Determining camshaft deceleration rate from Follower?

In summary: Maybe the regenerative braking is used to keep the car on the same curve as the torque curve? In summary, a cam follower in a car would need a controller to constantly change the deceleration rate to keep the follower from riding along the torque curve.
  • #1
AmazingTrans
8
0
I am doing this as a hobby, trying to understanding some physics calculation for camshafts and following cam s,v,a,j.
All pictures in this thread are just samples that tie to nothing much, other than just images.

p34.png

7y94hR.png


1. From the 1st image above, the camshaft (emulated digital signal) is moving at a "constant speed", and the follower (motor) has the following plot. The camshaft has no boundaries in terms of velocity, acceleration, or jerk since it is digitally emulated.

I also have included the follower (which is a motor) properties. (Yes that's a tesla S motor. =D ) As we can see, the higher the speed of the motor, the lesser torque.

If the follower/motor is running at 120 mph and only capable of "d Nm" (reduced torque),
At point #2 of the cam plot and the camshaft decided to stop at a specific rate "x".
What would the camshaft deceleration formula look like if I want the follower/motor to not exceed 75% of the torque curve at that point ?

My goal here is to use to constantly change the camshaft deceleration rate such that the follower does not ride along its torque curve all the time.
 
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  • #2
I just thought, another good example of this application would be like today car (Nissan) where they use regenerative braking to brake the car.
If they were to run the car at higher speed, they have limited torque at that point. I would think the controller would constantly change its deceleration rate such that the motor follows the torque curve of the motor until it reaches low speed, then it will apply higher deceleration rate (more torque) when it is at lower speed.
 
  • #3
There seems to be something missing in your system description. How can a motor be a cam follower? I've done a lot of work with cams, but I've never seen anything that I would describe like this. Could you give us a sketch of the system you are talking about, please?
 
  • #4
AmazingTrans said:
I just thought, another good example of this application would be like today car (Nissan) where they use regenerative braking to brake the car.
If they were to run the car at higher speed, they have limited torque at that point. I would think the controller would constantly change its deceleration rate such that the motor follows the torque curve of the motor until it reaches low speed, then it will apply higher deceleration rate (more torque) when it is at lower speed.

Torque at high speed is probably limited because max power has been reached. I'm not sure if max power is limited by the motor or battery on the Tesla.

I can't think of a reason why, under regenerative braking, the torque should be limited to exactly same curve as under power.
 

1. What is the purpose of determining camshaft deceleration rate from follower?

The purpose of determining camshaft deceleration rate from follower is to accurately measure the rate at which the camshaft slows down during the rotation cycle. This information is important for designing efficient and precise engine performance, as well as understanding the wear and tear on the camshaft and other engine components.

2. How is camshaft deceleration rate from follower measured?

Camshaft deceleration rate from follower is typically measured using a degree wheel and dial indicator. The degree wheel is attached to the camshaft and the dial indicator is placed on the follower. As the camshaft rotates, the degree wheel indicates the angle of rotation and the dial indicator measures the corresponding movement of the follower. This data can then be used to calculate the deceleration rate.

3. What factors can affect camshaft deceleration rate from follower?

Several factors can affect camshaft deceleration rate from follower, including engine speed, oil viscosity, and camshaft design. Higher engine speeds can result in faster deceleration rates, while thicker oil can slow down the deceleration. Additionally, different camshaft designs, such as lobe shape and material, can also impact the deceleration rate.

4. Why is it important to accurately measure camshaft deceleration rate from follower?

Accurately measuring camshaft deceleration rate from follower is crucial for optimizing engine performance and ensuring the longevity of engine components. If the deceleration rate is too fast, it can cause excessive wear on the camshaft and other parts, leading to decreased engine efficiency and potentially costly repairs. On the other hand, if the deceleration rate is too slow, it can result in poor engine performance and reduced power output.

5. How can camshaft deceleration rate from follower be improved?

Camshaft deceleration rate from follower can be improved by carefully selecting the appropriate camshaft design and material for the specific engine and its intended use. Regular maintenance, such as changing the oil and ensuring proper lubrication, can also help improve the deceleration rate. Additionally, using high-quality components and accurately measuring the deceleration rate can help identify any issues and make necessary adjustments for optimal engine performance.

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