i looking to build some kind of a sensor system which can detect human or object around a vehicle in 360 degree upto 4-5 mtr away. as it going to be outdoor must be water proof. i have tried using JSN-SR04t but its angle is very limited plus it only detecting big objects, any person is not accurately getting detected which is very important. A HC-sro4 on servo motor can work but its not waterproof. i am looking for other senors or idea on how to accomplish this.
Not enough information to offer useful suggestions. You need to flesh out you request with lots more information like...
Do you need to detect people/objects while the vehicle is moving or just while it's stationary.
Is the detector to be connected to the vehicle or connected elsewhere to overlook a parked vehicle.
Do you need to detect in light/darkness.
Try using the PIR sensor.
Is it OK to detect not just humans but to also detect other large objects (passing cars) or other moving objects (the neigbour's cat)?
You complain the HC-SR04 detects only "large objects", while my experience with those sensors is that they detect things much smaller than an average person, even an average small child. So they should be quite suitable for the object size you want to detect.
Waterproof rear ultrasound add-on kits are readily available for cars - not sure how well multiple sets would interact though. https://www.amazon.co.uk/Parking-Reversing-Sensor-Sensors-Buzzer/dp/B002ATACEI
Riva:
Not enough information to offer useful suggestions. You need to flesh out you request with lots more information like...Do you need to detect people/objects while the vehicle is moving or just while it's stationary.
Is the detector to be connected to the vehicle or connected elsewhere to overlook a parked vehicle.
Do you need to detect in light/darkness.
It is for detecting humans and any object, more like to work as a proximity sensor, to detect anything coming close to the vehicle upto 4- 5 mtr. it will be connected on the vehicle at all times while moving and stationary and need to detect both at night and day. HC-SR04 works very nicely but only issue with it, it is not waterproof.
This system is to be fitted on big moving machinaries, in which anything or anyone closer then 3 mtrs are not visible both front and back. its is for the operator to get an alarm when something has come 3 mtr near to it specially people.
the problem is we do not have different types of sensors freely available in our country. and ordering it cost almost 10 times the original amount due to shipping or airflight. so i cant test different types of sensors. PIR sensor is good for human detection but im not sure if it will be good option due to very weather over here and machine working near hot asphalts.
currently we are using Car parking sensor as a detection method but they are programmed only to detect upto 1.5 mtr, which is the problem, we need range upto 4-5 mtr.
So it's like a safety device. Then you must keep in consideration the cost of failure as well, and you're best off looking for off the shelf solutions from reputable suppliers. Then if it goes wrong after all, it's not your failure.