add xarm_user_params.yaml

- Default configuration: xarm_api/config/xarm_params.yaml
- Custom configuration: xarm_api/config/xarm_user_params.yaml
- When reading the configuration, the custom configuration will overwrite the content of the same field in the default configuration

.gitignore

@@ -1,4 +1,5 @@
 .vscode/
 .idea/
 *bak/
-ignore_*
+ignore_*
+xarm_api/config/xarm_user_params.yaml

ReadMe.md

@@ -98,7 +98,7 @@ __Reminder 3： All following instructions will base on xArm6，please use prope
 - ### 5.4 xarm_api
     This package is a ros wrapper of "xarm_sdk"，functions are implemented as ros service or ros topic，communications with real xArm in "xarm_ros2" are based on the services and topics provided in this part. All the services and topics are under xarm/ namespace by default(unless 'hw_ns' parameter is specified)，e.g. full name for "joint_states" is actually "xarm/joint_states".  
 
-    - __services__: the name of provided services are the same with the corresponding function in SDK, however, whether to activate the service is up to the configuration under the "services" domain in ```xarm_api/config/xarm_params.yaml```. The defined service can only be activated at initialization if that service is configured to ```true```.  
+    - __services__: the name of provided services are the same with the corresponding function in SDK, however, whether to activate the service is up to the configuration under the "services" domain in ```xarm_api/config/xarm_params.yaml``` and ```xarm_api/config/xarm_user_params.yaml```. The defined service can only be activated at initialization if that service is configured to ```true```. If you need to customize the parameters, please create a file ```xarm_api/config/xarm_user_params.yaml``` to modify, the format, refer to ```xarm_api/config/xarm_params.yaml```.
         ```
         services:
             motion_enable: true

ReadMe_cn.md

@@ -95,7 +95,7 @@ __注意3： 以下启动说明以6轴为例，5轴和7轴的用法只需找到
     此模块是针对xarm_sdk封装，提供对应的ros service和ros topic，整个xarm_ros2是通过使用此模块的service和topic来和机械臂的通信的
     所有service和topic默认都处于xarm/空间下(除非指定了hw_ns参数)，即joint_states的完整名字为xarm/joint_states
 
-    - __services__: 所有提供的service的名字和SDK中的API名字是对应的，但是否创建对应的服务是根据```xarm_api/config/xarm_params.yaml```的services来决定的，只有当services下对应的service的值为```true```时才会创建对应的service。  
+    - __services__: 所有提供的service的名字和SDK中的API名字是对应的，但是否创建对应的服务是根据```xarm_api/config/xarm_params.yaml```和```xarm_api/config/xarm_user_params.yaml```的services来决定的，只有当services下对应的service的值为```true```时才会创建对应的service，如果需要自定义参数，请创建```xarm_api/config/xarm_user_params.yaml```文件来修改，格式参照```xarm_api/config/xarm_params.yaml```。
 
         ```
         services:

xarm_api/config/xarm_params.yaml

@@ -1,3 +1,5 @@
+# Please do not modify this file, this configuration is the default configuration
+# if you need to modify, please modify xarm_user_params.yaml
 xarm_driver:
   ros__parameters:
     DOF: 7

xarm_api/launch/_xarm_driver.launch.py

@@ -16,17 +16,38 @@
 from launch_ros.actions import Node
 
 
-def generate_xarm_params(xarm_params_path, ros_namespace=''):
-    if ros_namespace:
-        with open(xarm_params_path, 'r') as f:
+def merge_dict(dict1, dict2):
+    for k, v in dict1.items():
+        try:
+            if k not in dict2:
+                continue
+            if isinstance(v, dict):
+                merge_dict(v, dict2[k])
+            else:
+                dict1[k] = dict2[k]
+        except Exception as e:
+            pass
+
+
+def generate_xarm_params(xarm_default_params_path, xarm_user_params_path=None, ros_namespace=''):
+    if not os.path.exists(xarm_user_params_path):
+        xarm_user_params_path = None
+    if ros_namespace or (xarm_user_params_path is not None and xarm_default_params_path != xarm_user_params_path):
+        with open(xarm_default_params_path, 'r') as f:
             ros2_control_params_yaml = yaml.safe_load(f)
-        xarm_params_yaml = {
-            ros_namespace: ros2_control_params_yaml
-        }
+        with open(xarm_user_params_path, 'r') as f:
+            ros2_control_user_params_yaml = yaml.safe_load(f)
+        merge_dict(ros2_control_params_yaml, ros2_control_user_params_yaml)
+        if ros_namespace:
+            xarm_params_yaml = {
+                ros_namespace: ros2_control_params_yaml
+            }
+        else:
+            xarm_params_yaml = ros2_control_params_yaml
         with NamedTemporaryFile(mode='w', prefix='launch_params_', delete=False) as h:
             yaml.dump(xarm_params_yaml, h, default_flow_style=False)
             return h.name
-    return xarm_params_path
+    return xarm_default_params_path
 
 
 def launch_setup(context, *args, **kwargs):
@@ -70,6 +91,7 @@ def launch_setup(context, *args, **kwargs):
 
     xarm_params = generate_xarm_params(
         os.path.join(get_package_share_directory('xarm_api'), 'config', 'xarm_params.yaml'),
+        os.path.join(get_package_share_directory('xarm_api'), 'config', 'xarm_user_params.yaml'),
         LaunchConfiguration('ros_namespace', default='').perform(context)
     )