsd
index f94ff12d..130b64bd 100644
--- a/xsd/urdf.xsd
+++ b/xsd/urdf.xsd
@@ -154,7 +154,6 @@
       <xs:element name="verbose"
 		  type="verbose" minOccurs="0" maxOccurs="1" />
     </xs:sequence>
-    <!-- FIXME: used but not documented -->
     <xs:attribute name="name" type="xs:string" />
   </xs:complexType>
 
@@ -282,6 +281,67 @@
     <xs:attribute name="type" type="xs:string" use="required" />
   </xs:complexType>
 
+  <!-- image node type -->
+  <xs:complexType name="image">
+    <xs:attribute name="width" type="xs:unsignedInt" use="required" />
+    <xs:attribute name="height" type="xs:unsignedInt" use="required" />
+    <xs:attribute name="format" type="xs:string" use="required" />
+    <xs:attribute name="hfov" type="xs:double" use="required" />
+    <xs:attribute name="near" type="xs:double" use="required" />
+    <xs:attribute name="far" type="xs:double" use="required" />
+  </xs:complexType>
+
+  <!-- camera node type -->
+  <xs:complexType name="camera">
+    <xs:sequence>
+        <xs:element name="image"
+        type="image" minOccurs="0" maxOccurs="1" />
+    </xs:sequence>
+  </xs:complexType>
+
+  <!-- horizontal ray node type -->
+  <xs:complexType name="LaserRay">
+    <xs:attribute name="samples" type="xs:unsignedInt" default="1" />
+    <xs:attribute name="resolution" type="xs:unsignedInt" default="1"/>
+    <xs:attribute name="min_angle" type="xs:double" default="0" />
+    <xs:attribute name="max_angle" type="xs:double" default="0" />
+  </xs:complexType>
+
+  <!-- ray node type -->
+  <xs:complexType name="ray">
+    <xs:sequence>
+      <xs:element name="horizontal"
+          type="LaserRay" minOccurs="0" maxOccurs="1" />
+      <xs:element name="vertical"
+          type="LaserRay" minOccurs="0" maxOccurs="1" />
+    </xs:sequence>
+  </xs:complexType>
+
+  <!-- sensor node type -->
+  <xs:complexType name="sensor">
+    <xs:sequence>
+      <xs:element name="origin"
+		  type="pose" minOccurs="0" maxOccurs="1" />
+      <xs:element name="parent"
+		  type="parent" minOccurs="1" maxOccurs="1" />
+      <xs:choice>
+        <xs:element name="camera" type="camera" minOccurs="0" maxOccurs="1"/>
+        <xs:element name="ray" type="ray" minOccurs="0" maxOccurs="1" />
+      </xs:choice>
+    </xs:sequence>
+    <xs:attribute name="name" type="xs:string" use="required" />
+    <xs:attribute name="update_rate" type="xs:string" />
+  </xs:complexType>
+
+  <xs:complexType name="gazebo">
+      <!-- Allow any content within gazebo -->
+      <!-- for Gazebo Classic: https://classic.gazebosim.org/tutorials?tut=ros_urdf&cat=connect_ros -->
+      <!-- for newest Gazebo: http://sdformat.org/tutorials?tut=sdformat_urdf_extensions&cat=specification&-->
+      <xs:sequence>
+        <xs:any minOccurs="0" maxOccurs="unbounded" processContents="gazebo"/>
+      </xs:sequence>
+  </xs:complexType>
+
   <!-- joint node type -->
   <xs:complexType name="joint">
     <xs:all>
@@ -326,6 +386,12 @@
 		    type="transmission" minOccurs="0" maxOccurs="unbounded" />
 
 	<!-- FIXME: gazebo extension not supported -->
+  <xs:element name="gazebo"
+		    type="gazebo" minOccurs="0" maxOccurs="unbounded" />
+
+  <xs:element name="sensor"
+        type="sensor" minOccurs="0" maxOccurs="unbounded" />
+
       </xs:sequence>
       <xs:attribute name="name" type="xs:string" use="required" />
 

From 52bdf1c4d64190c67e0204db0f9f7894e17c0b24 Mon Sep 17 00:00:00 2001
From: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
Date: Tue, 16 Apr 2024 13:43:43 -0700
Subject: [PATCH 3/6] fix: set the gazebo's processContents to lax

Signed-off-by: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
---
 xsd/urdf.xsd | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/xsd/urdf.xsd b/xsd/urdf.xsd
index 130b64bd..01476393 100644
--- a/xsd/urdf.xsd
+++ b/xsd/urdf.xsd
@@ -333,14 +333,16 @@
     <xs:attribute name="update_rate" type="xs:string" />
   </xs:complexType>
 
