iconv() [function.iconv]: detected an illegal character in input string

<script>
function saveCsv(){
var tag = $('#posSelect').val();
$.ajaxFileUpload({
url:'/admmeeting/explore',//用于文件上传的服务器端请求地址
secureuri:false,//一般设置为false
fileElementId:'file_upload',//文件上传空间的id属性  <input type="file" id="file" name="file" />
data:{iId:tag},
dataType: 'json',//返回值类型 一般设置为json
success: function (data, status)  //服务器成功响应处理函数
{
if(data.success){
alert('导入成功');
return;
}else{
alert(data.msg);
}

}
})
}
</script>

if(Input::has('iId')){
$iId = trim(intval(Input::get('iId')));
//获取主题的op
$oYuzhiDic  = RepresentMeetingYuzhi::find($iId);
if($oYuzhiDic){
$op = $oYuzhiDic->op;
}else{
echo json_encode(array('success'=>false,'msg'=>'该主题不存在'));
exit;
}
}else{
echo json_encode(array('success'=>false,'msg'=>'请选择主题'));
exit;
}
if(Input::hasFile('file_upload')){
setlocale(LC_ALL, 'zh_CN');
ini_set('max_execution_time', '600');//最大执行时间600秒
$file = Input::file('file_upload');
$fileType = strtolower($file->getClientOriginalExtension());
if($fileType=='csv'){
$reName = md5(date('YmdHis'));
$file->move(public_path('uploadfile/meetingyuzhi/'),$reName);
$fh = fopen(public_path('uploadfile/meetingyuzhi/'.$reName), 'r');
$data = NULL;
$insertUser = array();
$data = fgetcsv($fh);//去掉头
$user = array();
//获取所有代表的信息
$oRep = Represent::whereNull('deleted_at')->get();
$aUser = array();

foreach($oRep as $rep){
$aUser[$rep->cwid] = array($rep->id,$rep->name,$rep->region_id,$rep->area_id,$rep->cwid,$op);
}
while($data = fgetcsv($fh)){
//每次插入1k条数据

$user['uid'] = $aUser[$data[0]][0];
$user['name'] = $aUser[$data[0]][1];
$user['region_id'] =$aUser[$data[0]][2];
$user['area_id'] = $aUser[$data[0]][3];
$user['cwid'] = $aUser[$data[0]][4];
$user['op'] = $aUser[$data[0]][5];
$insertUser[] = $user;
if(count($insertUser) == 1000){
try{
DB::table('power_users')->insert($insertUser);
}catch(Exception $e){
echo json_encode(array('success'=>false,'msg'=>'部分数据格式不正确，或者已经存在'));
exit;
}
$insertUser = array();
}
}

}
//不足一千的进行操作
try{
if(count($insertUser)>0){
DB::table('power_users')->insert($insertUser);
}
}catch(
b2c3
Exception $e){
echo json_encode(array('success'=>false,'msg'=>'部分数据格式不正确，或者已经存在'));
exit;
}
echo json_encode(array('success'=>true));
}else{
echo json_encode(array('success'=>false,'msg'=>'请选择csv格式文件'));
}
}else{
echo json_encode(array('success'=>false,'msg'=>'请选择文件'));
}
}