V-REP 力传感器

力传感器简介

一个力传感器可以同时测出三个方向的力和力矩， VREP中力传感器的一大用处就是用来测量机器人与外界环境交互时的接触力，比如检测机械手爪的夹持力或是机器人脚底的压力分布等信息。通常需要将力传感器添加在末端（手指或脚底板上）然后再连接一个接触体。

UR5模型中自带一个名为UR5_connection的ForceSensor

力传感器参数设置

这里模型的参数已经配置好，没有其他需求的情况下暂时不需要修改。

参数设置如下：

Filter: when force or torque data is acquired by the force sensor, then it is accumulated and can be filtered in order to obtain less jittery values.

Sample size: the number of values that should be used for the filter. 1 will not filter values (raw output).

Average value: if selected, then the force sensor will deliver average values (average of sample size values).

Median value: if selected, then the force sensor will deliver median values (median of sample sizevalues).

Breaking settings: this section allows to set-up some automatic breaking conditions and behavior for a force sensor. Alternatively, the user can programmatically handle breaking conditions and behavior by accessing the appropriate functions.

Force threshold: the amplitude of the force vector that triggers a threshold violation.

Torque threshold: the amplitude of the torque vector that triggers a threshold violation

Consecutive threshold violations for breaking: the number of consecutive times the sensor is allowed to violate a threshold before breaking.

Object size: size of the sensor’s 3D representation. This has no functional effect.

Adjust color A / B: allows adjusting the two colors of a force sensor.

Graph输出配置

1.添加Graph

打开scene——UR5PegInHole.ttt

仿真界面右键，Add-graph

2.参数设置

一个Graph可以选择多个变量输出

Python参数读取

只需要用simxReadForceSensor读取即可

#!/usr/bin/env python
# encoding: utf-8

"""
The program is used to get the force sensor's force and torque.
Use the scene：UR5PegInHole2.ttt

@Author: Zane
@Contact: ely.hzb@gmail.com
@File: forceSensor.py   
@Time: 2019-07-31 15:55
"""
import vrep
import sys
import numpy as np
import math
import matplotlib.pyplot as mpl
import time

##### 建立Python与V-REP的通信

print('Program started')
# 关闭潜在的连接
vrep.simxFinish(-1)
# 每隔0.2s检测一次，直到连接上V-rep

clientID = vrep.simxStart('127.0.0.1', 19997, True, True, 5000, 5)
print("Connection success")

# 开启仿真
vrep.simxStartSimulation(clientID, vrep.simx_opmode_blocking)
print("Simulation start")

##### 参数定义
sensorName = 'UR5_connection'

##### 获取Handle
errorCode, returnHandle = vrep.simxGetObjectHandle(clientID, sensorName, vrep.simx_opmode_blocking)
forceSensorHandle = returnHandle

print('Handles available!') 


##### 读取力传感器的力与力矩大小
while vrep.simxGetConnectionId(clientID) != -1:
    # simx_opmode_streaming初始化，此时不会读取到值
    errorCode,state,forceVector,torqueVector=vrep.simxReadForceSensor(clientID,forceSensorHandle,vrep.simx_opmode_streaming)
    # 不能同时两次读取，否则读不到值
    time.sleep(1)
    # simx_opmode_buffer读取forceVector,torqueVector
    errorCode,state,forceVector,torqueVector=vrep.simxReadForceSensor(clientID,forceSensorHandle,vrep.simx_opmode_buffer)
    # 输出xyz的力
    print(forceVector)
    # 输出xyz的力矩
    print(torqueVector)

测试结果