-  <xs:complexType name="gazebo">
-      <!-- Allow any content within gazebo -->
-      <!-- for Gazebo Classic: https://classic.gazebosim.org/tutorials?tut=ros_urdf&cat=connect_ros -->
-      <!-- for newest Gazebo: http://sdformat.org/tutorials?tut=sdformat_urdf_extensions&cat=specification&-->
-      <xs:sequence>
-        <xs:any minOccurs="0" maxOccurs="unbounded" processContents="gazebo"/>
-      </xs:sequence>
-  </xs:complexType>
+    <xs:complexType name="gazebo">
+        <!-- Allow any content within gazebo -->
+        <!-- for Gazebo Classic:
+    https://classic.gazebosim.org/tutorials?tut=ros_urdf&cat=connect_ros -->
+        <!-- for newest Gazebo:
+    http://sdformat.org/tutorials?tut=sdformat_urdf_extensions&cat=specification&-->
+        <xs:sequence>
+            <xs:any minOccurs="0" maxOccurs="unbounded" processContents="lax" />
+        </xs:sequence>
+    </xs:complexType>
 
   <!-- joint node type -->
   <xs:complexType name="joint">

From 6c87c66942792e8e9975e4d2bd21b083dd0de671 Mon Sep 17 00:00:00 2001
From: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
Date: Tue, 16 Apr 2024 13:44:57 -0700
Subject: [PATCH 4/6] fix: fix the specification for link's visual/collision

Signed-off-by: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
---
 xsd/urdf.xsd | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/xsd/urdf.xsd b/xsd/urdf.xsd
index 01476393..455b93e7 100644
--- a/xsd/urdf.xsd
+++ b/xsd/urdf.xsd
@@ -159,14 +159,11 @@
 
   <!-- link node type -->
   <xs:complexType name="link">
-    <xs:all>
-      <xs:element name="inertial"
-		  type="inertial" minOccurs="0" maxOccurs="1" />
-      <xs:element name="visual"
-		  type="visual" minOccurs="0" maxOccurs="unbounded" />
-      <xs:element name="collision"
-		  type="collision" minOccurs="0" maxOccurs="unbounded" />
-    </xs:all>
+    <xs:choice minOccurs="0" maxOccurs="unbounded">
+      <xs:element name="inertial" type="inertial" />
+      <xs:element name="visual" type="visual" />
+      <xs:element name="collision" type="collision" />
+    </xs:choice>
     <xs:attribute name="name" type="xs:string" use="required" />
 
     <!-- FIXME: undocumented but used by PR2 -->

From 3517ca359c497339bf30f9879e102a5f18239c15 Mon Sep 17 00:00:00 2001
From: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
Date: Tue, 16 Apr 2024 14:29:58 -0700
Subject: [PATCH 5/6] fix: do not require a namespace for backwards
 compatibility

Signed-off-by: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
---
 xsd/urdf.xsd | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/xsd/urdf.xsd b/xsd/urdf.xsd
index 455b93e7..b9895ce0 100644
--- a/xsd/urdf.xsd
+++ b/xsd/urdf.xsd
@@ -9,9 +9,7 @@
 
   -->
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
-	   targetNamespace="http://www.ros.org"
-	   xmlns="http://www.ros.org"
-	   elementFormDefault="qualified">
+	   elementFormDefault="unqualified">
 
   <!-- data type definitions -->
   <xs:simpleType name="JointType">

From 5140442bf1061e337d3398695ad3b2d9797e93d7 Mon Sep 17 00:00:00 2001
From: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
Date: Thu, 30 May 2024 11:22:36 -0700
Subject: [PATCH 6/6] fix: only allow one inertial tag

Signed-off-by: Amin Yahyaabadi <aminyahyaabadi74@gmail.com>
---
 xsd/urdf.xsd | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xsd/urdf.xsd b/xsd/urdf.xsd
index b9895ce0..3f2e67f4 100644
--- a/xsd/urdf.xsd
+++ b/xsd/urdf.xsd
@@ -158,7 +158,7 @@
   <!-- link node type -->
   <xs:complexType name="link">
     <xs:choice minOccurs="0" maxOccurs="unbounded">
-      <xs:element name="inertial" type="inertial" />
+      <xs:element name="inertial" type="inertial" minOccurs="0" maxOccurs="1" />
       <xs:element name="visual" type="visual" />
       <xs:element name="collision" type="collision" />
     </xs:choice>